Antimicrobial resistance (AMR) is a major global public health issue. In India, access to medicines is poorly regulated and therefore antibiotics in dairy cattle are commonly used by farmers withou...

The use and misuse of antibiotics in both humans and animals contributes to the global emergence of antimicrobial resistant (AMR) bacteria, a threat to public health and infection control. Currently, India is the world’s leading milk producer but antibiotic usage within the dairy sector is poorly regulated. Little data exists reflecting how antibiotics are used on dairy farms, especially on small-scale dairy farms in India. To address this lack of data, a study was carried out on 491 small-scale dairy farms in two Indian states, Assam and Haryana, using a mixed method approach where farmers were interviewed, farms inspected for the presence of antibiotics and milk samples taken to determine antibiotic usage. Usage of antibiotics on farms appeared low only 10% (95% CI 8–13%) of farmers surveyed confirmed using antibiotics in their dairy herds during the last 12 months. Of the farms surveyed, only 8% (6–11%) had milk samples positive for antibiotic residues, namely from the novobiocin, macrolides, and sulphonamide classes of antibiotics. Of the farmers surveyed, only 2% (0.8–3%) had heard of the term “withdrawal period” and 53% (40–65%) failed to describe the term “antibiotic”. While this study clearly highlights a lack of understanding of antibiotics among small-scale dairy farmers, a potential factor in the emergence of AMR bacteria, it also shows that antibiotic usage on these farms is low and that the possible role these farmers play in AMR emergence may be overestimated.

Bovine milk and milk products may contain pathogens, antimicrobial resistant bacteria, and antibiotic residues that could harm consumers. We analyzed 282 gram-positive isolates from milk samples from dairy farmers and vendors in Haryana and Assam, India, to assess the prevalence of methicillin-resistant staphylococci using microbiological tests, antibiotic susceptibility testing, and genotyping by PCR. The prevalence of genotypic methicillin resistance in isolates from raw milk samples was 5% [95% confidence interval, CI (3–8)], with 7% [CI (3–10)] in Haryana, in contrast to 2% [CI (0.2–6)] in Assam. The prevalence was the same in isolates from milk samples collected from farmers [5% (n = 6), CI (2–11)] and vendors [5% (n = 7), CI (2–10)]. Methicillin resistance was also observed in 15% of the isolates from pasteurized milk [(n = 3), CI (3–38)]. Two staphylococci harboring a novel mecC gene were identified for the first time in Indian dairy products. The only SCCmec type identified was Type V. The staphylococci with the mecA (n = 11) gene in raw milk were commonly resistant to oxacillin [92%, CI (59–100)] and cefoxitin [74%, CI (39–94)], while the isolates with mecC (n = 2) were resistant to oxacillin (100%) only. All the staphylococci with the mecA (n = 3) gene in pasteurized milk were resistant to both oxacillin and cefoxitin. Our results provided evidence that methicillin-resistant staphylococci occur in dairy products in India with potential public health implications. The state with more intensive dairy systems (Haryana) had higher levels of methicillin-resistant bacteria in milk.

The consumption of milk contaminated with antibiotic-resistant bacteria poses a significant health threat to humans. This study aimed to investigate the prevalence of Enterobacteriaceae producing β-lactamases (ESBL, MBL, and AmpC) in cow and buffalo milk samples from two Indian states, Haryana and Assam. A total of 401 milk samples were collected from dairy farmers and vendors in the specified districts. Microbiological assays, antibiotic susceptibility testing, and PCR-based genotyping were employed to analyze 421 Gram-negative bacterial isolates. The overall prevalence of β-lactamase genes was 10% (confidence interval (CI) (7–13)), with higher rates in Haryana (13%, CI (9–19)) compared to Assam (7%, CI (4–11)). The identified β-lactamase genes in isolates were bla_CMY, bla_MOX, bla_FOX, bla_EBC, and bla_DHA, associated with AmpC production. Additionally, bla_CTX-M1, bla_SHV, and bla_TEM were detected as ESBL producers, while bla_VIM, bla_IMP, bla_SPM, bla_SIM, and bla_GIM were identified as MBL producers. Notably, Shigella spp. were the dominant β-lactamase producers among identified Enterobacteriaceae. This study highlights the presence of various prevalent β-lactamase genes in milk isolates, indicating the potential risk of antimicrobial-resistant bacteria in dairy products. The presence of β-lactam resistance raises concern as this could restrict antibiotic options for treatment. The discordance between genotypic and phenotypic methods emphasizes the necessity for comprehensive approaches that integrate both techniques to accurately assess antibiotic resistance. Urgent collaborative action incorporating rational and regulated use of antibiotics across the dairy value chain is required to address the global challenge of β-lactam resistance.

Traditional fermented food products are often connected to various indigenous tribes and thus vary due to ethnicity, geography, and natural resource availability. The indigenous tribes from India greatly rely on fermentation processes for food preservation, flavor, and nutrition. Fermented foods can provide health benefits but also pose risks from harmful microbes and contaminants that grow in the food due to poor hygiene. In this study, we identified lactic acid bacteria (LAB) in fermented food collected from Northeast India, assessed their beneficial properties, and highlighted the risk from food pathogens that have antimicrobial resistance traits. A total of 113 different samples of fermented food products were collected from the local markets of five Northeastern Indian states (Nagaland, Manipur, Meghalaya, Arunachal Pradesh, and Sikkim). Standard laboratory methods were used to isolate LAB and determine their probiotic properties, conduct coliform counts, and isolate presumptive staphylococci from the fermented food samples. Antimicrobial susceptibility was determined by using the BD-Phoenix 100 automated system. We isolated 30 LAB with probiotic potential. The average aerobic colony count in different fermented food was 4.4–7.7 log·cfu/g, while coliforms were present in 43% (49/113, 95% (CI 34–53)) of the food samples, indicating low-hygiene levels. Additionally, some food samples contained staphylococci with phenotypic antibiotic-resistance markers (MRS, HLMUP, BLACT, and STAMLS). This study indicates that probiotic bacteria could be present in traditional fermented food products of Northeast India, but contamination with staphylococci and other bacterial pathogens with antibiotic resistance traits could put the health of consumers at risk.

Antimicrobial resistance (AMR) in food products represents a potential public health risk in low- and middle-income countries, yet evidence from Indian milk production systems remains limited. A cross-sectional study was conducted using 256 milk samples collected from farms and vendors in Assam and Haryana, India. AMR prevalence was high (90%) with no state-level differences. Dual AMR (both Gram-positive and Gram-negative bacteria) occurred in 48% [95% confidence interval (CI) 42–55] of samples, while multidrug resistance (MDR) was also 48% [CI 42–55], but were not significant. Dual AMR was only present in 7% of samples [CI 4–11]. AMR bacteria were detected in milk from both informal and more organised dairy systems. In multivariable analyses, none of the investigated farm-level or vendor-level predictors showed strong or consistent associations with AMR outcomes after adjustment. However, due to limited statistical power and sparse outcomes, the observed associations should be interpreted cautiously. The findings are primarily descriptive and highlight the need for larger, systematically designed studies to better understand drivers of AMR along the Indian dairy value chain.