<div style="text-align:justify"><strong>Background:</strong> Shiga toxin-producing Escherichia coli (STEC) strains are considered to be most common food-borne enteric zoonotic pathogen, causing various disease conditions in both animals and humans and are highly pathogenic to human in low infectious doses. Resistance against antibiotics by STEC is also a big concern now a days. Hence in view of the public health significance of STEC, present work was planned to know the combination of phenotypic and genotypic resistance patterns against certain most commonly used antibiotics by using disk diffusion method and multiplex PCR respectively.<br />
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<strong>Methods:</strong> A total of 426 PCR confirmed STEC isolates isolated from pooled samples (animal faecal(179), farm water(122) and human faecal samples (125) of different livestock farms in and around Proddatur andhra Pradesh, were subjected to antibiotic sensitivity test by using disc diffusion method. The isolates that showed resistance for tetracycline, streptomycin, sulphonamides and ampicillin were selected and subjected to multiplex PCR for the detection of resistance genes.<br />
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<strong>Result:</strong> Disk diffusion assay revealed highest phenotypic resistance for STEC isolates against Cepahlothin (100%), followed by Ampicillin (99.06%), Tetracycline (97.2%), Streptomycin (94.3%), Sulphonamides (90.8%) and Trimethoprim (84.5%). Pooled samples also revealed the presence of antimicrobial resistance genes like tetA(59.2%), tetB(43.5%), tetC (9.2%), strA (39.3%), strB(54.1%), sul1 (40.8%), sul2 (58.7%), sul3 (3.8%) and blaTEM(83.4%). These findings indicate the highest prevalence of antimicrobial resistance among the STEC isolates, which alarms indiscriminate use of antibiotics both for therapeutic purpose and as growth promoters. Strict hygienic, sanitation and HACCP programmes should be applied to counter STEC prevalence.</div>

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<p>Detection of Antimicrobial Resistance Genes from Shiga Toxin Producing Escherichia coli by Multiplex PCR</p>

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<div style="text-align: justify;"><strong>Background:</strong> Antibiotics are commonly used in animal husbandry for medicinal, prophylactic and growth promotion purposes.<br /><strong>Method: </strong>The prevalence of three groups of antibiotics; namely Gentamycin, Streptomycin and sulfonamides was studied in fresh milk available in five different study areas; namely Budhanilkantha, Dharmasthali, Tokha, Nepaltar and Gaushala from Kathmandu Valley of Nepal. The milk samples (n=100) were collected from local dairy collection centers of Kathmandu valley. Qualitative and semi-quantitative analysis with rapid screening kits revealed that 6% (n=6) samples were positive for antibiotic residues in the fresh milk for gentamycin, streptomycin and sulfonamide groups. Total 5% milk samples contained unidentified antibiotics residues. Sulfonamides residues were found to be highest 3% (n=3) followed by gentamycin 2% (n=2) and streptomycin 1% (n=1) with no any milk sample with multiple residues. Total 2 samples were positive in Dharmasthali, 2 in Gaushala, 1 in Nepaltar, 1 in Tokha and no positive samples from Budhanilkantha area. There was no statistical significant difference between study areas and commonly used antibiotics residues in milk samples (P&gt;0.05).&nbsp;<br /><strong>Conclusion:</strong> The antibiotic residues were found above the maximum residue limits that presented serious threat to consumer health and raised a serious concern regarding the implementation and monitoring of international regulations.&nbsp;</div>

Detection of Antimicrobial Resistance Genes from Shiga Toxin Producing Escherichia coli by Multiplex PCR

Determination of Antibiotics Residues in Milk Samples Collected in the Different Sites of Kathmandu, Nepal