Medical Microbiology

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Browsing Medical Microbiology by Subject "Antimicrobial susceptibility"

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    Enteric Pathogens and Antimicrobial Susceptibility Profile Among Pediatric Patients with Diarrhea: A Cross Sectional Study in Selected Health Facilities, Addis Ababa, Ethiopia
    (Addis Ababa University, 2017-06) Ayenew, Zeleke; Gebre-Selassie, Solomon(PhD); Abebe, Tamrat(PhD)
    Background: Diarrheal disease remains a major public health problem in developing countries including Ethiopia. The current study was designed to isolate medically important enteric pathogens and assess the antimicrobial susceptibility testing of bacteria causing diarrhea in pediatrics for those antibiotics were prescribing in Integrated Management of Childhood illness (IMCI). Methods: Across-sectional study to determine enteric pathogenic microorganisms that cause diarrhea and antimicrobial susceptibility profile was carried out in selected health facilities of Addis Ababa, Ethiopia from November 2016 to May 2017. Stool specimens from pediatric patients aged 0-14 years were collected randomly from two health centers and one specialized hospital to identify enteric pathogens. Antimicrobial susceptibility tests were performed on all bacterial isolates using the Kirby-Bauer disc diffusion method. Results: In this study, the major etiologic agents of diarrhea in pediatrics were intestinal parasites and bacterial infection accounting for 93(32%) and 42(14.5%) respectively. Out of 290 study patients complain of diarrhea examined, E.histolytica/dispar 75(25.8%), G.lamblia 13(4.5%) and H.nana 4(1.4%) were identified. The majority of bacterial enteropahogens isolated in the study were Shigella spp 22(7.6%) followed by enterohemorrgic E.coli O157:H7 13(4.5%), Salmonella spp 7(2.4%). The overall co-infection rate between parasite-parasite, parasite-bacteria and bacteria-bacteria was observed in 12(4.1%) children. All the bacterial isolates from diarrheal patients were 100% susceptible to meropenem, cefepime, azithromycin and showed antimicrobial resistance to ampicillin, Augmentin, trimethoprim-sulphamethoxazole and ciprfloxacillin. Salmonella spp showed resistance to trimethoprim-sulphamethoxazole and chloramphenicol, 42.9% and 14.3% respectively. Another enteric bacteria Shigella spp were resistant to 77.3%ampicillin, 68.2% trimethoprim-sulphamethoxazole and 36.4%Augmentin whereas E.coliO157:H7 resistance anti-biogram showed 69.2%ampicillin,46.1% trimethoprim-sulphamethoxazole,38.5%Augmentin, 23.1%ciprfloxacillin and Amikacin, ceftriaxone and gentamycin were resistant with the same rate of 15.4%.. Conclusion: The results showed that E.histolytica, G.lamblia and H.nana and bacterial isolates Salmonella spp, enterohemorrhagic E.coli O157:H7, Shigella spp were the most frequently isolated pathogens in Children. The most frequently prescribing drugs ampicillin, amoxicillin+clavulic acid and trimethoprim-sulphamethoxazole showed high resistance for Salmonella and Shigella isolates in the study. It was found that ciprofloxacin was the best drug of choice for the treatment of diarrhea caused by Salmonella and Shigella. Chloramphenicol was a drug of choice for the treatment of shigellosis. So it calls more attention to conduct extensive continuous surveillance to revise and update the prescribing policy in Integrated Management of Childhood illness and Clinicians should rely on stool culture and antimicrobial susceptibility testing. Key words: Enteric pathogens, diarrhea, antimicrobial susceptibility, pediatrics, Addis Ababa, Ethiopia
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    Extended-Spectrum β-Lactamase and Carbapenemase producing Escherichia coli O157:H7 among diarrheic patients in Shashemene, west Arsi, Ethiopia
    (Addis Ababa University, 2023-06) Ayalneh,Shimelis Teshome; Abegaz,Woldaregay Erku (Assoc. Prof.); Gebreselassie,Solomon (Assoc. Prof.); Teferi,Mekonnen(Dr.); Beshah,Biruk Yeshitila(MSc, Ph.D. candidate)
    Background: Escherichia coli (E. coli) O157:H7 has been found in various sources across the globe, and until recently, it was uncommon for this pathogen to produce Extended Spectrum β-Lactamase (ESBL) and Carbapenemase. However, recent reports from different regions have shown that ESBL-producing E. coli O157:H7 is becoming more prevalent. In Ethiopia, while there is sufficient knowledge about the epidemiology of E. coli O157:H7 in the country's different food supply chains, there is a lack of information regarding the extent of disease caused by this pathogen and its production of ESBL and Carbapenemase. Objectives: To isolate E. coli O157:H7, determine its antimicrobial susceptibility profiles, characterize its ESBL and Carbapenemase production from stool specimens collected among diarrheic patients and explore the association of E. coli O157:H7 infection with demographic and clinical features of diarrheal patients in Shashemene, west Arsi, Ethiopia. Methods: A total of 423 study participants were included from July 1, 2022, to November 25, 2022, in this prospective healthcare facility-based cross-sectional study among all patients with diarrhea. The bacterial pathogen was isolated and identified by colony characteristics, Gram stain, and standard biochemical tests using API 20E as well as utilization of sorbitol and serotyping by antisera for O157 antigen. Each identified isolate was screened and tested for ESBL and Carbapenemase production phenotypical and further characterized at the molecular level for 2 Carbapenemase (blaNDM, blaKPC) and 3 ESBL coding gens (blaCTX-M, blaTEM, and blaSHV). The data were entered into SPSS version 26.0 software for analysis. Bi-variant and multi-variant analyses Were employed using a logistic regression model for further analysis and were interpreted based on the odds ratio and level of statisticasignificance at a p-value <0.05. Result: Upon laboratory investigation, E. coli O157:H7 strain was found in 38/423 (9%) study participants from this majority of the participants [262 (61.9%)] were males with a 1.6:1 male: female ratio and 81(19.1%) of the participants were less than five years old and 14 (3.3%) of patients were elders aged above 55 years. Living in urban area, having domestic animal and having ≥5 family size were significantly associated with E. coli O157:H7 cases. High antimicrobial resistance was observed on Ampicillin [38, (100%)] followed by Amoxicillin with clavulanic acid [34, (89.5%)]. However, all isolates were sensitive to ciprofloxacin. Twenty-seven (71.1%) and 12 (31.6%) isolates were phenotypically confirmed to be ESBL and carbapenemase producers, respectively. The genotypic testing revealed that the most abundantly found ESBL genes were blaTEM group 15 (79%) followed by blaCTX-M group 12 (63%) and blaSHV group 2(10%). Additionally, from the 12 carbapenemase-positive isolates, 8 (66.6%) were confirmed to have the blaKPC group gene and none of the isolates were positive for blaNDM group. Conclusion: The E. coli O157:H7 isolates from this study exhibited a high level of resistance to some of the antimicrobials tested. The magnitude of ESBL and Carbapenemase production among these isolates was found to be high. High resistance of Ampicillin and Amoxicillin/Clavulanic acid was observed among ESBL, and carbapenemase- producing isolates and Ciprofloxacin was found to be the most effective drug against both ESBL producers and non- producers. blaTEM group gene was the most abundant ESBL coding gene found and blaKPC group gene was the only gene found in our isolates that code for Carbapenamese.
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    Prevalence and Riskfactors of Pneumococcal Colonization of the Nasopharynx Among Children Attending Kindergarten, Bahir Dar, North West Ethiopia
    (Addis Ababa University, 2015-04) Bereded, Fetlework; Abebe, Tamrat(PhD); Mihret, Adane(PhD)
    Background: One of the most important potential pathogens found in the microflora of the nasopharynx is Streptococcus pneumoniae. S. pneumoniae (pneumococceus) is a major cause of disease, ranging from uncomplicated respiratory tract infections to severe invasive pneumococcal disease (IPD). Objective: The aim of this study was to determine the prevalence of Streptococcus pneumoniae carriage, antimicrobial resistance pattern, and risk factors of pneumococcal colonization of the nasopharynx among children <6 years of age attending kindergartens in Bahir Dar, North West Ethiopia. Methods: A cross-sectional study was conducted from February 2014 to June 2014 in Bahir Dar, Ethiopia. Convenient sampling technique was used to collect the sample. A total of 239 healthy children were enrolled from four governmental and three private kindergartens. A calcium alginate tipped swab on a flexible aluminium shaft was used to collect nasal swab.Standard techniques of culture on blood agar were used to identify S. pneumoniae.The antibiotic susceptibilities of isolates assessed by the disc diffusion method. Data was analyzed using the SPSS version 20.0.Chi-squire tests were used for analysis was used to determine demographic characteristics and prevalence of each isolated organism. A p-value of <0.05 was regarded as statistically significant. Result: The overall carriage prevalence of Streptococcus pneumoniae was 44.8% (n=107) and crowded living (AOR = 0.459; CI, 0.570-2.439), earlier antibiotic use within 2-4weeks (AOR = 8.004 CI, 1136- 56.409), and presence of siblings < 5 years old at home (AOR = 0.467; CI, 0.234-0.933) were associated with pneumococcal carriage. Pneumococcal carriage was not associated with sex, family size, breast-feeding. Six (5.6%) S. pneumoniae isolates were resistant to ceftriaxone, 9 (8.4%) to chloramphenicol, 47 (43.9%) to trimethoprim-sulfamethoxazole (SXT), 17 (15.9%) to erythromycin, 10(9.3%) to penicillin and 24(22.4%) to tetracycline. Ninty three (86.9) S. pneumoniae isolates were susceptible to Ceftriaxone 93(86.9%) and 95(88.8%) were susceptible to Chloramphenicol. Conclusions: Colonization of the nasopharynx in children attending kindergartens in Bahir Dar was high. Half of the isolates of S. pneumoniae were resistant to trimethoprim-sulfamethoxazole (SXT). Key words: Nasopharyngeal carriage; S. pneumoniae; Antimicrobial susceptibility; Children; Ethiopia