Non-typhoidal Salmonella serotypes, antimicrobial resistance and co-infection with parasites among patients with diarrhea and other gastrointestinal complaints in Addis Ababa, Ethiopia

Abstract

BackgroundNon-typhoidal Salmonella (NTS) is an important public health problem worldwide. Consumption of animal-derived food products and direct and/or indirect contact with animals are the major routes of acquiring infection with NTS. Published information, particularly on the serotype distribution of NTS among human patients with gastroenteritis and associated risk factors, is scarce in Ethiopia. This study investigated the prevalence, risk factors, serotype distribution and antimicrobial susceptibility of Salmonella species among diarrheic out-patients attending health centers in Addis Ababa and patients with various gastrointestinal complaints at Tikur Anbessa Specialized Hospital (TASH).MethodsStool samples were cultured for Salmonella species according to the WHO Global Foodborne Infections Network laboratory protocol. Salmonella serotyping was conducted using slide agglutination and microplate agglutination techniques. Antibiotic susceptibility testing was performed using the disk diffusion method according to Clinical and Laboratory Standards Institute guidelines.ResultsA total of 59 (6.2 %) stool samples, out of 957 were culture positive for Salmonella species. Fifty-five (7.2 %) of 765 diarrheic patients from health centers and 4 (2.1 %) of 192 patients from TASH were culture positive for Salmonella species. Multivariable logistic regression analysis after adjusting for all other variables revealed statistically significant association of Salmonella infection with consumption of raw vegetables (OR = 1.91, 95 % CI = 1.29–2.83, χ2 = 4.74, p = 0.025) and symptom of watery diarrhea (OR = 3.3, 95 % CI = 1.23–8.88, χ2 = 10.54, p = 0.005). Eleven serotypes were detected, and the most prominent were S. Typhimurium (37.3 %), S. Virchow (34 %), and S. Kottbus (10.2 %). Other serotypes were S. Miami, S. Kentucky, S. Newport, S. Enteritidis, S. Braenderup, S. Saintpaul, S. Concord and S. V:ROUGH-O. Resistance to three or more antimicrobials was detected in 27 (40.3 %) of the isolates. Resistance to five or more antimicrobials was detected in 17 (25.4 %). Resistance to individual antimicrobials was found at varying proportions: streptomycin (50; 74.6 %), nitrofurantoin (27; 40.3 %), sulfisoxazole (26; 38.8 %), kanamycin (23; 34.3 %), cephalothin (12; 17.9 %), and ampicillin (11; 16.4 %) respectively. Two S. Kentucky, one S. Typhimurium and one S. Concord isolates were multi-drug resistant to more than 10 antimicrobials.ConclusionsThe study demonstrated significant association of Salmonella infection with consumption of raw vegetables. There was no significant association of Salmonella infection with co-occurring parasites. The study also showed the dominance of S. Typhimurium and S. Virchow in primary health care units. Overall, prevalence of MDR was low compared to previous studies. Although their proportion was low, S. Kentucky and S. Concord demonstrated wider spectrum of MDR. Continuous monitoring of circulating serotypes, antimicrobial resistance profile and characterization on molecular resistance determinants...

Detection of Non-Typhoidal Salmonella Gastroenteritis in a Tertiary Children’s Hospital in China

“…An alarming increase in the antibiotic resistance by NTS was reported elsewhere (11,12). In our study, 54.3% of our isolates were found to be resistant to nalidixic acid, which is lower than that reported from India (77%) (22), Southwest China (66.7%) (27), and higher than that reported from Congo (4.3%) (33), Iraq (45.5%) (23), Ethiopia (23.9%) (34), and Iran (31.5%) (17). Among the NTS isolated from stool samples, Nalidixic acid was predominant among our NTS, (64.8%) which was very much higher than that reported from Kenya (6%) (16).…”

“…Distribution of Non-Typhoidal Salmonella Species a We found that antibiotic resistance by NTS towards nalidixic acid was significantly higher than other tested antibiotics (ANOVA, F = 0.23; P < 0.05).Of the 38 iNTS isolates, the majority of the isolates were resistant to ciprofloxacin (19, 50%) followed by cefotaxime (17, 44.7%), gentamicin(16, 42.1%), nalidixic acid (15, 39.5%), amoxicillin(13,34.2%), ampicillin(12,31.6%), cotrimoxazole (10, 26.3%), amikacin (9, 23.7%) and chloramphenicol(8, 21.1%) …”

Genetic markers associated with resistance to beta-lactam and quinolone antimicrobials in non-typhoidal Salmonella isolates from humans and animals in central Ethiopia

“…A strain of serotype V: rough-O;-:- that was susceptible to nalidixic acid but intermediately resistant to ciprofloxacin had single substitution of Ser463-Ala on gyr B gene. Over half of the quinolone resistant isolates in the current study 17 (58.6%) were also resistant to at least one of the beta-lactam antimicrobials (Table 5) and all S. Kentucky isolates resistant to nalidixic acid and ciprofloxacin were also shown to be MDR to several antimicrobials in our previous works [27, 28]. No mutation was detected in par E gene in any of the isolates examined in the current study.…”

Serovars and antimicrobial resistance of non‐typhoidal Salmonella isolated from non‐diarrhoeic dogs in Grenada, West Indies

“…The inhibition zone sizes were interpreted based on CLSI guidelines. Escherichia coli ATCC 25922 was used as quality control strain (Eguale et al 2015).…”