Pharmaceutical disposal facilitates the mobilization of resistance determinants among microbiota of polluted environment

Mudsser Azam; Vijay Kumar; Kehkashan Siddiqui; Arif Tasleem Jan; Jamal S M Sabir; Irfan A Rather; Suriya Rehman; Qazi Mohd Rizwanul Haq

doi:10.1016/j.jsps.2020.10.009

Pharmaceutical disposal facilitates the mobilization of resistance determinants among microbiota of polluted environment

Saudi Pharm J. 2020 Dec;28(12):1626-1634. doi: 10.1016/j.jsps.2020.10.009. Epub 2020 Oct 28.

Authors

Mudsser Azam¹, Vijay Kumar², Kehkashan Siddiqui¹, Arif Tasleem Jan³, Jamal S M Sabir^{4

5}, Irfan A Rather^{4

5}, Suriya Rehman⁶, Qazi Mohd Rizwanul Haq¹

Affiliations

¹ Department of Biosciences, Jamia Millia Islamia, New Delhi, India.
² Department of Biotechnology, Yeungnam University, Gyeongsan, Republic of Korea.
³ School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India.
⁴ Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah -21589, Saudi Arabia.
⁵ Center of Excellence for Bionanoscience Research, King Abdulaziz University, Jeddah -21589, Saudi Arabia.
⁶ Department of Epidemic Disease Research, Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, 31441 Dammam, Saudi Arabia.

Abstract

The emergence of resistance on exposure to pharmaceuticals among microorganisms has raised serious concern in the therapeutic approach against infectious diseases. Effluents discharge from hospitals, industries, and urban settlements containing pharmaceuticals and other toxic compounds into the aquatic ecosystem selects bacterial population against them; thereby promotes acquisition and dissemination of resistant traits among the inhabitant microbiota. The present study was aimed to determine the prevalence and multidrug resistance pattern of Extended Spectrum β-lactamase (ESBL) producing and non-producing bacterial isolates from the heavily polluted Delhi stretch of river Yamuna, India. Additionally, the role of abiotic factors in the dissemination of conjugative plasmids harbouring resistance genes was also studied using E. coli J53 as recipient and resistant E. coli isolates as donor strains. Of the 227 non-duplicate bacterial isolates, 60% (136) were identified as ESBL⁺ and 40% (91) as ESBL. ESBL⁺ isolates were found highly resistant to β-lactam and non-β-lactam classes of antibiotics compared with the ESBL^- isolates. 68% of ESBL⁺ and 24% of ESBL^- isolates showed an MAR index of ≥0.5. Surprisingly, multidrug resistance (MDR), extensively drug resistance (XDR), and pandrug resistance (PDR) phenotype were observed for 78.6%, 16.9%, and 0.7% of ESBL⁺ and 90%, 3%, and none for PDR among ESBL^- isolates. Conjugation under different conditions showed a higher mobilization rate at neutral pH (7-7.5) for ESBL⁺ isolates. Conjugation frequency was maximum at 40 °C for the isolate E. coli MRB6 (4.1 × 10^-5) and E. coli MRE32 (4.89 × 10^-4) and at 35 °C for E. coli MRA11 (4.89 × 10^-5). The transconjugants obtained were found tolerating different concentrations of mercuric chloride (0.0002-0.2 mg/L). Increased biofilm formation for ESBL⁺ isolates was observed on supplementing media with HgCl₂ (2 μg/mL) either singly or in combination with CTX (10 μg/mL). The present study demonstrates that anthropogenically influenced aquatic environments act as a reservoir of MDR, XDR, and even PDR strains; thereby posing a potent public health risk.

Keywords: Conjugation frequency; Dissemination; E. coli; ESBLs; Multidrug resistance; Resistance prevalence.