Salmonella isolated from chicken carcasses from a slaughterhouse in the state of Mato Grosso, Brazil: antibiotic resistance profile, serotyping, and characterization by repetitive sequence-based PCR system

Abstract

Salmonella is one of the major causative agents of foodborne infections. Salmonellosis becomes more dangerous when strains resistant to several antibiotics are found in food, especially in chicken, one of the primary transmission vehicles of this pathogen for humans. The present study aimed to estimate the occurrence of Salmonella in chicken carcasses from the state of Mato Grosso, Brazil, as well as determine the antibiotic resistance profile and genotypic characteristic of multi-drug resistant (MDR) isolates. During a 15-month period, from 01/2014 to 05/2015, 850 samples of chilled fresh chicken carcasses were sampled from a slaughterhouse and submitted to Salmonella determinations according to the ISO-6579/2002 method, serotyping and multiplex PCR. The disc diffusion test was applied for 17 antibiotics, according to CLSI (2014). Five isolates were genotyped by repetitive sequence-based PCR using the semi-automated DiversiLab (bioMérieux®) system. The occurrence of Salmonella in chicken carcasses was of 3.7% (31/850), with only 4 strains (12.9%) presenting as MDR, and 6 strains (19.35%) displaying ESBL. The predominant serovars were Salmonella Infantis (35.4%, 11/31), and S. Abony (25.8%, 8/31), followed by serovars S. Agona (12.9%, 4/31), S. Schwarzengrund (9.7%, 3/31), S. Anatum and Salmonella enterica O:4,5 (6.5%, 2/31), and only one Salmonella enterica O:6,7 strain (3.2%, 1/31). All isolates were resistant to one to 5 classes of antibiotics in decreasing order: folate pathway inhibitors, β-lactams (cephalosporins, penicillin, monobactams), tetracyclines, chloramphenicol, and gentamicin. However, strains sensitive to florfenicol, streptomycin, nalidixic acid, ciprofloxacin, enrofloxacin, and nitrofurantoin were also found in this study. Genotyping revealed 98 to 99% homology between 3 Salmonella strains, which displayed high phenotypic resistance similarity to β-lactams and folate pathway inhibitors. Detection of MDR non-typhoid Salmonella in chicken slaughterhouses with quality assurance systems such as Hazard Analysis and Critical Points and Implemented Good Manufacturing Practices is a concern, reinforcing the need for constant monitoring of these pathogens, with the purpose of safeguarding the safety of their products.

Genomic Epidemiology of Salmonella Infantis in Ecuador: From Poultry Farms to Human Infections

“…This issue is especially evident in S . Infantis, as already been seen in Ecuador ( 7 , 8 ) and other countries of the region ( 63 – 65 ). Although in a lower extent, this feature has also been reported in Europe where high rates of MDR (up to 85%) are reported in S .…”

Detection and quantification of Salmonella spp. in poultry slaughterhouses of southern Brazil

“…It is important to highlight that we detected Salmonella in all stages of the process, except carcasses after pre-chiller. Carcass contamination during slaughtering process has already been described, including in Brazilian plants [15,25,26]. Although, carcass contamination varied along the slaughtering process and we could not establish any pattern of variation.…”

Prevalence of Salmonella Isolates and Their Distribution Based on Whole-Genome Sequence in a Chicken Slaughterhouse in Jiangsu, China

“…The prevalence rates of Salmonella were 30.0 and 9.4% in two different chicken slaughterhouses, respectively, in a study from South Korea (23), while the prevalence rate was 11.1% in a chicken slaughterhouse in the northeast of Algeria (24). A study from Brazil demonstrated that the prevalence of Salmonella was only 3.6% in a chicken slaughterhouse (25). In China, the isolation rate of Salmonella was 12.7% in chickens in Shandong province (13), while no Salmonella was detected in a chicken slaughterhouse in Sichuan province (26).…”