Prevalence and clonal relationship of ESBL-producing Salmonella strains from humans and poultry in northeastern Algeria

Abstract

BackgroundThe aims of this study were to investigate Salmonella contamination in broiler chicken farms and slaughterhouses, to assess the antibiotic resistance profile in avian and human Salmonella isolates, and to evaluate the relationship between avian and human Extended Spectrum β-Lactamase (ESBL)-producing isolates. Salmonella was screened in different sample matrices collected at thirty-two chicken farms and five slaughterhouses. The human isolates were recovered from clinical specimens at the University Teaching Hospital of Constantine (UTH). All suspected colonies were confirmed by MALDI-TOF (Matrix Assisted Laser Desorption Ionization Time OF light) and serotyped. Susceptibility testing against 13 antibiotics including, amoxicillin/clavulanic acid, ticarcillin, cefoxitin, cefotaxime, aztreonam, imipenem, ertapenem, gentamicin, amikacin, ciprofloxacin, colistin, trimethoprim/sulfamethoxazole and fosfomycin, was performed using the disk diffusion method on Mueller-Hinton agar. ESBL-production was screened by the double-disk synergy test and confirmed by molecular characterization using PCR (polymerase chain reaction) amplification and sequencing of ESBL encoding genes. Clonality of the avian and human strains was performed using the Multi Locus Sequencing Typing method (MLST).ResultsForty-five isolated avian Salmonella strains and 37 human collected ones were studied. Five S. enterica serotypes were found in avian isolates (mainly Kentucky) and 9 from human ones (essentially Infantis). 51.11% and 26.6% of the avian isolates were resistant to ciprofloxacin and cefotaxime, respectively, whereas human isolates were less resistant to these antibiotics (13.5% to ciprofloxacin and 16.2% to cefotaxime). Eighteen (12 avian and 6 human) strains were found to produce ESBLs, which were identified as bla CTX-M-1 (n = 12), bla CTX-M-15 (n = 5) and bla TEM group (n = 8). Interestingly, seven of the ESBL-producing strains (5 avian and 2 human) were of the same ST (ST15) and clustered together, suggesting a common origin.ConclusionThe results of the combined phenotypic and genotypic analysis found in this study suggest a close relationship between human and avian strains and support the hypothesis that poultry production may play a role in the spread of multidrug-resistant Salmonella in the human community within the study region.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-017-1050-3) contains supplementary material, which is available to authorized users.

Serotype diversity and slaughterhouse-level risk factors related to Salmonella contamination on poultry carcasses in Algiers

“…The authors suggest that the preponderance of S. Heidelberg in turkey meat reflects its great presence in flocks. On the other hand, previous national reports on chicken at both farm and slaughterhouse levels, were found only farm samples to be S. Heidelberg -contaminated [21,46]. The isolation of this serotype from slaughterhouse samples could depend on its initial pre-slaughter load in live birds.…”

“…S. Kentucky, S. Enteritidis, S. Typhimurium, S. Heidelberg and S. Virginia were common to the two poultry species. Except for S. Typhimurium, the same serotypes were recently isolated in northeastern Algeria in broiler breedings and slaughterhouses with predominance of S. Kentucky [46]. In east part of Algeria, S. Kentucky was isolated from feces on laying-hen flocks [22] and found to be the most prevalent in dairy cattle breedings (unpublished data) while Nouichi et al [47] registered a 13.8% Salmonella-contaminated ovine and bovine carcasses at Algiers' slaughterhouses.…”

An Algerian perspective on non-typhoidal Salmonella infection

“…Of 27 poultry houses, 34% were found to be contaminated with Salmonella; the main NTS serotypes isolated were S. Kentucky and S. Heidelberg, then S. Enteritidis, S. Virginia and S. Newport (Table 1) [33]. These studies conducted on NTS infection in Algeria, provide evidence for the presence of highly drug resistant serotypes.…”

“…To date, these studies have been reported information from various cities in Algeria, including Algiers, Boumerdes, TiziOuzou, Bouira, Bejaia, Constantine, Batna, Annaba and El Taref (Figure 1) and are summarized below [10,[28][29][30][31][32][33].…”

Screening for the Extended Spectrum Beta Lactamases Among Salmonella Spp. Isolated From Broiler Chicken in Egypt.

“…Out of 46 Salmonella isolates, only 11 (23.9%) isolates were grown on MacConkey agar supplemented by cefotaxime 1 mg⁄ L, of which, only 54.4% isolates were positive with double disc synergy test. In parallel, Djeffal et al (2017) documented that 26.5% of Salmonella isolates were considered as ESBL producers, while, Noda et al (2015) reported higher incidence (45.6%), based on resistance to Cefotaxime. The increased incidence of antibiotic resistance in Salmonellae has resulted from the inappropriate use of antibiotics including cephalosporins in chicken farms (Okeke et al, 2005).…”