Browsing by Author "Njeru, John Mwaniki"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Molecule characterization of antibiotic resistance in SHIGELLA species isolated from diarrhoeic stool samples of patients attending Kwale District hospital, Kenya
    (2012-03-20) Njeru, John Mwaniki
    Acute diarrheal diseases are a major cause of high morbidity and mortality and shigellosis is a major cause of this problem. Shigella boydii, S. sonnei, S. dysenteriae and 8.flexneri are implicated in causing shigellosis. Shigellosis caused by multidrug-resistant (MDR) Shigella strains constitutes an increasing problem due to limited therapeutic options. In Kenya, shigellosis is mainly due to S. jlexneri. Despite the observed increase in resistance among Shigella strains to commonly used antibiotics, data on the occurrence and the role of plasmids and integrons in the emergence and spread of MDR Shigella in Kenya is scanty. This study used molecular methods to analyse Shigella plasmids and class 1 and 2 integrons known to harbor resistance to antibiotics. Stool samples from diarrheal patients attending K wale District hospital in Kenya were cultured for Shigella and antimicrobial susceptibility tests performed. Conjugations, integrons and plasmid profile analysis were carried out to determine the molecular basis for transmissible drug resistance in Shigella. An overall Shigella incidence rate of 8.1 % was found. The age group 1-5 years had the highest incidence rate at 18.3% and statistically significant differences was shown between incidence of Shigella and age (x.2 = 8.684, df = 4, p = 0.003). As high as 96.6% of the Shigella isolates had resistance to one or more antibiotics with 86.2% showing MDR characteristics. A total of 15 MDR profiles were identified with the sulfamethoxazole-trimethoprim(Sxt), streptomycin(Str), ampicillin(Amp) and tetracycline(Tet) being the most common resistance pattern at 53%. All the isolates were susceptible to ciprofloxacin and cephalosporin antibiotics tested. 96.6% of the isolates screened contained one or more plasm ids ranging from 1-6. Majority were small plasmids comprising of 1-2kb, 3-4kb and 5-9kb occurring in 86.9%, 78.3% and 47.5% of the isolates respectively. Species specific plasmids of 3.2kb, 9.0kb and 3.8kb plasm ids were found in S. flexneri, S. dysenteriae and S. sonnei respectively. The large plasm ids and middle range plasmids were found in 34.5% and 79.3% of the isolates respectively. In all species, no precise correlations were found between specific plasmid profiles and antibiotic resistance patterns but significant statistical associations were shown between harboring middle range plasm ids (48kb and 80kb) and MDR phenotypes among the isolates (Fishers Exact Test, p=0.002). Of all MDR Shigella isolates, 32% were able to transfer plasmids to E. coli J53 strain. These plasm ids specified resistance to Sxt, Amp, Str and Tet. Class 1 and 2 integrons were detected in 6.9% and 82.8% of the isolates respectively and significant statistical association between carriage of class 2 integron and MDR phenotype shown(Fisher's Exact Test, p = 0.0004). None of the non-MDR strains carried integrons. A statistical association was shown between presence of class 2 integron and the resistance profile, Sxt, Amp, Str, Tet (Fisher's Exact Test, p = 0.0001). 28.5%, of Class 2 integrons were self transferable. This study showed that shigellosis is endemic at Kwale and that children were at a higher risk of shigellosis. The findings also show that Sxt, Str, Amp may not be used empirically as the first line drugs in treatment of shigellosis in the region. Self transferable plasmids and class 2 integrons carrying drug resistance gene cassettes are widespread among MDR Shigella spp indicating the active role of these elements in the spread of multidrug resistance. The study recommends continuous surveillance of drug resistance pattern changes in Shigella for consideration in treatment of shigellosis and adoption of ciprofloxacin and/or cephalosporin antibiotics as first line therapeutic options for empirical treatment of shigellosis.
  • Thumbnail Image
    Item
    Prevalence, Associated Risk Factors and Antibiotic Susceptibility Patterns of Common Diarrheagenic Bacteria Isolated from Food Handler Populations in Nairobi, Kenya
    (asiapacificpublishers, 2025-04) Gitau, Daniel Karuoya; Maingi, John M.; Gitau , George; Muasya, Daniel; Karugu , Mercy; Kiminda, Ernestina; Njeru, John Mwaniki
    Background:Diarrheal disease is estimated to cause 29% of illness among adults and is also the major cause of illness and hospitalization for children under 5 years of age. Despite the high cases of food borne illness, there is still low reporting, diagnosis and recording of infection rates. Food handlers play a significant role in food borne pathogens transmission due to their direct contact with food and drinks. This study aimed at determining the prevalence, associated risk factors and antibiotic susceptibility profiles of common diarrheagenic bacterial pathogens among food handler populations in Nairobi.Materials and Methods:A cross-sectional study was conducted by systematically enrolling consenting food handlers working in the hospitality industry in Nairobi into the study. Self-reported data focusing on Water, Sanitation and Hygiene (WASH)-related behaviors of the participants was collected through a structured, closed-ended questionnaire. Stool samples were obtained and bacteriological analysis performed using conventional stool culture methods. The recovered bacterial isolates thereafter underwent Antibiotic Susceptibility Testing (AST) using the disk diffusion method to determine their resistance profiles. To assess the factors associated with antimicrobialresistance, Poisson regression modeling (univariate and multivariate) was used on the count outcome (number of antimicrobials to which a sample was resistant).Results:A total of 231 isolates were confirmed as the pathogens of interest after biochemical testing: Escherichiacoli(178/885), Klebsiellapneumoniae (47/885), Salmonellaspp (5/885) and Shigella(1/885). Almost all the recovered isolates showed resistance to erythromycin (97%) while about 81% exhibited resistance to amoxicillin-clavulanic acid.There was intermediate resistance seen against cefotaxime (40%), cefepime (33%), cefuroxime (53.75%) and gentamicin (27%). Low level of resistance was found against meropenem (1%), ciprofloxacin (10%) and chloramphenicol (9%). Of the E. coliisolates obtained, 41 (23%) were multi drug resistant and 2 (1.12%) were both Multi Drug Resistant and Pan Drug Resistant (PDR). Only 1 Klebsiella sppisolate was MDR. None of the Salmonella sppand Shigella sppwas found to be Multi-Drug Resistant. Regular handwashingwas found to be the most significant risk factor for infection with a pathogenic bacteria (p<0.05: 95% CI: [-0.339-0.127]). Food handlers who practiced regular handwashing had significantly lower antimicrobial resistance counts based on their incident rate ratios (IRRs) (IRR = 0.85, p = 0.029). Conversely, wearing hairnets (IRR = 2.55, p < 0.001) and working in informal eateries (IRR = 1.51, p = 0.005) or middle-level restaurants (IRR = 1.43, p = 0.008) were associated with higher resistance counts.Conclusion:Afairly high prevalence of diarrheagenic bacterial pathogens (26%) was found among the food handler population. There was also notably high levels of antibiotic resistance to commonly used drugs for diarrhea management, with medium and high levels of drug resistance to common first line drugs like erythromycin and amoxicillin-clavulanic acid being observed. Efforts should be made to improve access to clean water for both personal and hotel use for the sake of proper food hygiene practices such as handwashing. Sensitization for increased awareness on the importance of proper handwashing practices should also be done more regularly at the workplaces. All workers should also be medically examined appropriately and regularly before certification and advised to seek proper treatment in case of gastrointestinal illness to ensure proper administration of antibiotics for treatment to reduce potential cases of drug resistance.