<div>Background: The emergence of a multidrug resistance phenotype is most likely outcome of co-existing multiple mechanisms. The underlying molecular mechanism of carbapenem resistance is poorly understood in bacterial isolates of animal origin. The present study investigates the resistance mechanism for reduced susceptibility to carbapenem in E. coli. 
&nbsp;&nbsp; 
Methods: The study includes 12 multidrug resistant E.coli isolates showing decreased susceptibility to imipenem. Carbapenemase production was evaluated by the mCarba-NP test. The presence of the carbapenem resistance gene was confirmed by multiplex PCR. Efflux pump activity was accessed by broth microdilution method with or without selective efflux pump inhibitor. We analyzed differential expression of the outer membrane porin genes (ompF, ompC) and efflux pump genes (acrA, acrB) by quantitative real-time PCR analysis.&nbsp; 
 
Result: We observed increased expression of acrA and acrB genes in all the E. coli isolates under imipenem stress. A positive correlation (p&lt;0.001) was evident between imipenem MIC and acrA and acrB over-expression in these isolates. A significant decrease in ompF and ompC expression was observed in these isolates under imipenem stress. The change in MIC was not correlated with the corresponding OmpC and OmpF gene expression. The results suggest the importance of efflux pump and porins proteins in the emergence of multidrug resistance besides carbapenemase production.</div>

Imipenem Induced Transcriptional Modulation of Multidrug Efflux Pumps and Porin Genes in Carbapenem Resistant Escherichia coli Isolates of Animal Origin

<div>Background: Antibiotic resistance is an emerging concern in the therapy of clinical infections worldwide. Previous studies conducted in our laboratory have confirmed an increase in the prevalence of extended spectrum beta-lactamase (ESBL) among the Gram-negative bacterial pathogens associated with dogs, which could act as a potential source for the transfer of these resistant pathogens or their genetic determinants to human. Since carbapenems are the last resort drugs against these resistant pathogens, the study was aimed to isolate and characterise carbapenem resistance among Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumoniae) and Pseudomonas aeruginosa (P. aeruginosa) associated with common clinical infections in dogs. 
 
Methods: A total of 100 samples were collected from lesional skin, urine and anterior vagina of dogs presented to the Veterinary Hospitals of Kerala Veterinary and Animal Sciences University at Mannuthy and Thrissur. The samples were cultured onto Brain Heart Infusion Agar (BHIA), Eosin Methylene Blue (EMB) and Mac Conkey (MAC) for isolation of bacteria. Identification of the isolates was performed based on cultural, morphological and biochemical characteristics. The isolates were subjected to antimicrobial susceptibility test (ABST) against the 12 commonly used beta-lactam and non&ndash;beta-lactam group of antibiotics by disc diffusion method and further subjected to screening for ESBL double disc diffusion method. Carbapenem-resistant isolates were subjected to phenotypic confirmatory test for carbapenemase production employing Imipenem-EDTA and Ertapenem-boronic acid minimum inhibitory concentration (MIC) strip method. 
 
Result: Forty four Gram-negative bacterial isolates obtained were viz., E. coli (30), K. pneumonia (11) and P. aeruginosa (3) from the 100 samples. Apart from these, other isolates obtained were Staphylococcus spp. (53) and Bacillus spp. (2). All the Gram-negative isolates were subjected to ABST employing 12 common antibiotics belonging to beta-lactam and non-beta-lactam groups. Multidrug resistance (MDR) could be observed in 28 E. coli, 11 K. pneumoniae and three P. aeruginosa isolates. All the 42 MDR isolates showed positive results for ESBL production. A total of 14 isolates out of the 44 Gram-negative bacilli were found to be resistant to carbapenem either to imipenem, meropenem or ertapenem. Among the 14 Gram-negative isolates, nine turned out to be positive for metallo-beta-lactamase (MBL) and none for K. penumoniae carbapenemase (KPC) on phenotypic confirmatory test for detecting major carbapenemase enzymes. The present study documented that Gram- negative bacteria like E. coli, K. pneumoniae and P. aeruginosa isolated from dogs are showing an increase rate of resistance against carbapenems which are the last resort drugs against ESBL producers. Hence, there is an urgent need to curb the irrational and excessive use of antibiotics in veterinary sector.</div>

<div>Phenotypic Characterisation of Klebseilla pneumoniae Carbapenemase and Metallo Beta-lactamase in Carbapenem Resistant Gram-negative Bacteria</div>

Background: Staphylococcus aureus is capable of producing a wide range of virulence factors. It is a deadly bacterium that is resistant to the majority of antibiotics that are typically provided. The ability of S. aureus to establish chronic, implant associated infections and our inability to cure them, is directly associated with its biofilm formation, creating an environment where bacteria can grow and persist while protected from the host immune response and antibiotic therapy. Antibiotic resistance of S. aureus is widely spreading with low cure rate.&nbsp; 
 
Methods: A total of 62 S. aureus strains were isolated from animal pus, human pus, animal skin, human skin, mastitic milk, normal milk and unprocessed meat samples. The isolates were genotypically confirmed by 23S rRNA ribotyping for S. aureus. Using 14 antibiotics belonging to different generations were tested for their resistance pattern from various sources.&nbsp; 
 
Result: All the mastitic milk, animal pus, human pus and unprocessed meat S. aureus isolates from all the places of sampling showed 100% sensitivity towards imipenem while isolates obtained from mastitic milk, human skin, animal skin showed 100% resistance towards ampicillin and ampicillin+sulbactum combination.

Resilient Staphylococcus aureus in Mastitis Milk: Insights into Antibiotic Resistance and Biofilm Formation

Background: Clinical infections caused by multidrug-resistant pathogenic bacteria are associated with increased morbidity and mortality, imposing a severe economic burden. Pseudomonas aeruginosa, a gram-negative bacterium, had demonstrated a prominent level of acquired antimicrobial resistance to its selective antimicrobials. Currently, there is no updated information about the antimicrobial susceptibility pattern of Pseudomonas aeruginosa in Grenada. Hence, the present study aimed to determine the antimicrobial susceptibility pattern of P. aeruginosa from the clinical isolates of dogs in Grenada. 
 
Methods: This retrospective study used the diagnostic reports from January 2015 to December 2022. The diagnostic microbiology laboratory reports of canine patients at the Small Animal Clinic of St. George&rsquo;s University in Grenada were analyzed to study the antimicrobial susceptibility pattern of P. aeruginosa. 
 
Result: Among the various bacterial clinical isolates, ninety-one clinical samples were positive for P. aeruginosa. The antimicrobial susceptibility test pattern of these isolates revealed susceptibility to gentamicin (95.6 %), ceftazidime (96.7%), imipenem (97.7%) and ciprofloxacin (97.8%). The result of the present retrospective study illustrates that P. aeruginosa isolates from canine patients in Grenada are susceptible to the recommended antimicrobial drugs. However, this study also revealed the recent development of progressive antimicrobial resistance. This mandates the judicious use of antibacterial drugs against bacterial infections in Grenada.

Retrospective Analysis of Antimicrobial Susceptibility Pattern of Pseudomonas aeruginosa from Clinical Samples of Dogs in Grenada, West Indies

The present study describes the prevalence of extended spectrum b-lactamases (ESBL) producing E. coli in raw chevon, milk and human samples in different districts of Chhattisgarh state. A total of 330 samples comprising of chevon (n=126), raw milk (n=104), human urine and stool (n=100) were collected from Bilaspur, Durg, Raipur, Rajnandgaon and Dhamtari districts of Chhattisgarh and processed for isolation of E. coli. The biochemically confirmed E. coli isolates were further screened of for the presence of blaTEM gene by PCR amplification. Analysis of samples indicated an overall prevalence of 31.52%. The highest prevalence of E. coli was recorded in fresh chevon samples (38.09%) followed by human urine samples (37.14%), human stool samples (30%) followed by milk samples (20.19%). In &ndash;vitro antibiotic sensitivity test of E. coli isolates revealed that all isolates to be highly sensitive towards imipenem, gentamicin, ciprofloxacin, amoxyclav, ampicillin, oxytetracyclin. The highest numbers of E. coli isolates were found resistant to erythromycin, cefotaxim, ceftazidime, cephalexin and cifixime. The 49 E. coli isolates were found to have Multiple Antibiotic Resistance (MAR) index more than 0.2, thus indicating indiscriminate use of antimicrobials. The 44 (42.3%) isolates were identified as presumptive ESBL producers and out of them 39.4% isolates were found to harbour the blaTEM gene on their plasmid DNA indicating the presence of multidrug resistant ESBL producing E. coli in foods of animal origin and human samples.

Prevalence and molecular characterization of extended-spectrum b-Lactamases (blaTEM) producing Escherichia coli isolated from humans and&nbsp;foods of animal origin in Chhattisgarh, India

<div>Background: The present study was undertaken to study the percentage of pathogenic bacteria present in different fruit and vegetable samples available in the market in and around Kalaburagi, Karnataka, South India.&nbsp; 
 
Methods: A total of 940 different samples were collected from Kalaburagi, out of which 390 (23.84%) were fruits and 550 (35.27%) were vegetables. The pathogenic bacteria were isolated, by enrichment culture method using peptone water. The bacterial isolates were identified by convention microbial identification procedures.&nbsp; 
 
Result: Antibiotic resistant testing by disc diffusion method performed for E.coli, Salmonella and Shigella. Among the pathogens, E. coli (86.50%) of the isolates were resistant to Nalidixic acid while Imipenem and Trimethoprim-Sulfamethoxazole has the lowest resistance (19.84%), Salmonella (86.66%) isolates were resistant to Ciprofloxacin while Norfloxacin has the lowest resistance (4.76%) and Shigella (80.35%) isolates were resistant to Vancomycin while Amoxicillin has the lowest resistant (3.57%). Multiple drug resistance (MDR) was seen in E. coli at (38.88%), Salmonella at (26.66%) and Shigella at (10.71%) accordingly. The study therefore shown that E.coli, Salmonella and Shigella occur in Fruits and vegetables which collected from market place in Kalaburagi, Karnataka India, As per the results, adequate precaution should be taken while handles these fruits and vegetables. The antimicrobial resistance pattern shown by the isolates is an indication that adequate measurement needs to be taken to regulate the drug use in both humans and animals in order to minimize the risk of increasing antimicrobial resistance.</div>

<div>Microbiological Evaluation and Antibiotic Susceptibility Pattern of Bacterial Isolates Associated with Some Contaminated Edible Fruits and Vegetables</div>

<div style="text-align: justify;">Sub-clinical Mastitis is one of the major problems in India which is among the largest milk producing countries in the world, hampering national economy. Among 422 bovine milk samples screened from different cattle farms of West Bengal with history of infection and drop in milk yield by on-spot bromothymol blue (BTB) test, 371 samples were considered for collection and secondary screening by somatic cell count study. The collected milk samples showed significantly high average SCC value of 3.26-4.88 lakh cells/ml of milk which was indicative of infection. Samples (23, 6.53%) were found to be positive for Pseudomonas sp. showing distinct bluish-green pigmentation on cetrimide agar, typical results on morphological and in biochemical characterization. Presence of 19 (5.39%) Pseudomonas aeruginosa isolates were confirmed by fluorescent technique for detection of characteristic blue-green fluorescence by the pigment pyoverdin. PCR of these positive isolates revealed that 11 isolates were positive for toxA and 6 isolates for exoS genes with 2 isolates possessing both the genes. In Mice pathogenicity test, highest fatality (100%) was shown by the isolates with both the genes followed by isolates with toxA (66.67%) and exoS (41.67%) respectively with successful re-isolation of P. aeruginosa from the dead mice. Post-mortem examination of the dead mice showed marked haemorrhages on liver, blackish discoloration of intestines and haemorrhages on lungs. Antibiogram revealed that the isolates were highly sensitive to drugs like amikacin (89.47%), imipenem (84.21%), meropenem (78.95%) and cefoperazone-sulbactam (84.21%) but resistant to tetracycline (68.42%), piperacillin (63.16%), oxacillin (52.63%), mecilinam (47.37%) and others.</div>

<div style="text-align: justify;">Mice pathology study of toxA and exoS genes bearing Pseudomonas aeruginosa isolated from bovine Sub-clinical mastitis in West Bengal with their Antibiogram</div>

Background: The use of antimicrobials in food animals significantly contributes to the development of antimicrobial resistance in nature. This study aimed to determine the prevalence of ESBL-producing E. coli isolated from cattle, buffalo, sheep and goat fecal samples.&nbsp; 
 
Methods: In this study out of 2025 healthy animals from 10 different farms, fecal samples were randomly collected by rectal swabs from 200 animals (50 each from cattle, buffalo, sheep and goat). E. coli was isolated and further studied for AMR and ESBL production by phenotypic assays and PCR targeting ESBL genes.&nbsp; 
 
Result: The overall prevalence of E. coli was 81.50% with the highest isolation rate from cattle and goat samples. Out of 163 isolates, 45.39% were ESBL-producers. Genes encoding beta-lactam resistance viz. blaSHV, blaTEM, blaCTX-M and blaOXA were detected in 44.59% ESBL-positive isolates. The blaSHV was present in only cattle isolates, while blaCTX-M was present in E. coli isolated from all animals. The prevalence of beta-lactam genes was found as blaSHV (2.70%), blaTEM (12.16%), blaCTX-M (22.97%) and blaOXA (6.75%). A high degree of resistance to multiple antimicrobials was observed. Maximum susceptibility of E. coli was observed for trimethoprim, imipenem and chloramphenicol. This study demonstrated that food animals could be the source of ESBL-producing multidrug-resistant E. coli. The present findings are significant in the context of AMR monitoring in India.

Phenotypic and Molecular Characterization of Escherichia coli Isolated from Food Animals for Antimicrobial Resistance&nbsp;

Background: Saum is a very important traditional food item of the Mizo society in Mizoram, North East India; but there is scanty scientific study and reports on Saum. The present study has been conducted to study and compare the prevalence of E. coli in Saum from three different storage places such as storage/keeping Saum under the sun (24-38&deg;C) during hot part of the day, inside the refrigerator (3-4&deg;C) and near the cooking fire (30-50&deg;C) at home.&nbsp; 
 
Methods: The study was conducted from May, 2022 to November, 2022. A total of 105 Saum samples were collected from three different storage places comprising of 35 samples from each storage places and then analysed for the presence of foodborne pathogen E. coli and it&rsquo;s virulence genes (stx1, stx2, elt, est genes) by conventional method and PCR. All the E. coli isolates were subjected to 12 different antibiotics for antimicrobial resistance pattern by disc diffusion method. 
 
Result: The overall prevalence of E. coli from 105 samples was 7.62% (8/105) comprising of 5.71% (2/35) from the storage place under the sun, 2.86% (1/35) from the refrigerator and 14.29% (5/35) near the cooking fire and no presence of virulence genes of E. coli was detected in the present study. The antimicrobial resistance pattern of all the 8 E. coli isolates showed the highest resistance to Cefazolin (100%) followed by Imipenem (37.5%). The present work will be a complementary contribution among Mizo society to know the best and safest storage places of Saum in regards to public health point of view.&nbsp;

Comparative Study on the Prevalence of Escherichia coli and it&rsquo;s Antibiogram in Saum from Three Different Storage Places in Household at Mizoram

<div>Background: Among enterobacteria E. coli and Klebsiella spp. are of great concern in health care settings, as these bacteria sometimes may contaminate the milk due to unhygienic practices and poor udder condition which have been associated with various illnesses. Therefore, this study aimed to detect the carbapenem resistant E. coli and Klebsiella spp. of bovine milk origin with regard to the risk of human transfer via the food chain in community. 
 
Methods: Total 240 samples were collected from Ayodhya and Sultanpur districts of Eastern Plain Zone of Uttar Pradesh (India). Confirmation of E. coli and Klebsiella spp. isolates was done by using species specific uidA and 16S rRNA gene, respectively. Then, carbapenemase positive E. coli and Klebsiella spp. were confirmend by DDST, MBL E-strip test and PCR analysis by targeting (bla-NDM, bla-OXA-48 and bla-KPC). Antibiogram of all carbapenemase positive isolates was performed against 20 antibiotics of 12 different classes. 
 
Result: In the present study, total 74(30.83%) isolates were identified including 55(22.92%) E. coli and 19(7.92%) Klebsiella spp. by PCR, out of which 12(16.21%) isolates were confirmed as carbapenemase producers comprising 7(12.72%) E. coli and 5(26.31%) Klebsiella spp by DDST and E-strip. All carbapenemase positive E. coli were found 100% sensitive to polymyxin-B and chloramphenicol, while all Klebsiella spp. were 100% sensitive to amikacin and polymyxin-B. Resistance against imipenem, meropenem, cefotaxime, cefpodoxime, ceftazidime, ceftriazone, aztreonam and ampicillin ranged between 80.0%-100%. All carbapenemase positive isolates were found multidrug resistant. Carbapenemase genes bla-NDM and bla-KPC were detected in E. coli while bla-OXA-48 and bla-KPC were detected in Klebsiella spp.</div>

​Detection of Carbapenemase Genes (bla-NDM, bla-KPC, bla-OXA-48) in Escherichia coli and Klebsiella species, Isolated from Milk Samples of Bovine in Eastern Plain Zone of Uttar Pradesh

Imipenem Induced Transcriptional Modulation of Multidrug Efflux Pumps and Porin Genes in Carbapenem Resistant Escherichia coli Isolates of Animal Origin

Phenotypic Characterisation of Klebseilla pneumoniae Carbapenemase and Metallo Beta-lactamase in Carbapenem Resistant Gram-negative Bacteria

Resilient Staphylococcus aureus in Mastitis Milk: Insights into Antibiotic Resistance and Biofilm Formation

Retrospective Analysis of Antimicrobial Susceptibility Pattern of Pseudomonas aeruginosa from Clinical Samples of Dogs in Grenada, West Indies

Prevalence and molecular characterization of extended-spectrum b-Lactamases (blaTEM) producing Escherichia coli isolated from humans and foods of animal origin in Chhattisgarh, India

Microbiological Evaluation and Antibiotic Susceptibility Pattern of Bacterial Isolates Associated with Some Contaminated Edible Fruits and Vegetables

Mice pathology study of toxA and exoS genes bearing Pseudomonas aeruginosa isolated from bovine Sub-clinical mastitis in West Bengal with their Antibiogram

Phenotypic and Molecular Characterization of Escherichia coli Isolated from Food Animals for Antimicrobial Resistance

Comparative Study on the Prevalence of Escherichia coli and it’s Antibiogram in Saum from Three Different Storage Places in Household at Mizoram

Detection of Carbapenemase Genes (bla_-NDM, bla_-KPC, bla_-OXA-48) in Escherichia coli and Klebsiella species, Isolated from Milk Samples of Bovine in Eastern Plain Zone of Uttar Pradesh