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Papers by Debaraj Bhattacharyya

Research paper thumbnail of Molecular Characterization of Multi Drug Resistant (MDR) Extended Spectrum βlactamase (ESBL) Producing Klebsiella spp. from Pond Water in West Bengal

Journal of scientific research, 2020

Bacterial antibiotic resistance is an emerging global healthcare threat. Enterobacteriaceae famil... more Bacterial antibiotic resistance is an emerging global healthcare threat. Enterobacteriaceae family is eminent for development and transfer of antibiotic resistance (AR's). To control the spread of drug-resistant bugs, the environmental microflora should be screened for the presence and spread of antibiotic resistant genes (ARG's). In order to determine the possibility and frequency of antibiotic resistant organisms in genus Klebsiella, 226 Klebsiella colonies were isolated from pond water (n=113). In total, 16.81% Klebsiella isolates were found MDR, of which, 76.19% carried bla CTX-M, 19.04% bla TEM, and 71.42% AmpC type beta-lactamase. However, 42.10% Klebsiella were both ESBL & AmpC type beta lactamase (ACBL) co-producer. In addition, 19.04% of the isolates emerged as carbapenemase producers. This study indicates that urban ponds may act as natural reservoir for antibiotic resistant bacterium.

Research paper thumbnail of First Report on Vancomycin-Resistant Staphylococcus aureus in Bovine and Caprine Milk

Microbial Drug Resistance, 2016

The present investigation was carried out to study the vancomycin resistance pattern of Staphyloc... more The present investigation was carried out to study the vancomycin resistance pattern of Staphylococcus aureus isolates (n = 274) obtained from 352 milk samples of bovine (269) and caprine (63) clinical and subclinical mastitis from different districts of West Bengal, India. Of them, seven isolates (vancomycin-resistant S. aureus [VRSA] 1-7) exhibited resistance to vancomycin. Minimum inhibitory concentration of vancomycin (MICvan) for VRSA2 and VRSA3 was ≥16 μg/ml; thus categorized as VRSA. For rest of the isolates, MICvan was 8 μg/ml and they were grouped as vancomycin intermediate S. aureus (VISA). Even though all the isolates were resistant to cefoxitin and oxacillin and possessed mecA gene, none of them carried vancomycin resistance gene. Furthermore, all the seven isolates were subjected to Staphylococcal cassette chromosome mec (SCCmec) typing, Staphylococcal protein A (spa) typing, and enterobacterial repetitive intergenic consensus polymerase chain reaction. All the isolates except VRSA3 and VRSA4 from Kolkata district exhibited diverse genetic lineage, irrespective of their host and antibiotic resistance pattern. These two isolates showed clonal similarity (MRSA-SCCmec-V-spa t267) with methicillin-resistant S. aureus (MRSA) strains previously reported in human and animal infection. Isolation of VRSA and VISA could probably be due to intensive use of vancomycin in healthcare premises, which might have led to the development of glycopeptide-resistant strains and thereafter, further disseminated in the environment, including livestock farms. Detection of VRSA in milk is a serious concern as it may further cause health problems in the consumers. This is the first ever report of VRSA in food animals, even though the pathogen is otherwise prevalent in humans.

Research paper thumbnail of Co-infection of methicillin-resistant Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus and extended spectrum β-lactamase producing Escherichia coli in bovine mastitis - three cases reported from India

The Veterinary quarterly, Jan 2, 2014

Emergence of antimicrobial resistance among bovine mastitis pathogens is the major cause of frequ... more Emergence of antimicrobial resistance among bovine mastitis pathogens is the major cause of frequent therapeutic failure and a cause of concern for veterinary practitioners. This study describes intra-mammary infection of methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum β-lactamase (ESBL) producing Escherichia coli in two Holstein Friesian crossbred cows with subclinical mastitis and one non-descript cow with clinical mastitis in two different districts of West Bengal, India. In total, three MRSE, one MRSA and three ESBL producing E. coli were isolated from these cases. Both the crossbreds were detected with MRSE (HFSE1 and HFSE2) and ESBL producing E. coli (HFEC1 and HFEC2), whereas, simultaneous infection of three pathogens viz. MRSA (NDSA1), MRSE (NDSE1) and ESBL producing E. coli (NDEC1) was found in the non-descript cow. The methicillin-resistant isolates possessed mecA gene and exhibited resistanc...

Research paper thumbnail of Molecular and phylogenetic characterization of the sieve element occlusion gene family in Fabaceae and non-Fabaceae plants

Previously, we characterized an undocumented strain of Eimeria krijgsmanni by morphological and b... more Previously, we characterized an undocumented strain of Eimeria krijgsmanni by morphological and biological features. Here, we present a detailed molecular phylogenetic analysis of this organism. Namely, 18S ribosomal RNA gene (rDNA) sequences of E. krijgsmanni were analyzed to incorporate this species into a comprehensive Eimeria phylogeny. As a result, partial 18S rDNA sequence from E. krijgsmanni was successfully determined, and two different types, Type A and Type B, that differed by 1 base pair were identified. E. krijgsmanni was originally isolated from a single oocyst, and thus the result show that the two types might have allelic sequence heterogeneity in the 18S rDNA. Based on phylogenetic analyses, the two types of E. krijgsmanni 18S rDNA formed one of two clades among murine Eimeria spp.; these Eimeria clades reflected morphological similarity among the Eimeria spp. This is the third molecular phylogenetic characterization of a murine Eimeria spp. in addition to E. falciformis and E. papillata.

Research paper thumbnail of Molecular and phylogenetic characterization of multidrug resistant extended spectrum beta-lactamase producing Escherichia coli isolated from poultry and cattle in Odisha, India

Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases, 2015

The present study was undertaken to determine the occurrence and characterization of extended spe... more The present study was undertaken to determine the occurrence and characterization of extended spectrum beta-lactamase (ESBL) producing Escherichia coli isolated from cattle and poultry in Odisha, India. Of 316 E. coli isolated from 305 samples (170 fecal samples from poultry and 135 milk samples from cattle), a total of 18 E. coli isolates were confirmed as ESBL producers by combination disc method and ESBL E-test. The isolates were resistant to oxyimino cephalosporins and monobactam as revealed by disc diffusion assay and determination of minimum inhibitory concentration. Resistance against other antibiotics was frequently noted as well. Further, beta-lactamase genes viz., blaSHV, blaCTXM, blaTEM and blaampC were detected in 17, 13, 9 and 2 isolates, respectively in PCR. Of the 18 ESBL strains, 16 were positive for class I integron (int1), nine of them carried sulphonamide resistance gene (sul1) and one harbored quinolone resistance gene (qnrB). Virulence markers for extraintestina...

Research paper thumbnail of Molecular Characterization of Multi Drug Resistant (MDR) Extended Spectrum βlactamase (ESBL) Producing Klebsiella spp. from Pond Water in West Bengal

Journal of scientific research, 2020

Bacterial antibiotic resistance is an emerging global healthcare threat. Enterobacteriaceae famil... more Bacterial antibiotic resistance is an emerging global healthcare threat. Enterobacteriaceae family is eminent for development and transfer of antibiotic resistance (AR's). To control the spread of drug-resistant bugs, the environmental microflora should be screened for the presence and spread of antibiotic resistant genes (ARG's). In order to determine the possibility and frequency of antibiotic resistant organisms in genus Klebsiella, 226 Klebsiella colonies were isolated from pond water (n=113). In total, 16.81% Klebsiella isolates were found MDR, of which, 76.19% carried bla CTX-M, 19.04% bla TEM, and 71.42% AmpC type beta-lactamase. However, 42.10% Klebsiella were both ESBL & AmpC type beta lactamase (ACBL) co-producer. In addition, 19.04% of the isolates emerged as carbapenemase producers. This study indicates that urban ponds may act as natural reservoir for antibiotic resistant bacterium.

Research paper thumbnail of First Report on Vancomycin-Resistant Staphylococcus aureus in Bovine and Caprine Milk

Microbial Drug Resistance, 2016

The present investigation was carried out to study the vancomycin resistance pattern of Staphyloc... more The present investigation was carried out to study the vancomycin resistance pattern of Staphylococcus aureus isolates (n = 274) obtained from 352 milk samples of bovine (269) and caprine (63) clinical and subclinical mastitis from different districts of West Bengal, India. Of them, seven isolates (vancomycin-resistant S. aureus [VRSA] 1-7) exhibited resistance to vancomycin. Minimum inhibitory concentration of vancomycin (MICvan) for VRSA2 and VRSA3 was ≥16 μg/ml; thus categorized as VRSA. For rest of the isolates, MICvan was 8 μg/ml and they were grouped as vancomycin intermediate S. aureus (VISA). Even though all the isolates were resistant to cefoxitin and oxacillin and possessed mecA gene, none of them carried vancomycin resistance gene. Furthermore, all the seven isolates were subjected to Staphylococcal cassette chromosome mec (SCCmec) typing, Staphylococcal protein A (spa) typing, and enterobacterial repetitive intergenic consensus polymerase chain reaction. All the isolates except VRSA3 and VRSA4 from Kolkata district exhibited diverse genetic lineage, irrespective of their host and antibiotic resistance pattern. These two isolates showed clonal similarity (MRSA-SCCmec-V-spa t267) with methicillin-resistant S. aureus (MRSA) strains previously reported in human and animal infection. Isolation of VRSA and VISA could probably be due to intensive use of vancomycin in healthcare premises, which might have led to the development of glycopeptide-resistant strains and thereafter, further disseminated in the environment, including livestock farms. Detection of VRSA in milk is a serious concern as it may further cause health problems in the consumers. This is the first ever report of VRSA in food animals, even though the pathogen is otherwise prevalent in humans.

Research paper thumbnail of Co-infection of methicillin-resistant Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus and extended spectrum β-lactamase producing Escherichia coli in bovine mastitis - three cases reported from India

The Veterinary quarterly, Jan 2, 2014

Emergence of antimicrobial resistance among bovine mastitis pathogens is the major cause of frequ... more Emergence of antimicrobial resistance among bovine mastitis pathogens is the major cause of frequent therapeutic failure and a cause of concern for veterinary practitioners. This study describes intra-mammary infection of methicillin-resistant Staphylococcus epidermidis (MRSE), methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum β-lactamase (ESBL) producing Escherichia coli in two Holstein Friesian crossbred cows with subclinical mastitis and one non-descript cow with clinical mastitis in two different districts of West Bengal, India. In total, three MRSE, one MRSA and three ESBL producing E. coli were isolated from these cases. Both the crossbreds were detected with MRSE (HFSE1 and HFSE2) and ESBL producing E. coli (HFEC1 and HFEC2), whereas, simultaneous infection of three pathogens viz. MRSA (NDSA1), MRSE (NDSE1) and ESBL producing E. coli (NDEC1) was found in the non-descript cow. The methicillin-resistant isolates possessed mecA gene and exhibited resistanc...

Research paper thumbnail of Molecular and phylogenetic characterization of the sieve element occlusion gene family in Fabaceae and non-Fabaceae plants

Previously, we characterized an undocumented strain of Eimeria krijgsmanni by morphological and b... more Previously, we characterized an undocumented strain of Eimeria krijgsmanni by morphological and biological features. Here, we present a detailed molecular phylogenetic analysis of this organism. Namely, 18S ribosomal RNA gene (rDNA) sequences of E. krijgsmanni were analyzed to incorporate this species into a comprehensive Eimeria phylogeny. As a result, partial 18S rDNA sequence from E. krijgsmanni was successfully determined, and two different types, Type A and Type B, that differed by 1 base pair were identified. E. krijgsmanni was originally isolated from a single oocyst, and thus the result show that the two types might have allelic sequence heterogeneity in the 18S rDNA. Based on phylogenetic analyses, the two types of E. krijgsmanni 18S rDNA formed one of two clades among murine Eimeria spp.; these Eimeria clades reflected morphological similarity among the Eimeria spp. This is the third molecular phylogenetic characterization of a murine Eimeria spp. in addition to E. falciformis and E. papillata.

Research paper thumbnail of Molecular and phylogenetic characterization of multidrug resistant extended spectrum beta-lactamase producing Escherichia coli isolated from poultry and cattle in Odisha, India

Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases, 2015

The present study was undertaken to determine the occurrence and characterization of extended spe... more The present study was undertaken to determine the occurrence and characterization of extended spectrum beta-lactamase (ESBL) producing Escherichia coli isolated from cattle and poultry in Odisha, India. Of 316 E. coli isolated from 305 samples (170 fecal samples from poultry and 135 milk samples from cattle), a total of 18 E. coli isolates were confirmed as ESBL producers by combination disc method and ESBL E-test. The isolates were resistant to oxyimino cephalosporins and monobactam as revealed by disc diffusion assay and determination of minimum inhibitory concentration. Resistance against other antibiotics was frequently noted as well. Further, beta-lactamase genes viz., blaSHV, blaCTXM, blaTEM and blaampC were detected in 17, 13, 9 and 2 isolates, respectively in PCR. Of the 18 ESBL strains, 16 were positive for class I integron (int1), nine of them carried sulphonamide resistance gene (sul1) and one harbored quinolone resistance gene (qnrB). Virulence markers for extraintestina...