Antimicrobial resistance (AMR) in poultry production chain is one of the major food safety concerns due to indiscriminate usage of antibiotics and the presence of pathogens such as Salmonella which causes infections in various stages of production. In the present study, 182 samples were collected from commercial broiler supply chain, viz., three hatcheries (n = 29), three commercial broiler farms (CBF; n = 99), and three retail meat shops (RMS; n = 54), and used for isolation and identification of Salmonella using three different selective agar media and a selective enrichment medium followed by PCR confirmation targeting the hilA gene. The overall prevalence of Salmonella was 47/182 (25.82%), and a significantly higher (P < 0.05) prevalence was observed in retail meat shops (46.29%), CBF (19.19%), and hatcheries (10.34%). Comparison of three agar media for isolation of Salmonella revealed that all the media were equally selective. However, PCR amplification of hilA gene fragment was significantly higher (P < 0.01) in selective enrichment culture tetrathionate brilliant green bile broth (TTB) as compared to all solid (agar‐based) media. Susceptibility pattern against most frequently used antibiotics revealed that 100% of the isolates were resistant to at least one antibiotic. High resistance was observed for doxycycline (94.34%), followed by cefpodoxime (84.91%), ciprofloxacin (72.64%), gentamicin (65.09%), enrofloxacin (61.32%), colistin sulphate (40.42%), amikacin (34.91%), ampicillin (33.96%), neomycin (33.02), cefotaxime (30.19%), ceftazidime (29.25%), trimethoprim‐sulfamethoxazole (23.58%), amoxicillin+clavulanic acid (21.70%), and chloramphenicol (12.26%); 16.98% of the isolates were ex‐tended spectrum β‐lactamase (ESBL) producers, and 76.41% were multidrug resistant (MDR). MDR Salmonella were significantly higher (P < 0.01) in RMS (91.66%) followed by CBF (82.75%), whereas no MDR isolates were present in the isolates from hatcheries. The results indicated a higher prevalence of Salmonella and AMR for commonly used antibiotics in the complete broiler supply chain, especially RMS and CBF. Also, this study idicated that TTB enrichment followed by PCR and colony PCR was found to be rapid, specific and time‐saving method.

Background/Objectives: Understanding beef cattle farmers’ knowledge, attitudes, and practices on infectious disease prevention, antimicrobial use, and antimicrobial resistance (AMR) is important to developing stewardship programs. Methods: A cross-sectional stratified mail or phone survey of beef cattle producers in Illinois was conducted between June and August 2022. Ordinal logistic regression models assessed the impact of having a biosecurity plan on beef cattle farmers’ familiarity with cattle diseases. Logistic regression models evaluated associations between antimicrobial treatment practices and the type of cattle operations. Results: A total of 514 producers responded to all or some of the questions. Only 45% of producers were familiar with AMR, and 11% were concerned about cattle infections with antibiotic-resistant bacteria. Producers agreed or strongly agreed (64%) that inappropriate AMU contributes to the development of AMR. Most producers (70%) thought that antimicrobials were as effective in treating infectious diseases as 5 years ago. Only 50% of farms were visited by a veterinarian in the previous year and 35% had their biosecurity evaluated. Producers were more familiar with infectious diseases if their farm biosecurity was assessed. Treating respiratory infections was the most common reason for antimicrobial use. Compared to cow–calf farmers, whole-cycle farmers had a higher probability of having their farm’s biosecurity evaluated (OR = 1.66) and having a veterinarian visit in the previous year (OR = 2.16). Whole-cycle (OR = 3.92) and stocker/backgrounder (OR = 2.18) farmers had a higher probability of treating their cattle with antibiotics than cow–calf farmers. Conclusions: Antimicrobial stewardship and farm biosecurity programs are needed to raise awareness of disease prevention, AMU, and AMR among Illinois beef cattle producers.

The emergence of antimicrobial-resistant non-typhoidal Salmonella (NTS) in retail chicken meat poses a food safety risk. Data on antimicrobial resistance (AMR) in NTS isolates collected by the National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS) from retail chicken meat across the United States of America between 2013 and 2020 were analyzed. A total of 3,067 samples tested positive for NTS. The most common NTS serovars were S. Kentucky (n = 1,088), S. Infantis (n = 587), S. Enteritidis (n = 475), and S. Typhimurium (n = 424), respectively. A significant increasing trend in the proportion of S. Infantis and a decreasing trend for S. Typhimurium has been observed. High-proportion clusters were detected in the northeast and southeast of the United States of America for S. Typhimurium and in the west coast and southeast for S. Kentucky. Multidrug resistance (resistance to at least three antimicrobial classes) was common in S. Infantis and S. Typhimurium isolates, while S. Enteritidis isolates were mainly pan-susceptible. The predicted probability of resistance to beta-lactam antibiotics (ampicillin and ceftriaxone), sulfonamides (sulfisoxazole), and quinolones (nalidixic acid) were highest in S. Infantis isolates, while S. Kentucky isolates showed the highest probability of resistance to aminoglycosides (streptomycin) and tetracyclines. Differences in the geographical distribution of NTS serovars and variations in their AMR patterns warrant serovar-specific antimicrobial stewardship programs.

The emergence of antimicrobial resistance (AMR) across the broiler production chain holds significant economic, animal, and public health implications. This study investigated phenotypic resistance to 13 antimicrobials and the presence of 35 antimicrobial resistance genes (ARGs) in Escherichia coli (n = 291) isolated across three broiler production chains (broiler breeder farms, hatcheries, commercial broiler farms, and retail meat shops). An extremely high phenotypic resistance (>70%) to doxycycline, ciprofloxacin, and cefpodoxime, and very high resistance (50–70%) to ampicillin, cefotaxime, gentamicin, and ceftazidime was observed. In addition, 97% of isolates were multidrug-resistant (resistant to ≥1 drug in ≥3 antimicrobial classes), 42% were extended-spectrum beta-lactamase (ESBL) producers, 65% were resistant to third-generation cephalosporins (3GCR), and 21% were resistant to colistin. The Poisson regression model revealed no significant difference in AMR among broiler production stages, except for colistin. Among 35 ARGs tested, 24 (67%) were detected at least once. The most prevalent were tetA, bla_TEM, qnrB, qnrS, and aac(6′)-Ib-cr, while qnrD, sul2, bla_OXA, and bla_CTX-M were detected at lower levels (1–7%). All five tested mcr genes (mcr-1 to mcr-5) were identified in commercial farms and retail shops. No bla_NDM, tetB, tetC, tetD, tetM, qnrC, aac(3)-IIa (aacC2), aph(3)-IIa (aphA2), or aac(6′)-Ib genes were found. A strong correlation was observed between AMR phenotypes and ARGs. High AMR among E. coli in broiler production poses significant One Health risks, with widespread MDR, ESBL production, and resistance to critically important antimicrobials. Prudent antimicrobial use, enhanced surveillance and education, farm biosecurity, and One Health strategies are crucial in mitigating these threats.

Background: Subacute ruminal acidosis (SARA) is one of the most important metabolic disease of dairy cattle which decrease milk production, dry matter intake, productivity and increase culling rate and even cause death. Methods: In this study the epidemiological status of SARA namely age, breed, stage of lactation, lactation number, general health condition, body condition score, daily milk production, milk fat content and biochemical alteration were investigated. Result: Out of 100 cows examined 20 were found to be positive for SARA and the mean age of dairy cows suffering from SARA was found to be 6.53 ±0.68 years. The prevalence of SARA was 70 and 30 per cent in Jersey and HF breed of cows respectively and was high in mid lactation and the lactation number ranged from 2 to 6. 65 per cent. SARA affected cows were in poor body condition score, milk production and milk fat content was significantly low (P≤ 0.05). The mean GGT (Gamma Glutamyl Transferase) and AST (Asparate aminotransferase) values were significantly increased in SARA affected dairy cows. SARA seems to be a common problem in dairy cattle and it has to be considered when dealing with herd level problems like low milk fat, low milk production, poor body condition and appropriate management measures should be implemented to prevent it.

The emergence and dissemination of antimicrobial resistance genes (ARGs) in poultry‐origin Salmonella spp. pose a threat to food safety. This study characterized the genotypic antimicrobial resistance (AMR) in Salmonella spp. isolates across the broiler chicken production chain in Karnataka, India, and the co‐occurrence between AMR phenotypes and genotypes. Samples were collected from hatcheries (HAT), commercial broiler farms (CBFs), and retail meat shops (RMSs). A total of 106 Salmonella spp. isolates were obtained and screened for 35 ARGs belonging to seven antimicrobial classes using polymerase chain reaction (PCR). In total, 20/35 ARGs (57%) were detected in Salmonella spp. isolates from the entire production chain. The tetA (70%), bla _TEM (50%), mcr-2–mcr-5 (29%–35%), aac (6 ^′ )‐Ib‐cr (21%), qnrS (19%), qnrD (18%), cmlA1 (13%), and sul1 (8%) were the most prevalent ARGs detected. The principal component analysis revealed distinct ARG profiles by production stage, with the highest diversity of ARGs found in RMS. All five mcr genes were detected in CBFs and RMSs, raising concerns about resistance to colistin, a last‐resort antibiotic for human medicine. The highest co‐occurrence was observed between doxycycline resistance and the tetA gene. Hierarchical clustering for AMR phenotypes and genotypes was performed using Ward′s minimum variance method. A main cluster was identified, which included co‐occurrence of resistance to tetracyclines, quinolones, aminoglycosides, and β ‐lactams within the same isolates. Clustering of AMR phenotypes did not result in clear separation of isolates by source (HAT, CBFs, or RMSs), suggesting dissemination or persistence of shared resistance profiles across production stages. This study highlights the presence and diversity of ARGs, as well as resistance to critically important antimicrobials, and calls for interventions, including antimicrobial stewardship, enhanced biosecurity, good farming and meat processing practices, and routine surveillance to mitigate AMR.