Browsing by Author "Asrat, Daniel(PhD)"

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    Assessment of Bacterial Profile and Antimicrobial Susceptibility Pattern of Catheter-Associated Urinary Tract Infections in Comparison with non-Catheterized Urinary Tract Infections in Jimma University Hospital, Southwest Ethiopia
    (Addis Ababa University, 2005-06) Teshager, Lule; Asrat, Daniel(PhD)
    Urinary tract infections (UTIs) are among the most common bacterial infection. They have become the most common hospital acquired infections, accounting for as many as 35% of nosocomial infections, and are usually associated with catheterization. The aim of this study is to assess the bacterial profile and antimicrbial resistance pattern of catheter associated urinary tract infection in comparison with non-catheter associated UTI. One hundred and twenty urine specimens (30 from catheterized patients and 90 from non-catheterized patients with symptoms of UTI) were screened for the presence of significant bacteruria from January to March 2005. Bacteriological screening of catheterized urine and clean catch mid-stream urine revealed that 13/30 (43.3%) and 20/90 (22.3%) had significant bacteriuria, respectively (P<0.05). All samples taken from patients who have been catheterized for 2 weeks or more showed significant bacteruria. In both group the rate of infection was higher in female patients. Older patients (>50years old) were found to be the most affected age group (46%) among catheterized patients whereas most of the non-catheterized patients with significant bacteruria belonged to age group 11-12 years. Among catheterized patients, Escherichia coli and Klebsiella species were found to be the most frequently isolated pathogens (each of them accounts 23 %) followed by coagulase negative Staphylococci (15 %). The most frequently isolated species from non-catheterized patients was Klebsiella (40 %) followed by E. coli (30 %). Resistance rates (56.3 % to 100%) to Ampicillin, amoxicillin, cephalexin, carbenicillin, and Trimethoprime /sulfamethoxazole were observed in all organisms isolated from both groups. In addition, resistance rates to gentamicin, nitrofurantoin, and nalidixic acid were observed in all bacteria isolated from catheterized patients. In general, in this study, high level multidrug resistance in both groups indicated that it is time to reconsider the empirical use of the commonly used antimicrobial agents in Ethiopia. Particularly, increasing vii resistance in pathogens isolated from catheterized patients is frustrating. Because the most important risk factors for UTI is duration of catheterization indwelling urinary catheterization should be avoided or at least minimized
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    Assessment of Specific Immune Responses to Tuberculosis in HIV Infected Patients Before and During Highly Active Antiretroviral Treatment (HAART)
    (Addis Ababa University, 2009-03) Berhanu, Tesfaye; Asrat, Daniel(PhD); Woldeamanuel, Yimtubezinash (PhD)
    BACKGROUND: HAART greatly reduces the risk of developing tuberculosis in HIVinfected persons. However, individuals who initiate HAART may still be reported as having TB, either because they are developing active TB due to persistent immunodeficiency or because they have sub clinical TB that becomes apparent in the immune reconstitution inflammatory syndrome (IRIS). Despite the severity of the problem, little information is available on the extent to which HAART restores TB specific immune response or CD4 cell and characteristics of patients who develop TB while taking HAART and proportion of immune reconstitution syndrome associated with TB. OBJECTIVES: To assess specific immune response to tuberculosis in HIV-1 infected patients before and during HAART and to assess the characteristics of patients who developed ART associated TB and to determine the incidence rate of TB IRIS. METHODS: In a longitudinal prospective cohort study, 177 study participants naive to HAART were enrolled and followed for six months after starting HAART at ALERT Hospital, Addis Ababa Ethiopia. The study period was from June 2006 to September 2008. Blood samples were collected before initiation of HAART (at baseline), at 3rd and 6th month of HAART and at occurrence of suspected TB IRIS. T lymphocyte sub set enumerated and the immune response to tuberculosis was assessed in vitro, using ELISPOT assay in PBMC stimulated with TB antigens (PPD, ESAT-6, and CFP-10), and in vivo using tuberculin skin test (TST) at the specified time points. RESULTS: Recovery of TB specific immune response: The proportion of TST positive responses increased significantly from baseline 17.5% to 26.8% at 3rd month and to 28.9% at the 6th month (p= 0.02). TST response increased significantly among groups with CD4 cell count <50 cells/mm3 when the group is stratified according to baseline CD4 cell count and among group with active TB at baseline investigation when the group is stratified according to baseline TB status. Quantitative IFN-γ ELISPOT response to TB antigens (PPD, ESAT-6 and CFP-10) also increased after HAART in the whole cohort. Median SFC/million to PPD xiii and ESAT-6 significantly increased among group with baseline CD4<50 cells/mm3 when the group is stratified according to baseline CD4 cell count. Although the difference was not statistically significant (except for quantitative ELSPOT response to PPD), the proportion of TST response and median SFC/million ELISPOT response to TB antigens after HAART were also higher in those with baseline CD4 ≥100 cells/mm3 than < 100 cells/mm3. ART associated TB, unmasking and paradoxical TB IRIS: the incidence rate of ART associated TB in our cohort was 12.7 cases /100 PY during the first 6 months of HAART. The majority (62.5%) of TB cases occurred within the first month of HAART. Baseline TST response > 5 mm induration, baseline hemoglobin < 12 gm/dl and being male were the strongest predictors of occurrence of TB during HAART. Only 3/8 (37.5%) episodes of TB were presented as unmasking tuberculosis IRIS. The proportion of paradoxical IRIS was 9.6 % (3/31) and the incidence rate was 22.5 cases per 100 persons per year. CONCLUSIONS AND RECOMMENDATIONS: The majority of the study participants attained CD4 cell counts above the zone of severe immunodeficiency within the first 3 months of treatment. However, the relative risk of attaining CD4 cell > 200 cells/mm3 decreased significantly with decreasing baseline CD4 cell count. Thus, individuals who initiated HAART with CD4 < 50 cells/mm3 are likely to have high risk of morbidity and mortality for longer period. This underscores the need of designing strategy to identify and treat patients before they get into a stage of profound CD4 lymphcytopenia. Our study indicates that TB specific T cell repertoire may not be totally lost in HIV infected individuals with CD4 < 50 cells/ mm3 and their levels can still be improved by HAART. Our findings provide useful baseline information for further research to assess overall potential of HAART in the restoration of immunity to tuberculosis. Finally, in this study, we observed a high rate of tuberculosis in our cohort during the initial months of HAART indicating the need for careful screening for TB before initiation of HAART. More sensitive and specific diagnostic methods for TB may assist in early diagnosis. In addition, our study confirmed that a sub set of patients who developed TB during HAART manifested as IRIS. Key words: Tuberculosis, CD4 cell count, IRIS, HAART, immune response and Ethiopia
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    Bacterial Profile and Drug Susceptibility Pattern of Urinary Tract Infection in Pregnant Women Attending Antenatal Care at Mekelle Hospital, Mekelle, Northern Ethiopia
    (Addis Ababa University, 2014-12) Tsegay, Ephrem; Asrat, Daniel(PhD); Woldeamanuel, Yimtubezenash(PhD)
    Background: Urinary tract infection (UTI) in pregnancy is associated with significant morbidity for both the mother and the baby. However, little is known about UTI in pregnancy in the study area. Antimicrobial resistance among the pathogens that cause UTI is also increasing and is a major health problem in the treatment. Hence, proper investigation and prompt treatment are needed to prevent serious life threatening condition and morbidity due to UTI that can occur in pregnant women. Objectives: To identify the prevalent bacterial isolates that cause UTI and assess their antibiotic susceptibility pattern among symptomatic and asymptomatic pregnant women attending antenatal care in Mekele Hospital, Tigray Region. Methods: A cross sectional study was carried out from January to August 2014 on a total of 168 pregnant women with and without symptoms of UTI that attended antenatal care at Mekelle Hospital. Mid-stream urine samples were collected and inoculated onto Cystine Lactose Electrolyte Deficient medium (CLED). Colony counts yielding bacterial growth of ≥105cfu/ml is regarded as significant bacteriuria. Pure isolates of bacterial pathogen were characterized by colony morphology, gram-stain, and standard biochemical procedures. A standard method of agar disc diffusion susceptibility testing method was used to determine susceptibility patterns of the isolates. Results: In this study, the overall prevalence of UTI was 11.9%. Of this bacteriological screening of midstream urine specimens showed that 11.3% and 15.4%, had significant bacteriuria in asymptomatic and symptomatic group respectively. Prevalence of UTI was significantly associated with previous history of catheterization and urinary tract infection (p<0.05). Escherichia coli was the most frequently isolated organism 6(30%) followed by coagulase negative staphylococcus 5(25%), Staphylococcus aureus 3 (15%), and Klebsiella pneumoniae 3 (15%). Gram negative and Gram positive bacteria accounted for (60) and (40%) respectively. Gram-negative isolates showed resistance rate of 100% to ampicillin and resistance against ciprofloxacin, norfloxacin, gentamycin, amoxicillinclavulnic acid, trimethoprim/sulfamethoxazole and chloramphenicol ranged from 25- 50%. However, all Gram negative bacterial isolates revealed low level of resistance VIII (16.7%) against nitrofurantoin and ceftriaxone. The rates of susceptibility of Grampositives to ceftriaxone, doxycycline, amoxicillin-clavulnic acid and vancomycin range from 62.5% - 100%. And they showed resistance rate of 75% and 87.5% to penicillin and ampicillin, respectively. Multiple drug resistance (resistance to two or more drugs) was observed in 90 % of the isolates. Conclusions and Recommendations:- Significant bacteriuria has been observed from both symptomatic and asymptomatic pregnant women. Majority of the isolates were resistant to the commonly prescribed antibiotics. This calls for an early screening of all pregnant women for UTI and those found to be infected need to be treated with an appropriate drug to avoid complications. Keywords: Bacterial profile, antibiotic resistance, pregnancy, Mekelle, Ethiopia
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    Bacteriology of Open Fracture Wounds in Tikur Anbessa University Hospital, Addis Ababa, Ethiopia
    (Addis Ababa University, 2009-05) Abraham, Yishak; Asrat, Daniel(PhD)
    Open fractures are those exposed to the out side environment through a skin wound. They are at risk of complications such as infected non-union and other co-morbid conditions. Sixty to seventy percent of compound fractures are believed to be contaminated with bacteria at the time of injury from both skin and environment. Infection of open fractures depends on the microbial and host factors. In Ethiopia, a high incidence of open fracture wound infection is suspected though the magnitude of the problem is not known. No documented report on bacterial isolates from open fracture wounds and their drug resistance pattern. During a period of November 2007 and May 2008, a cross-sectional prospective study was conducted to determine the bacteriology of open fracture wounds of 191 informed and consented patients who visited the orthopedic surgery department of Tikur Anbessa University Hospital, Addis Ababa, Ethiopia. The modified Gustilo and Anderson (G-A) grading of open fractures based on severity and extent of soft-tissue injury was used to categorize the open fractures. The clinical features of the open fracture wounds were assessed and wound swab specimens were collected using Levine’s technique from each patient. All of the wound specimens were processed for microscopic examination, culture and sensitivity testing. The causes of the fractures varied, but most of the open fractures were caused by car accidents (37.2%) and occurred in lower extremities bones (60.0%). Of the 191 patients, 82.7% were males and 17.3% were females (p < 0.05) resulting in an overall male to female ratio of 4.8:1. The average age of the patients was 31.55 years (age range 4 to 75 years). According to G-A grading, 23.0% of the fractures were grade I; 41.5% were grade II; 14.0% were grade IIIA; 5.5% were grade IIIB and 16.0% were grade IIIC. Of the 200 wound specimens examined by gram stain, 30.5% were positive for the presence of bacteria. Out of the 200 wound specimens cultured, 82 (41%) were positive for bacteria. Of the culture-positive wounds, 51.2% showed mono-microbial growth and 48.8% showed polymicrobial growth. In general, a total of 162 bacterial pathogens were isolated from the open fracture wounds sampled. Staphylococcus aureus was the dominant isolate (14.8%) followed by Acinetobacter spp. (11.4%). The gram-positive and gram-negative bacteria accounted for 34.0% and 66.0%, respectively (p< 0.05). All gram-positive bacterial isolates showed low level of resistance (<60%) to all antibiotics tested except for ampicillin and penicillin to which they showed intermediate level of resistance (60-80%). Most gramviii positive isolates, 29/55 (52.7%) showed multiple drug resistance (resistance to three or more drugs). All Clostridium spp. were susceptible to tetracycline, doxycycline, and kanamycin and showed low level of resistance (<60%) against chloramphenicol, clindamycin and penicillin. All gram negative bacterial isolates showed low level of resistance (<60%) to all antibiotics tested except for ampicillin and amoxicillin (60-80%, intermediate level resistance). Fifty-one percent of the gram negative bacterial isolates were identified as multiple drug resistant. In conclusion, the present study showed that road traffic accident was the commonest cause of open fractures. Most fractures occurred in lower extremities. Staphylococcus aureus was the commonest isolate associated with open fracture wound infection. Gentamicin, ciprofloxacin and norfloxacin were the most effective drugs against the tested gram positive and gram negative bacteria. The findings of this study will give valuable information for establishing empiric therapeutic approaches for the management of open fracture wound infections. In addition, the findings underscore the need for routine microbiological investigation of open fracture wounds and monitorring antimicrobial resistance pattern for the use of prophylactic and therapeutic antimicrobials. Key words: Open fracture wounds, Bacterial isolates, Antimicrobial susceptibility testing
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    Characterization of Group A Streptococci Isolated from Throat of Healthy School Children in Ethiopia
    (Addis Ababa University, 2005-07) Abdissa, Alemseged; Asrat, Daniel(PhD)
    Post-streptococcal complications such as acute rheumatic fever (ARF) are reported to be common among Ethiopian children. Little is known, however, about the epidemiology of b-hemolytic streptococci, and Group A streptococci (GAS) in Ethiopia. A total of 937 randomly selected healthy schoolchildren residing in Addis Ababa (n=491), Gondar (n=265) and Dire-Dawa (n=181) were studied during a period November 2004 and January 2005. Throat specimens were collected and b-hemolytic streptococci were isolated on Columbia blood agar supplemented with Colistin-oxolonic acid. Gram reaction, catalase test Bacitracin susceptibility test and serological test were used to differentiate the organisms. In addition biochemical testing (API) was used to identify the species of isolates that could not be serogrouped. GAS were the predominant b-hemolytic streptococci with a proportion of 55% in Addis Ababa, 61% in Gondar, and 47% in Dire-Dawa of the serogroups. The carrier rate of GAS in healthy schoolchildren was 10.8% in Addis Ababa, 8.7% in Gondar and 9.4% in Dire- Dawa. Seven isolates that were nongroupable confirmed to be Streptococcus constellatus with API biochemical testing. Molecular (emm gene) typing was performed on 82 GAS isolates and 44 different emm types were detected. Among the 82 isolates 18 strains belonged to 13 new, previously undescribed emm subtypes. Known rheumatogenic strains accounted for 56% of isolates in Addis Ababa, 35% in Gondar and 0% in Dire-Dawa. Of the emm types prevalent in the study communities, 60% were not included in the 26 valent vaccine that was formulated for western countries. The distribution of emm types described in this study was compared with the study conducted on isolates collected 13 years ago in Addis Ababa, only 3/20 emm types identified in earlier study had been represented in the present study. Moreover, the type, which was predominant in the previous study, was not detected in the current one and the type that was predominant in our study was not detected in the previous one. x In conclusion, Group A was the most frequent serogroup among b hemolytic streptococci isolated from throat swabs of healthy schoolchildren in the selected three sites of Ethiopia and the carriage rate of GAS ranged from 8.7 to 10.8%. Tremendous diversity of emm types was observed in this first large scale emm type survey in Africa, and a significant proportion of them are known to be rheumatogenic. The association of the prevalent emm types not previously linked to rheumatic fever needs to be explored particularly in Dire-Dawa. Key Words: Beta-hemolytic streptococci, Group A Streptococci, Streptococcus pyogenes, M protein, emm typing
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    Epidemiology and Drug Resistance Pattern of Mycobacterium Tuberculosis in North West Ethiopia: Resource Limited Settings
    (Addis Ababa University, 2014-08) Airgecho, Tekle; Woldeamanuel, Yimtubezinash (PhD); Asrat, Daniel(PhD)
    Background: Tuberculosis (TB) remains a major global health problem and ranks as the second leading cause of death among deaths caused by infectious diseases worldwide. Despite the availability of short course regimens as first line anti tuberculosis drugs, emergence of drug resistant Mycobacterium tuberculosis strains pose a major challenge to the prevention and control efforts of national tuberculosis programs (NTPs). In developing countries, including Ethiopia, the burden of tuberculosis and /or drug resistance profile of M.tuberculosis remains largely unexplored, mainly due to lack of quality controlled second line laboratory tests. Objectives: To assess the mycobacterial genotypic diversity and drug resistance pattern of M. tuberculosis complex in North West Ethiopia: resource limited settings. Moreover, it was to assess the knowledge, attitude and practice (KAP) of TB suspects towards tuberculosis Methods: Health care institution-based cross-sectional study was designed and conducted to assess: 1) Mycobacterial strain diversity 2) drug resistance pattern of Mycobacterium tuberculosis and 3) to evaluate the KAP of TB suspects towards TB in North West Ethiopia: resource limited settings. Study Subjects from health facilities in Benishangul Gumuz region and Awi zone of Amhara region who consented to participate were included in the study. 112 Smear positive samples were collected from study participants, stored and transported to Armauer Hansen Research Institute (AHRI) TB laboratory. At AHRI laboratory Lowenstein–Jensen (LJ) culture, drug susceptibility testing, RD9 deletion typing and Spoligotyping were performed from April 2013 through June 2014. Drug susceptibility testing (DST) was done by the proportion method on 24 well plates using 7H10 medium. The isolates were further characterized by spoligotyping and compared with updated SpolDB4.0 database to identify the circulating strains. Information for KAP study was collected on well-structured questionnaires. SPSS V.20 statistical software was used for data entry, data cleaning and analysis. Results: DST result of isolates from 87 samples showed one or more drug resistance in 16.5% with higher rate of monoresistance to isoniazid (6.9%). Multidrug resistance of 2(2.3%) was observed with 1(1.3%) and 1(8.3%) distribution among new and retreatment cases respectively. From 75 Mycobacterium tuberculosis isolates typed, 39 particular spoligotype patterns with 32(42.7%) of “New” isolates was observed. SIT289, SIT53, SIT149, SIT37 and SIT134 were the X predominant strains circulating in the study region with proportion of 14.7%, 12.0%, 8.0%, 5.3% and 4.0% respectively From 383 participants involved for KAP study 231(60.3%) were male and 152(39.7%) were female. Most frequent respondents’ sources of information about TB were health professionals in 131(34.2%) and 20(5.2%) had never heard about tuberculosis. 254(66.3%) knew that TB transmission is aerosol while 81(21.1%) do not know about it. 223(58.2%) responded TB transmission can be prevented by covering mouth and nose while coughing and sneezing but 125(32.6%) do not know about means of TB prevention. Respondents’ lack of knowledge 169(49.6%) and 63(18.5%) were reasoned accessibility and affordability for their delay in health service seeking behavior. Conclusion: Although current level of drug resistance appears to be low, the risk for a sudden increase is high because of the relatively higher mono resistance to INH. It is essential to maintain high quality DOTS in the area to keep MDR low. Majority of respondents also had poor knowledge and several misconceptions about TB that needs to be addressed through continuous health education on cause, transmission, prevention, treatment and services available. Key words: Mycobacterium tuberculosis, Strain diversity, Drug resistance, KAP, Benishangul Gumuz region, Northwest Ethiopia
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    Phenotypic and Molecular Characterization of Non-typhoidal Salmonella Species in Humans and Animals in Central Ethiopia and Inhibition of Biofilm Formation Using Small Molecule Adenosine Mimetics
    (Addis Ababa University, 2016-06) Eguale, Tadesse; Asrat, Daniel(PhD); Eingidawork, Ephrem (PhD)
    This dissertation reports prevalence, serotype distribution and phenotypic and genotypic characteristics of non-typhoidal Salmonella (NTS) in humans and animals in central Ethiopia and effect of small molecule adenosine mimetic compounds on Salmonella biofilm formation. Farm level and animal level Salmonella prevalence was (7.6%, 2.3%) in dairy; (14.6%, 4.7%) in poultry; and (42.6%, 4.4%) in swine farms. The prevalence was 7.2% in diarrheic patients from primary health centers and 2.1% from hospitals. S.Typhimurium (27.6%) was the most frequently isolated serotype, followed by S. Saintpaul (21.7%), S. Virchow (18.4%) and S. Kentucky (6.6%). Salmonella isolation was significantly associated with detection of diarrhea in dairy cattle (p=0.012), and consumption of raw vegetables in humans (OR=1.91, 95% CI=1.29-2.83, χ2=4.74, p=0.025). Drug resistance was more common in dairy farms in Addis Ababa than outside (p=0.009) and overall antimicrobial resistance was more common in animals than in humans. Clonally related genotypes of S.Virchow, S.Typhimurium, S.Kentucky, S.Braendurp and S. Miami were circulating among humans and animals as determined by pulsed-field gel electrophoresis (PFGE). MLST analysis showed 3 novel allele types and 5 novel sequence types among 21 strains examined. The dominant beta-lactamase enzyme was blaTEM type. BlaOXA10 and blaCTX-15 were detected only in a single MDR S. Concord strain. Double mutation in gyrA (Ser83-Phe and Asp87-Gly) as well as parC (Thr57-Ser + Ser80-Ile) subunits of quinolone resistance determining region (QRDR) was the primary mechanism for resistance to quinolones and was detected in all S. Kentucky isolates resistant to both nalidixic acid and ciprofloxacin from animals (n=8) and humans (n=2). Although decreased susceptibility to ciprofloxacin and/or nalidixic acid was observed in some isolates, no mutation in QRDR nor plasmid mediated quinolone resistance (PMQR) genes were detected. Majority of Salmonella ii isolates exhibited robust biofilm formation (89%) and displayed red dry and rough (RDAR) morphotype. Detection of class 1 integron was correlated with expression of multicellular behavior and the extent of MDR. Screening of an ATP-mimetic library, gave a single compound (7955004) capable of significant inhibition of Salmonella enterica and Acinetobacter baumannii biofilm formation. The compound was not bactericidal or bacteriostatic toward S. Typhimurium nor cytotoxic to mammalian cells. GroEL and DeoD were found to be the potential protein-binding targets of the compound as identified by ATP-sepharose affinity matrix. Circulation of clonally related NTS serotypes in food animals and humans, abundance of MDR in isolates from food animals, co-dominance of MDR and multicellular behavior in Salmonella isolates in the study area, increased the risk of spreading resistant Salmonella strains and resistance genes to human population. Integrated surveillance of NTS in humans and animals and implementation of appropriate pathogen control strategy along critical points in food animal production from farm to bench is recommended. The identification of a lead compound with biofilm inhibitory capabilities toward Salmonella provides a potential new avenue of therapeutic intervention against Salmonella and other bacterial pathogens. Further activity guided evaluation of compound 7955004 and its derivatives with the goal of increasing its potency and broadening its spectrum of activity against additional biofilm forming pathogens should be conducted. Key words: Antimicrobial resistance, Biofilm, Non-typhoidal Salmonella, Prevalence, Serotype
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    Phenotypic and Molecular Characterizations of Salmonella Species in Ethiopia
    (Addis Ababa University, 2008-12) Beyene, Getenet; Asrat, Daniel(PhD); Mengistu, Yohannes(PhD)
    Background: Salmonella infections are very common and an important public health problem in many parts of the world. In sub-Saharan Africa there is very little direct data on strain type or antibiotic resistance. Research to date, as well as unpublished reports from different health institutions in Ethiopia, has indicated that salmonellosis is a common problem and the extensive use of the first line drugs has led to the development of multiple drug resistance at a level which could pose a serious problem in the near future. OBJECTIVES: The study was aimed at defining the serovars responsible for Salmonella infection, estimating the level of antibiotic resistance, investigate molecular basis of resistance and observing molecular polymorphism among Salmonella species isolated from children in Ethiopia. MATERIALS AND METHODS: Pediatric patients (n=1225) presenting with diarrhoea or fever from pediatric out patient department of Tikur Anbessa University Hospital, Addis Ababa (n= 825) and Jimma University Hospital, south west Ethiopia (n= 400) were investigated for enteric pathogens during January 2006 to June 2008. Forty eight Salmonella isolates collected in Tikur Anbessa hospital between January, 2004 and December, 2005 from similar age group were analyzed together. Stool specimens were collected for microscopic examination and culture. In addition blood specimens were obtained for culture. Brain Heart Infusion broth was used for blood culture and Selenite F broth enrichment followed by plating on Deoxycholate agar (DCA) and Xylose lysin deoxycholate agar (XLD) were used for stool culture. Identification of Salmonella species was carried out using API-20E, serology with antisera and strain were characterized using multilocus sequence typing (MLST). Based on resistance pattern, site of collection and type of specimen in which the isolate was detected, S. Concord isolates were selected and investigated for plasmid profile, incompatibility grouping, pulsed field gel electrophoresis (PFGE), MLST profile and fliC gene sequencing using standard procedures. In addition, 48 previously collected Salmonella isolates before the commencement of the present study were sero-grouped and serotyped. RESULTS: A total of 463 entropathogens were isolated from 1225 pediatric patients. The isolates were: 65 Salmonella species, 61 Shigella species and 337 parasites. Among the 113 xi Salmonella isolates (65 + 48 previously collected), serogroup C, B, D and E were isolated at a frequency of 78.8%, 11.5%, 8% and 1.8% respectively. Most of the Salmonella isolates were from stool (68%) and the rest were from blood (32%). No isolate was detected from both blood and stool of the same patient. A total of 12 serotypes were identified namely; S. Concord (82), S. Colindale (1), S. Gatow (3), S. Laronchelle (1), S. Garoli (1), S. Colorado (1), S. Typhimurium (7) S. Paratyphi B(2), S. Haifa (1) S. Typhi (2) S. Enteritidis (4), and S. Butantan (2). Eighty nine percent of the group C isolates were S. Concord. S. Concord isolates were highly resistant to ampicillin, trimethoprimsulfamethoxazole, ceftriaxone, amoxicillin, chloramphenicol, gentamicin, and tetracycline. Low resistance rate was observed for nalidixic acid and ofloxacin and there was no resistance to ciprofloxacin by disk diffusion test. However, E-test result indicated the presence of one resistant, one intermediate and twenty two (26.8%) Concord isolates which showed reduced susceptibility to ciprofloxacin. The extended spectrum beta lactamase (ESBL) screening test result showed that 98.8% of S. Concord were positive for ESBL production. Plasmid analysis showed that all characterized S. Concord isolates harbored multiple copies of small and large plasmids. The molecular weight of plasmids varied from less than five to 170 kb with 120, 118 and 95 kb being the most prevalent. Plasmid replicons A/C, I1 and incFI were found in the majority of the isolates. Different plasmid studies indicated that A/C and incFI replicons are associated with multi drug resistance (MDR) Salmonella isolates. A total of 16 pulse field gel electrophoresis (PFGE) profiles were seen among the 23 Concord group and 5 non Concord isolates. Every sequence type (ST) had a unique PFGE profile which indicates that S. Concord in Ethiopia is in an endemic situation, rather than a spread of a clonal type (has many different point sources/reservoirs). The same ST and PFGE types were found in Addis Ababa and in Jimma suggesting movement of infected people/reservoirs between the two cities. Multilocus sequence typing (MLST) analysis showed the presence of a total of seven STs among 58 isolates. ST533, ST534 and ST599 are single locus variants. Because they differ in only one of the seven loci, they are closely related genetically and make a single Concord group. Distantly related serotypes like Gatow and Colindale had sequence types that differ by more than one allele from Concord group. Molecular serotyping using sequencing of the fliC gene was able to differentiate xii between S. Haifa and the S. Concord group of isolates indicating the possibility of its role in molecular serology. For our strain collection, it seems therefore that fliC sequencing can complement MLST for classification and strain differentiation. CONCLUSION AND RECOMMENDATIONS: Salmonellosis in children in these two regions of Ethiopia is mainly due to non-typhoidal salmonellae particularly with S. Concord. This is different from other countries where S. Enteritidis and S. Typhimurium accounted for the majority of salmonellosis. Both phenotypic and genotypic characterization indicated that S. Concord is highly resistant and present in endemic situation in Ethiopia. The presence of many multi-drug resistant strains containing genes for ESBL production and the emergence of reduced susceptibility to ciprofloxacin in this study posed a major concern in the search for efficient antimicrobial therapy of Salmonella infections in the near future. Therefore more comprehensive studies should be designed to trace its source and distribution within the country and to monitor antibiotic resistance pattern over time.
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    Prevalence of Group B Streptococcus Colonization Among Pregnant Women Attending Antenatalclinic of Hawassa Health Center, Hawassa, Ethiopia
    (Addis Ababa University, 2008) Mohammed, Musa; Asrat, Daniel(PhD)
    Background: Group B streptococcus (GBS) or Streptococcus agalactiae are members of the normal flora of the female genital tract. During labor GBS may infect the newborn, leading to neonatal sepsis and meningitis. GBS emerged in the 1970s as one of the most frequent causes of sepsis and meningitis in neonates and young infants. Since the mid-1960s, GBS has become the major cause of bacterial infections in the perinatal period, including bacteraemia, amnionitis, endometritis, and urinary tract infection in pregnant women. Rates of GBS colonization vary widely throughout the world due to differences in laboratory investigation methods, regional variations and racial differences. Report on prevalence of GBS among pregnant women in Ethiopia is very limited. Objectives: The objective of this study was to determine the prevalence of group B Streptococcal (GBS) colonization among pregnant women attending antenatal clinic at Hawassa Health centre, Hawassa Ethiopia and analyze risk factors related to GBS colonization. Methods: A total of 139 pregnant women were screened for GBS colonization between May and June 2010. Standard microbiological methods were used to isolate and identify GBS from vaginal and anorectal swabs obtained from study subjects. Antimicrobial susceptibility test was performed for all GBS isolates according to the criteria of the National Committee for Clinical Laboratory Standards by disk diffusion method. Results: A total of 29 out of 139 pregnant women studied (20.8%) were colonized by GBS. No statistically significant association was observed for GBS colonization with any of sociodemographic characteristics of the study subjects including age, occupation, type of contraceptive used, types of gravida, number of antenatal clinic visits etc. All GBS strains were susceptible to penicillin, ampicillin, vancomycin and gentamicin, Low level of resistance (<60%) were observed against erythromycin, tetracycline, ceftriaxone, chloramphenicol, ciprofloxacin and norfloxacin. Conclusion and recommendations: this study including 139 pregnant women, confirmed the prevalence of GBS colonization to be around 21%. This prevalence was compared with findings reported from developed and developing countries and have reached comparable level. However, further epidemiological investigations should be conducted in different parts of the country in order to know the actual GBS colonization rate in pregnant women and consider implementation of prevention plans using intrapartum antibiotics prophylaxis to prevent early onset GBS-neonatal diseases. Key words: Group B Streptococcus (GBS), risk factors, Antibiotic susceptibility, Ethiopia.
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    Serological and Molecular Characterization of Hepatitis B, C and D Viruses Infections Among Health Professionals in Ras Desta and Tikur Anbessa Hospitals, Addis Ababa, Ethiopia
    (Addis Ababa University, 2008) Yimer, Kedir; Asrat, Daniel(PhD)
    The risks for occupational infection with blood-borne pathogens (HBV, HCV, and HIV) have been a source of concern among health professionals because of their frequent and often substantial exposures to patient blood and body fluids and all of which are associated with significant morbidity and mortality. A cross sectional study was conducted in order to assess the prevalence of HBV, HCV, and HDV infections among HCW’s (n=267) and risk factors associated with these viral infections. After each volunteer study subject has completed a standardized questionnaire, 10 ml of venous blood was collected from each individual for serological and molecular processing. ELISA method was used to detect HBs and HBe antigens, antibodies to HBc, HBs, HDV and HCV in the serum samples. Molecular methods were used to detect HBV DNA and HCV RNA. One hundred and eight (40.4%) of the health professionals use gloves consistently, 221 (82.3%) had at least a one time history of cutaneous exposure to blood ungloved, 165 (61.8%) of health care workers had at least a one time history of cutaneous exposure to any of the body fluids, 162 (60.6%) had splashed blood or body fluids in their faces, 158 (59.2 %) had sustained needle stick injury and 83 (31.1%) sustained sharp injury. The overall prevalence of HBV infection was found to be 51.3% (95% CI: 45-57%) and the infection prevalence increases with age (p<0.01). HBsAg was detected in 9.7 % (95% CI: 6-13.2%) of HCW’s. Absence of vaccination was the only risk factor associated with hepatitis B infection (p=0.001). Though only a single individual had HBeAg (4.5%; 95% CI: 2-7%), HBV DNA was detected by PCR in serum sample from 17 of the 24 subjects (71%). The hepatitis B vaccination rate was found to be 13%. Ninety three percent of individuals who were vaccinated with a single dose of HBs vaccine had achieved protective antibody. ‘Anti-HBc only’ positive cases were detected in 6 (2.2%; 95% CI: 0.004-3.96%) individuals however HBV DNA was not detected in any of the samples tested. HCV infection was detected in 1 (0.37%) study subject. None of the HBsAg positive individuals had marker of HDV infection. Our data suggest that occupational exposures to blood and body fluids occur frequently with low universal precaution practice and vaccination coverage. Hepatitis B infection is widespread and characterized by high level of immunity through natural infection and the presence of continuous horizontal transmission. Absence of vaccination is the only risk factor associated with hepatitis B infection. In this study HCV and HDV infection prevalence is very low. Serologic response rate to a single dose of viii hepatitis B vaccine was much higher than experiences from other countries. HBeAg negative serological status and low viral replication levels characterize chronic hepatitis B virus-infected health professional. ‘Anti-HBc only’ is found in the health professionals but none of the subjects had detectable HBV DNA. This suggests the need to do future study in ‘Anti-HBc only’ case
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    Throat Carriage Rate and Antibiotic Susceptibility Pattern of Beta-Hemolytic Streptococci and Gram Negative Oral Commensals in Children with Rheumatic Heart Disease on Secondary Antibiotic Prophylaxis in Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia
    (Addis Ababa University, 2014-11) Zegeye, Nigus; Asrat, Daniel(PhD); W/Amanuel, Yimtubezinash (PhD)
    Background: Rheumatic fever and rheumatic heart disease remain significant causes of cardiovascular diseases in Ethiopian children. Objectives: This study was conducted to determine the throat carriage rate and antibiotic susceptibility pattern of beta-hemolytic Streptococci and gram negative oral commensal bacteria, such as Neisseria species in order to have a better understanding of their composition and dynamics in children having rheumatic heart disease who received on-going monthly Penicillin G prophylaxis. Methods: Throat swab from 234 children who had rheumatic heart disease and received ongoing secondary prophylaxis was collected and inoculated onto Sheep blood and Modified Thayer-Martin agar plates. The bacterial strains were analyzed by conventional methods as well as advanced mass spectrometry and molecular methods. Antimicrobial susceptibility testing of streptococci was performed by Kirby Bauer disc diffusion method. ASO titer determination was also done for infection or colonization differentiation. Results: Out of 234 participants, 38.03% were referred for possible surgical intervention but only three participants received this treatment. Throat carriage rate of beta-hemolytic streptococci was 23.93 % (56/234). Of these, 4 were S. pyogenes. Streptococcus dysgalactaie subsp. equisimilis possessing Lancefield group A, C and G were isolated. Six different emm gene types with one newly discovered subtype (stGrobn.1) were identified. The Streptococcal glycosyltransferase in strain emm 68.2 (multidrug resistant strain) had N-linked glycosylation carrying a unique HexNAc-deoxyhexose; a novel post-translational modification not previously recognized or studied which indicates it is not only M protein responsible for rheumatic fever disease. All beta- hemolytic Streptococci were susceptible to penicillin except S. agalactaie. Erythromycin and tetracycline resistant S. pyogenes were isolated. Among 234 participants, 29.49% (69) was positive to ASO. Of the positives, 66.67 % (46 / 69) showed increased ASO titers (ASO > 200 units/μL) and the rest 33.3% (23/69) was ASO =200 units/ μL. Children who received antibiotic prophylaxis within two weeks showed significantly lower beta- hemolytic streptococcal throat carriage than 4 weeks of injection (p=0. 004). The isolation rate of gram negative oropharyngeal commensals was 55.1% (129/234). Throat carrier rate of N. meningitidis, N. lactamica, M. catarrhalis, K. denitrificans and K. kingae were 4.27%, 4.27%, 19.66 %, 15.81% and 2.56 % respectively. IX Conclusion: Characterization of carrier strains and increased ASO titer in rheumatic heart disease is likely to elucidate the significance and mechanisms for carriage and drug resistance during on-going penicillin G monthly prophylaxis. The throat carriage rate of gram negative commensals seems affected by on-going penicillin G prophylaxis. Recommendation: The current schedule benzathine penicillin prophylaxis injection should be revised (changing schedule of benzathine penicillin G prophylaxis from four to two weeks). Treatment intervention has to be established to provide services for those who need repair or replacement of their damaged heart valves. Penicillin failure to clear pathogenic streptococci needs further investigations. Key words: Group A streptococcus, beta-hemolytic streptococci, rheumatic heart disease, rheumatic fever, antibiotic prophylaxis, susceptibility pattern, emm type, protein profile, gram negative oral commensal, Ethiopia