Isolation of multidrug-resistant and spp. from sulfonamide-treated diarrheic calves.

BACKGROUND AND AIM

The bovine industry is threatened by one of the most serious and deadly enteric diseases, calf diarrhea, particularly in developing nations like Bangladesh. In this context, bacterial resistance to antimicrobial drugs and its detrimental consequences have become a critical public health issue that is difficult to address globally. This study aimed to isolate and identify and spp. with their antibiogram and antibiotic resistance gene detection from sulfonamide-treated diarrheic calves.

MATERIALS AND METHODS

Twelve diarrheic calves suffering from calf diarrhea in a dairy farm were selected and a total of 36 fecal samples were aseptically collected directly from rectum before, during, and at the end of treatment for each calf to determine the total viable count, total count and total count. A polymerase chain reaction was used for the specific detection of and genus targeting and genes, respectively. Antibiotic sensitivity test of the isolated and spp. were performed by the disk diffusion method for eight commonly used antibiotics.

RESULTS

A total of 36 (100%) and 12 spp. (33%) were isolated from the samples and were confirmed by polymerase chain reaction. Total viable count was found to be ranged from 35 × 10 to 99 × 10 colony-forming unit (CFU)/g fecal sample before starting sulfonamide treatment, 34 × 10 to 25 × 10 CFU/g during treatment with sulfonamide, and 48 × 10 to 69 × 10 CFU/g immediately after completion of sulfonamide treatment. Total count was found to be ranged from 4 × 10 to 36 × 10 CFU/g, 24 × 10 to 23 × 10 CFU/g, and 13 × 10 to 85 × 10 CFU/g, whereas total count was found to be ranged from 16 × 10 to 18.5 × 10 CFU/g, 15 × 10 to 44 × 10 CFU/g, and 13.2 × 10 to 21 × 10 CFU/g fecal sample before starting sulfonamide treatment, during treatment with sulfonamide immediately after completion of sulfonamide treatment, respectively. The antibiotic sensitivity test showed that all the and spp. isolated from diarrheic calves (100%) contained multidrug-resistant (MDR) phenotypes. isolates were found 100% resistant to amoxicillin (AMX), cefuroxime, cephalexin (CN), erythromycin (ERY), and tetracycline (TET); whereas 94.4%, 86.1%, and 77.8% isolates were resistant to doxycycline (DOX), moxifloxacin (MOF), and gentamycin (GEN), respectively. In case of isolates, all were found 100% resistant to AMX, CN, and ERY; whereas 91.7% of resistance was observed for DOX, MOF, cefuroxime, GEN, and TET. Based on the molecular screening of the antibiotic resistance genes, A gene was present in 83.3% of the isolated and 75% of the isolated strains, whereas 83.3% and 79.2% isolates contained TEM gene.

CONCLUSION

These findings suggest that MDR and spp. might be responsible for calf scouring, which is challenging to treat with antibiotics or sulfonamide drugs alone. Therefore, it is important to check the antibiotic sensitivity pattern to select a suitable antibiotic for the treatment of calf scoring. A suitable antibiotic or combination of an antibiotic and sulfonamide could be effective against and spp. responsible for calf scouring.