Profiling of Antimicrobial Resistance Genes and Integron from Escherichia coli Isolates Using Whole Genome Sequencing.

This study is designed to investigate Escherichia coli for the antibiotic resistance genes (ARGs) and integrons from healthy as well as diarrhoeic/diseased animals/birds' faecal samples. A total of eight samples were selected for the study; from each animal, two samples were taken, one from healthy animals/birds and one from diarrhoeic/diseased animals/birds. Antibiotic sensitivity testing (AST) and whole genome sequencing (WGS) was performed for selected isolates. The E. coli isolates showed resistance to moxifloxacin, followed by erythromycin, ciprofloxacin, pefloxacin, tetracycline, levofloxacin, ampicillin, amoxicillin, and sulfadiazine (4/8, 50.00% each). The E. coli isolates were 100% sensitive to amikacin, followed by chloramphenicol, cefixime, cefoperazone, and cephalothin. A total of 47 ARGs from 12 different antibiotic classes were detected among the eight isolates by WGS. The different classes of antibiotics included aminoglycoside, sulphonamide, tetracycline, trimethoprim, quinolone, fosfomycin, phenicol, macrolide, colistin, fosmidomycin, and multidrug efflux. The class 1 integrons were detected in 6/8 (75.00%) isolates with 14 different gene cassettes.

Significance of Limosilactobacillus fermentum and Saccharomyces cerevisiae on the Growth Performance, Haematological Traits, Serum Biochemistry, Faecal and Caeca Microbiota of Broiler Chickens.

OBJECTIVE: The aim of the study was to supplement Lactobacillus and yeast in broiler feed by replacing immunomodulators to develop antibiotic free meat and egg production by analyzing broiler performance, haematological traits, serum biochemistry, histopathology, fecal bacterial count, and metagenomic analysis of broiler ceca. METHOD: Two cultures i.e. KGL4 (Limosilactobacillus fermentum MTCC 25515) and WBS2A (Saccharomyces cerevisiae GI: MG101828) were considered for the evaluation of Broiler chicken's health and growth during 42 days study without supplementing immunomodulators and commercial probiotics in poultry feeds. The 96-day-old broiler chickens were grouped into: T1 [Control: basal diet + immunomodulatory factor and commercial probiotic], T2 [Basal diet without immunomodulatory factor and commercial probiotic + KGL4 (108 CFU/mL), T3 [Basal diet without immunomodulatory factor and commercial probiotic + WBS2A (107 CFU/mL), and T4 [Basal diet without immunomodulatory factor and commercial probiotic + KGL4 + WBS2A in a 1:1 ratio] (Institutional Animal Ethics Committee (IAEC) No. 365/PRS/2022). The following parameters, i.e., body weight gain, feed consumption ratio (FCR), white blood cell count (WBC), red blood cell count (RBC), hemoglobin content, platelet count, cholesterol content, triglycerides, high density lipoprotein (HDL), very low-density lipoprotein (VLDL), fecal counts and metagenomic analysis of broiler ceca samples, were measured. RESULTS: In the study, amongst various traits, the overall performance of the group treated along with Limosilactobacillus fermentum (KGL4) showed improved results as compared to control group. Limosilactobacillus fermentum (KGL4) treated group had higher body weight gain (2583.04 ± 35.421 g), FCR (1.60 ± 0.019), WBC (235.60 ± 2.562 × 103/µL), hemoglobin content (14.10 ± 0.442 g/dl), and HDL (131.40 ± 11.400 mg/dl). The investigation did not show significant variations in the relative proportions of genus or phylum among various groups during metagenomic analysis of ceca samples. There was also an improvement in haematological traits; no evidence of necrosis in heart, intestine and liver tissues. CONCLUSIONS: The present study conclude that it is safe to feed Limosilactobacillus fermentum and Saccharomyces cerevisiae to broilers as feed supplements and also supports the current knowledge regarding the use of yeast and lactic acid bacteria as an effective alternative stimulant for maintaining health and growth of broiler chickens.