Bista Sayara, Thapa Shrestha Upendra, Dhungel Binod, Koirala Pragya, Gompo Tulsi Ram, Shrestha Nabaraj, Adhikari Nabaraj, Joshi Dev Raj, Banjara Megha Raj, Adhikari Bipin, Rijal Komal Raj, Ghimire Prakash
Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu 44618, Nepal.
Central Veterinary Laboratory Ministry of Agriculture, Land Management and Cooperatives, Government of Nepal, Tripureshwor, Kathmandu 44618, Nepal.
Animals (Basel). 2020 Nov 7;10(11):2060. doi: 10.3390/ani10112060.
Plasmid-mediated resistance to the colistin in poultry is considered as an emerging problem worldwide. While poultry constitutes the major industry in Nepal, there is a paucity of evidence on colistin resistance in isolates causing natural infections in poultry. This study aimed to explore the prevalence of plasmid-mediated colistin resistance gene, in isolated from liver samples of dead poultry suspected of infections. A total of two hundred and seventy liver samples (227 broilers and 43 layers) from dead poultry suspected of colibacillosis were collected from post-mortem in the Central Veterinary Laboratory (CVL), Kathmandu, between 1 February and 31 July 2019. The specimens were processed to isolate and identify ; an antimicrobial susceptibility test (AST) using disk diffusion method was performed with 12 different antibiotics: Amikacin (30 µg), ampicillin (10 µg), ciprofloxacin (5 µg), chloramphenicol (30 µg), cefoxitin (30 µg), ceftazidime (30 µg), ceftriaxone (30 µg), cotrimoxazole (25 µg), gentamicin (10 µg), imipenem (10 µg), levofloxacin (5 µg) and tetracycline (30 µg). Colistin resistance was determined by agar dilution method and colistin-resistant strains were further screened for plasmid-mediated gene, using conventional polymerase chain reaction (PCR). Out of 270 liver samples, 53.3% (144/270) showed growth of . The highest number (54%; 109/202) of isolates was obtained in the liver samples from poultry birds (of both types) aged less than forty days. In AST, 95.1% (137/144) and 82.6% (119/144) of isolates were resistant against tetracycline and ciprofloxacin, respectively, while 13.2% (19/144) and 25.7% (37/144) isolates were resistant to cefoxitin and imipenem, respectively. In the same assay, 76.4% (110/144) isolates were multi-drug resistant (MDR). The phenotypic prevalence of colistin resistance was 28.5% (41/144). In the PCR assay, 43.9% (18/41) of colistin-resistant isolates were screened positive for plasmid-mediated . The high prevalence of in colistin-resistant isolates in our study is a cause of concern for the probable coming emergence of colistin resistance in human pathogens, due to horizontal transfer of resistant genes from poultry to human isolates.
家禽中质粒介导的对黏菌素的耐药性被认为是一个在全球范围内出现的问题。尼泊尔的主要产业是家禽业，但关于在家禽自然感染中分离出的菌株对黏菌素耐药性的证据却很少。本研究旨在探讨从疑似感染的死禽肝脏样本中分离出的质粒介导的黏菌素耐药基因的流行情况。2019年2月1日至7月31日期间，在加德满都中央兽医实验室（CVL），从疑似患有大肠杆菌病的死禽身上共采集了270份肝脏样本（227份肉鸡样本和43份蛋鸡样本）。对样本进行处理以分离和鉴定；使用纸片扩散法对12种不同抗生素进行抗菌药敏试验（AST）：阿米卡星（30μg）、氨苄西林（10μg）、环丙沙星（5μg）、氯霉素（30μg）、头孢西丁（30μg）、头孢他啶（30μg）、头孢曲松（30μg）、复方新诺明（25μg）、庆大霉素（10μg）、亚胺培南（10μg）、左氧氟沙星（5μg）和四环素（30μg）。通过琼脂稀释法测定黏菌素耐药性，并使用常规聚合酶链反应（PCR）对耐黏菌素菌株进一步筛选质粒介导的基因。在270份肝脏样本中，53.3%（144/270）显示有细菌生长。在年龄小于40天的家禽（两种类型）的肝脏样本中，分离出的细菌数量最多（54%；109/202）。在抗菌药敏试验中，分别有95.1%（137/144）和82.6%（119/144）的分离菌株对四环素和环丙沙星耐药，而分别有13.2%（19/144）和25.7%（37/144）的分离菌株对头孢西丁和亚胺培南耐药。在同一项试验中，76.4%（110/144）的分离菌株对多种药物耐药（MDR）。黏菌素耐药的表型流行率为28.5%（4
