Siddiqui Mohammad Tahir, Mondal Aftab Hossain, Gogry Firdoos Ahmad, Husain Fohad Mabood, Alsalme Ali, Haq Qazi Mohd Rizwanul
Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India.
Department of Food Science and Nutrition, College of Food and Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia.
Antibiotics (Basel). 2020 Nov 19;9(11):826. doi: 10.3390/antibiotics9110826.
Antibiotic resistance is one of the major current global health crises. Because of increasing contamination with antimicrobials, pesticides, and heavy metals, the aquatic environment has become a hotspot for emergence, maintenance, and dissemination of antibiotic and heavy metal resistance genes among bacteria. The aim of the present study was to determine the co-resistance to quinolones, ampicillin, and heavy metals among the bacterial isolates harboring extended-spectrum β-lactamases (ESBLs) genes. Among 73 bacterial strains isolated from a highly polluted stretch of the Yamuna River in Delhi, those carrying CTX-M, TEM, or SHV genes were analyzed to detect the genetic determinants of resistance to quinolones, ampicillin, mercury, and arsenic. The plasmid-mediated quinolone resistance (PMQR) gene was found in 22 isolates; however, the , and genes could not be detected in any of the bacteria. Two variants of CMY, CMY-2 and CMY-42, were identified among eight and seven strains, respectively. Furthermore, , and genes were detected in 40, 40, 44, and 24 bacterial strains, respectively. Co-transfer of different resistance genes was also investigated in a transconjugation experiment. Successful transconjugants had antibiotic and heavy metal resistance genes with similar tolerance toward antibiotics and heavy metals as did their donors. This study indicates that the aquatic environment is a major reservoir of bacteria harboring resistance genes to antibiotics and heavy metals and emphasizes the need to study the genetic basis of resistant microorganisms and their public health implications.
抗生素耐药性是当前全球主要的健康危机之一。由于抗菌剂、杀虫剂和重金属污染日益严重，水生环境已成为细菌中抗生素和重金属耐药基因产生、维持和传播的热点。本研究的目的是确定携带超广谱β-内酰胺酶（ESBLs）基因的细菌分离株对喹诺酮类、氨苄青霉素和重金属的共同耐药性。在从德里亚穆纳河高度污染河段分离出的73株细菌中，对携带CTX-M、TEM或SHV基因的菌株进行分析，以检测对喹诺酮类、氨苄青霉素、汞和砷的耐药性遗传决定因素。在22株分离株中发现了质粒介导的喹诺酮耐药性（PMQR）基因；然而，在任何细菌中均未检测到 、 和 基因。分别在8株和7株菌株中鉴定出CMY的两种变体，即CMY-2和CMY-42。此外，分别在40、40、44和24株细菌中检测到 、 和 基因。还通过接合转移实验研究了不同耐药基因的共同转移。成功的接合子具有抗生素和重金属耐药基因，对抗生素和重金属的耐受性与其供体相似。本研究表明，水生环境是携带抗生素和重金属耐药基因细菌的主要储存库，并强调有必要研究耐药微生物的遗传基础及其对公共卫生的影响。
