<div>Background: Mastitis is the most common and economically important disease of dairy cattle. Subclinical mastitis is a more important form in India than clinical mastitis. Subclinical mastitis (SCM) detection done by periodic examination of the udder health by evaluation of milk at the herd level or the individual cow level by milk somatic cell count (SCC), followed by culture of random milk samples. The presented study was undertaken by survey and sampling of milk from lactating crossbred cattle of unorganized dairy farms and farmer&rsquo;s dairy of the peri-urban region of middle Indo-Gangetic Plains. The objective of the study was to monitor the status of SCM in crossbred cattle and associated changes in milk constitutes and oxidative stress in milk.&nbsp; 
 
Methods: A total of 147 lactating crossbred cattle were screened for SCM using the modified California Mastitis Test (CMT) using detergent based CMT reagent and compared with conventional CMT reagent, followed by SCC, milk constituents, bacterial isolation and antibiotic sensitivity testing (ABST). General information was collected in pre-tested questionnaire. The data obtained were statistically treated to evaluate significance of the study. 
 
Conclusion: The overall prevalence of subclinical mastitis in peri-urban cross-bred cattle was 36.74% which varied with parity and stage of milking. Prevalence of subclinical mastitis was highest (55.77%) in cross-bred cattle in mid-lactation and Parity 3-5. The mean SCC was significantly higher (7.21&plusmn;0.27) in subclinical mastitis compared to CMT negative (3.66&plusmn;0.06) milk sample. Somatic cell count was positively and significantly correlated with CMT reactions using conventional CMT reagent (rs= 0.86) as well as modified CMT reagent (rs=0.815) attempted using Spearman rank-order correlation coefficient. The mean values of milk pH, fat and lactic acid acidity increased significantly (P&le;0.01) in SCM compared to the milk of healthy cattle, except lactose which decreased significantly in SCM milk. The common contagious bacteria responsible for SCM isolate were coagulase-positive Staphylococcus spp. (64.82%) isolates from these SCM milk followed by Streptococcus spp. ABST test conducted on random CMT positive milk sample indicated that gentamicin as most sensitive, followed by enrofloxacin. The present finding indicates the suitability of enrofloxacin as the most useful antibiotic for the treatment of subclinical mastitis in cross-bred cattle of the peri-urban area of middle Indo-Gangetic plains.</div>

Status of Subclinical Mastitis in Crossbred Cattle of Peri-urban Unorganized Herd of Middle Indo-gangetic Plains

<div>Background: A study was carried out to screen milk borne Staphylococcus aureus for resistance against Beta lactam antibiotics.&nbsp; 
 
Methods: A total of 45 milk samples were collected over a period of three months from large animal outpatient unit of Madras Veterinary College Hospital, Chennai. Upon collection of samples, ABST followed by its growth in Mannitol Salt Agar was carried out as part of the phenotypic screening. Genotypic screening for Staphylococcus screening was done with the help of PCR by using nuc &nbsp;and mec A primers. MIC for ceftriaxone and cloxacillin was carried out with the samples that were found positive for Staphylococcus aureus. The antibiotic sensitivity pattern is presented: Fluoroquinolones (87.5% sensitive), aminoglycosides (72.5% sensitive), Amoxicillin-Clavulanic acid (Amoxyclave) (72.5% sensitive). The MSA positive samples were subjected to molecular identification with the help of PCR.&nbsp; 
 
Result: The results revealed 10 samples positive for Staphylococcus aureus and 5 among them positive for mecA gene. The MIC results were as follows: MIC50-10.95&micro;g/ml and MIC90- 87.510.95&micro;g/ml for ceftriaxone and MIC50- 43.75 &micro;g/ml and MIC90- 87.5&micro;g/ml for cloxacillin, indicating emergence of resistance. However, further studies are required in a larger sample size that can help us to attain more conclusive results.</div>

<div>Screening of Milk Borne Staphylococcus aureus for Resistance against Beta Lactam Antibiotics</div>

<div>Background: In the current scenario, the emergence of antimicrobial resistance has made it difficult to treat bacterial infections alone using antibacterial agents. 
 
Methods: Milk samples collected from 100 mastitis affected cows from August 2018 to June 2019 and were stored at 4&deg;C. After species confirmation, isolates were subjected to ABST and screened for resistance genes - mecA, blaTEM using PCR. Minimum Inhibitory Concentration (MIC) of tetracycline and ampicillin were determined against both Staphylococcus spp and E. coli, alone and in combination with atorvastatin, vitamin D by using a modified microdilution method.&nbsp; 
 
Result: Staphylococcus and E. coli isolates showed 80.65% and 85.71%, 100% and 85.71% resistance against tetracycline and ampicillin, respectively. Atorvastatin and vitamin D did not display antibacterial effects as sole agents against both bacterial species. However, there was a significant decrease in the MIC of ampicillin against E. coli and Staphylococcus spp when combined with atorvastatin and vitamin D but not for tetracycline.</div>

Effect of Atorvastatin and Vitamin D against Multi-drug Resistant Staphylococcus spp and Escherichia coli Isolated from Bovine Mastitis Cases

<div>Background: Antimicrobial resistance (AMR) is a rising concern in the global aquaculture sector due to the rampant prophylactic use of antibiotics. This study is aimed to determine the AMR pattern in freshwater ornamental fishes.&nbsp; 
 
Methods: Fish pathogens were isolated and identified from infected Guppy and Molly collected from ornamental fish farms. Antibiotic susceptibility testing (ABST) using disc diffusion with 36 antibiotics was performed following the disc diffusion method. The resistance gene cassettes such as Class 1 and Class 2 integron were also detected from resolved isolates.&nbsp; 
 
Result: Fish pathogens were isolated and identified as Aeromonas hydrophila, A. dhakensis, A. veronii, A. sobria, Bacillus subtilis, Comamonas testosteroni, Edwardsiella tarda, Enterobacter cloacae, Enterococcus faecalis, Kurthia gibsonii and Klebsiella aerogenes. Shannon Weiner diversity index of resolved isolates was found to be 1.366 and 2.101 for Guppy and Molly, respectively. ABST results showed an elevated resistance pattern for A. veronii, E. faecalis (Guppy), K. aerogenes, B. subtilis, E. faecalis, C. testosteroni (Molly) with higher multiple antibiotic resistance indexes (&gt;0.33). Meanwhile, all the recovered isolates were susceptible to sulphafurazole, enrofloxacin, norfloxacin and ciprofloxacin. Detection of class 1 integron in genomic and plasmid DNA reminds the rapid spread of the AMR gene through horizontal gene transfer.</div>

Prevalence, Antimicrobial Resistance and Resistance Gene Cassettes Detection in Bacterial Pathogens Isolated from Freshwater Ornamental Fishes

Background: The aim of current study was to investigate the probiotic potential of autochthonous Lactobacillus species against pathogenic Escherichia coli in poultry.&nbsp;&nbsp; 
 
Method: A total of 73 samples were collected from cloacal swabs and tissues of desi and commercial chicken. The Lactobacillus were isolated based on cultural, biochemical and molecular teats. The probiotic potency was tested in vitro and antimicrobial activity and ABST was carried by Agar well diffusion and disc diffusion methods, respectively. Nucleotide sequencing was done by Sanger sequencing. Haemolysis and gelatin hydrolysis assays were used as safety testes.&nbsp; 
 
Result: From 73 cloacal swabs and tissues of desi and commercial chicken, 56 Lactobacillus were isolated of which 22 showed high autoaggregation and hydrophobicity potential. Based on survivability at acidic pH (2.5) and bile concentrations (0.5%), 16 isolates were selected and were subjected to well diffusion assay against pathogenic E. coli. All the isolates showed zone of inhibition against E. coli ranging from 10 -18 mm. ABST revealed that all the isolates are sensitive to chloramphenicol, ampicillin and erythromycin and 75% of the isolates were resistant to streptomycin, gentamicin and vancomycin. Only one isolate out of 16 tested was non hemolytic and none of the isolates tested positive for gelatine hydrolysis. Sequencing result of selected isolate revealed 96.82% of its similarity to Lactobacillus fermentum.&nbsp;&nbsp;

Probiotic Potential of Autochthonous&nbsp;Lactobacillus&nbsp;against Avian Pathogenic&nbsp;Escherichia coli&nbsp;

<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: In aquaculture, antibiotic misuse has accelerated antimicrobial resistance (AMR), endangering fish health, ecosystems and public safety. Probiotics offer a sustainable alternative by enhancing immunity, growth and pathogen resistance without promoting AMR. The pearlspot (Etroplus suratensis), a valuable brackish water fish in South Asia, remains vulnerable to bacterial diseases, yet research on autochthonous probiotics for its health management is limited. 
 
Methods: The present investigation aimed to assess the probiotic potential of two bacterial isolates, Bacillus subtilis (BLCET3/SRLAAH/2023) and B. velezensis (BLCET4/SRLAAH/2023) isolated from the gut of a brackish water fish, E. suratensis. The probiotic potential of the isolates was analyzed by in vitro assays, molecular analysis of probiotic marker genes and in vivo biosafety assay. 
 
Result: Among the two isolates, BLCET3 exhibited stronger antimicrobial activity against Streptococcus agalactiae, Aeromonas veronii and Enterococcus sp. Both BLCET3 and BLCET4 tolerated a pH range of 2-9 and bile salt concentrations up to 10%, produced extracellular enzymes and formed biofilms. BLCET3 showing significantly higher (P&lt;0.05) auto-aggregation, co-aggregation and cell surface hydrophobicity. Neither isolate displayed antibiotic resistance in ABST assays and in vivo biosafety tests confirmed them as non-pathogenic. PCR analysis revealed the presence of key probiotic marker genes. These findings confirm the probiotic potential of both isolates for aquaculture applications. 
&nbsp;

In vitro Profiling of Probiotic Bacillus Species Isolated from the Gut Microbiota of Brackish Water Fish, Etroplus Suratensis (Pearlspot)

Status of Subclinical Mastitis in Crossbred Cattle of Peri-urban Unorganized Herd of Middle Indo-gangetic Plains

Screening of Milk Borne Staphylococcus aureus for Resistance against Beta Lactam Antibiotics

Effect of Atorvastatin and Vitamin D against Multi-drug Resistant Staphylococcus spp and Escherichia coli Isolated from Bovine Mastitis Cases

Prevalence, Antimicrobial Resistance and Resistance Gene Cassettes Detection in Bacterial Pathogens Isolated from Freshwater Ornamental Fishes

Probiotic Potential of Autochthonous Lactobacillus against Avian Pathogenic Escherichia coli

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

In vitro Profiling of Probiotic Bacillus Species Isolated from the Gut Microbiota of Brackish Water Fish, Etroplus Suratensis (Pearlspot)