Background and Aim: Enterococcus is a commensal bacteria found in humans and animals, which can cause human nosocomial infections. One of the most contaminated enterococcal sources is poultry meat. Therefore, this study estimated the prevalence and antimicrobial resistance (AMR) profile of Enterococcus from chickens and their meat products at local slaughterhouses in Nakhon Ratchasima Province, Thailand. Materials and Methods: From January 2021 to March 2022, 558 samples from 279 cloacal swabs and breast meat were collected from 31 local slaughterhouses in the area. Then, the samples were screened for Enterococcus using modified de Man, Rogosa, and Sharpe agar. Next, selected Gram-positive, catalase-negative, and cocci-shaped colonies were investigated for enterococcal confirmation using Enterococcosel Agar (EA). We also cultivated the samples directly on EA. However, the disk diffusion method was used to investigate positive Enterococcus resistance profiles to 16 antimicrobial agents. Finally, selected phenotypic multidrug-resistant (MDR) Enterococcus isolates were further assessed to identify AMR genes by polymerase chain reaction. Results: Investigations showed that the prevalence of Enterococcus isolates from the chicken cloacal swabs and meat samples were 29.75% (83/279) and 28.32% (78/279), respectively. Most Enterococcus positive isolates were resistant to colistin, followed by cefoxitin, cephalexin, and streptomycin. These isolates also showed a prevalence of MDR species (65.22%; 105/161) and 66 patterns. Furthermore, selected MDR Enterococcus (MDRE) from cloacal swabs and breast meat were positive for the resistant extended-spectrum beta-lactamase TEM genes at 71.43% (20/28) and 78.26% (18/23), respectively, whereas other AMR genes detected in the selected MDR enterococci from the cloacal swabs and breast meat were beta-lactamase TEM (blaTEM [0%, 1.96%]), Class 1 integrase (intI1 [14.28%, 0%]), colistin (mrc–1 [3.57%, 0%]), and vancomycin (vanA [14.28%, 0%]). Conclusion: This study indicated that phenotypic MDRE correlated with extended-spectrum beta-lactamase TEM gene presence, leading to an AMR reservoir that can be transferred to other bacteria.

Enterococcus is a commensal bacteria found in humans and animals, which can cause human nosocomial infections. One of the most contaminated enterococcal sources is poultry meat. Therefore, this study examined the prevalence and antimicrobial resistance (AMR) profile of Enterococcus from chickens and their meat products at local slaughterhouses in Nakhon Ratchasima Province, Thailand. Between January 2021 and March 2022, 558 samples from 279 cloacal swabs and breast meat were collected from 31 local slaughterhouses. Then, the samples were screened for Enterococcus using modified de Man, Rogosa, and Sharpe agar. Next, selected Gram-positive, catalase-negative, and cocci-shaped colonies were investigated for enterococcal confirmation using Enterococcosel Agar. However, the disk diffusion method investigated positive Enterococcus resistance profiles to 16 antimicrobial agents. Finally, selected phenotypic multidrug-resistant (MDR) Enterococcus isolates were further assessed to identify AMR genes by polymerase chain reaction. Investigations showed that although the prevalence of Enterococcus isolates from the chicken cloacal swabs and meat samples was 28.85% (161/558), most Enterococcus isolates were resistant to colistin, followed by cefoxitin, cephalexin, and streptomycin. These isolates also showed MDR prevalence (65.22%; 105/161) and 66 patterns. Furthermore, selected MDR Enterococcus (MDRE) from cloacal swabs and meat were positive for the resistant extended-spectrum beta-lactamase TEM (ESBL-TEM) genes at 71.43% (20/28) and 78.26% (18/23), respectively, whereas other AMR genes detected in the selected MDR enterococci from the cloacal swabs and meat were beta-lactamase TEM [blaTEM (0%, 1.96%)], class 1 integrase [intI1 (14.28%, 0%)], colistin [mrc–1 (3.57%, 0%)], and vancomycin [vanA (14.28%, 0%)]. This study indicated that phenotypic MDRE correlated with ESBL-TEM gene presence, leading to an AMR reservoir that can be transferred to other bacteria.

Enterococcus is a commensal bacteria found in humans and animals, which can cause human nosocomial infections. One of the most contaminated enterococcal sources is poultry meat. Therefore, this study examined the prevalence and antimicrobial resistance (AMR) profile of Enterococcus from chickens and their meat products at local slaughterhouses in Nakhon Ratchasima Province, Thailand. Between January 2021 and March 2022, 558 samples from 279 cloacal swabs and breast meat were collected from 31 local slaughterhouses. Then, the samples were screened for Enterococcus using modified de Man, Rogosa, and Sharpe agar. Next, selected Gram-positive, catalase-negative, and cocci-shaped colonies were investigated for enterococcal confirmation using Enterococcosel Agar. However, the disk diffusion method investigated positive Enterococcus resistance profiles to 16 antimicrobial agents. Finally, selected phenotypic multidrug-resistant (MDR) Enterococcus isolates were further assessed to identify AMR genes by polymerase chain reaction. Investigations showed that although the prevalence of Enterococcus isolates from the chicken cloacal swabs and meat samples was 28.85% (161/558), most Enterococcus isolates were resistant to colistin, followed by cefoxitin, cephalexin, and streptomycin. These isolates also showed MDR prevalence (65.22%; 105/161) and 66 patterns. Furthermore, selected MDR Enterococcus (MDRE) from cloacal swabs and meat were positive for the resistant extended-spectrum beta-lactamase TEM (ESBL-TEM) genes at 71.43% (20/28) and 78.26% (18/23), respectively, whereas other AMR genes detected in the selected MDR enterococci from the cloacal swabs and meat were beta-lactamase TEM [blaTEM (0%, 1.96%)], class 1 integrase [intI1 (14.28%, 0%)], colistin [mrc–1 (3.57%, 0%)], and vancomycin [vanA (14.28%, 0%)]. This study indicated that phenotypic MDRE correlated with ESBL-TEM gene presence, leading to an AMR reservoir that can be transferred to other bacteria.

Background and Aim: Poultry meat is a popular food consumed globally. However, poultry farming is a source of Salmonella contamination which causes human salmonellosis. This study aimed to estimate the prevalence and antimicrobial resistance (AMR) of Salmonella among chickens and meat at poultry slaughterhouses in province study areas in Thailand and Japan. Materials and Methods: Chicken meat and feces samples were collected in Thailand and Japan. In Nakhon Ratchasima Province, Thailand, 558 samples were obtained from slaughterhouses from January 2021 to March 2022. In Gifu Prefecture, Japan, 140 samples (70 each of intestinal contents and meat) were purchased from slaughterhouses from June to October 2022. For Salmonella detection, the samples were cultivated according to the International Organization for Standardization 6579:2002/AMD 1:2007 method and confirmed using polymerase chain reaction (PCR) and agglutination tests for serotyping. Isolated Salmonella were tested for AMR to nine antibiotics using the disk diffusion method. Selected phenotypic multidrug-resistant (MDR) isolates were evaluated for AMR genes (AMRGs) using PCR. Results: Salmonella prevalence from chickens and meat at slaughterhouses in Thailand and Japan was 41.2% and 40.7%, respectively. All the Salmonella isolates in Japan were serotyped as Schwarzengrund, and no Salmonella isolates were resistant to the nine antibiotics tested. In contrast, most of the Thai Salmonella isolates from chicken cloacal swabs and meat were resistant to doxycycline (78.3%) and colistin (63.5%). The prevalence of MDR Salmonella (MDRS) in chickens and meat from Thailand and Japan was 29.1% (67/230) and 0% (0/57), respectively. However, the most frequent AMRGs found in MDRS in Thailand were extended-spectrum beta-lactamase-Temoneira (ESBL-TEM) (45.1%). All isolated Salmonella from Japan revealed a class 1 integron gene (Int-1). Conclusion: Phenotypic MDRS isolates from Thailand showed the greatest correlation to AMRG and ESBL-TEM. Although there were no phenotypic AMR Salmonella isolates found in Japan, they can be found associated with Int-1, which may carry other AMRGs within the gene cassettes. Keywords: antimicrobial resistance, broiler chickens, meat, Salmonella, slaughterhouse.