Genetic characterization of fluoroquinolone-resistant Escherichia coli associated with bovine mastitis in India

Abstract

Aim:The present study was undertaken to characterize the mutation in gyrA (DNA gyrase) and parC (topoisomerase IV) genes responsible for fluoroquinolone resistance in Escherichia coli isolates associated with the bovine mastitis.Materials and Methods:A total of 92 milk samples from bovine mastitis cases were sampled in and around Puducherry (Southern India). Among these samples, 30 isolates were bacteriologically characterized as E. coli. Minimum inhibitory concentrations (MIC) of fluoroquinolones of these 30 E. coli isolates were evaluated by resazurin microtiter assay. Then, the quinolone resistance determining region (QRDR) (gyrA and parC genes) of these E. coli isolates was genetically analyzed for determining the chromosomal mutation causing fluoroquinolone resistance.Results:E. coli isolates showed a resistance rate of 63.33%, 23.33% and 30.03% to nalidixic acid, ciprofloxacin and enrofloxacin, respectively. Mutations were found at 83rd and 87th amino acid position of gyrA gene, and at 80th and 108th amino acid position of parC gene in our study isolates. Among these five isolates, one had a single mutation at 83 amino acid position of gyrA with reduced susceptibility (0.5 µg/ml) to ciprofloxacin. Then, in remaining four isolates, three isolates showed triple mutation (at gyrA: S83⟶L and D87⟶N; at parC: S80⟶I) and the fifth isolate showed an additional mutation at codon 108 of parC (A108⟶T) with the increased ciprofloxacin MIC of 16-128 µg/ml. The most common mutation noticed were at S83⟶L and D87⟶N of gyrA and S80⟶I of ParC.Conclusion:The study confirms the presence of mutation/s responsible for fluoroquinolone resistance in QRDR of gyrA and parC genes of E. coli isolates of animal origin, and there is increased rate of fluoroquinolone resistance with high-level of MIC. The mutations observed in this study were similar to that of human isolates.

Characteristics of Quinolone Resistance in Escherichia coli Isolates from Humans, Animals, and the Environment in the Czech Republic

“…Isolates from poultry and rooks that displayed clinical levels of ciprofloxacin resistance linked to single or double mutations in gyrA and parC were found in our study. Strains of various animal origin with these types of mutations have been recently found worldwide (Sáenz et al, 2003; Liu et al, 2012; Castillo et al, 2013; Johnning et al, 2015; Balakrishnan et al, 2016). …”

Synanthropic rodents and shrews are reservoirs of zoonotic bacterial pathogens and act as sentinels for antimicrobial resistance spillover in the environment: A study from Puducherry, India

“…It is also commonly used for water treatment in poultry houses, thus making sulfonamides as a major environment pollutant in the poultry house effluents [ 54 ]. Balakrishnan et al , 2016 [ 30 ] isolated fluoroquinolones resistant E. coli isolates of animal origin from Puducherry. In contrast, Ramatla et al, 2022 [ 55 ] found a higher percentage of qnrA and tet gene resistance in rodents in South Africa.…”

“…Representative samples from the isolates tested to have AMR genes were used to carry out the antibiotic sensitivity test (ABST) using the antibiotic impregnated discs procured from Hi Media Laboratories, India. ABST was carried out following the standard procedure [ 30 ]. Methicillin resistance in S. aureus was confirmed using Methicillin (M) 5 μg.…”

Development and Efficacy Evaluation of an SP01-adjuvanted Inactivated Escherichia Coli Mutant Vaccine Against Bovine Coliform Mastitis

“…Although antibiotics are an optimal treatment for bovine clinical mastitis [10][11][12][13], the massive use of antimicrobial drugs has led to the emergence of drug-resistant strains of E. coli, thus making effective prevention and treatment of mastitis extremely difficult [9,[14][15][16][17][18]. In the context of the current advocacy of resistance reduction initiatives, methods using biological agents against mastitis are being developed, including phage therapy, antimicrobial therapy, antibody therapy, nonspecific immune boosting prophylaxis and vaccine prophylaxis.…”