Efficacy of Saccharomyces cerevisiae Fermentation Product and Probiotic Supplementation on Growth Performance, Gut Microflora and Immunity of Broiler Chickens.

Concern for global health security and the environment due to the emergence of antibiotic-resistant bacteria and antibiotic residues in meat and other livestock products has led many countries to restrict the use of antibiotics in animal feed. This experiment was performed to assess the impact of dietary supplementation of a probiotic (Bacillus subtilis) and a postbiotic (Saccharomyces cerevisiae fermentation product) on growth performance, carcass traits, blood haemato-biochemical profile, gut microflora, gut morphology, and immune response in broilers as an alternative to antimicrobials in poultry production system to minimize the effect on global health security. A total of 324 one-day-old Ven Cobb 400 broiler chicks were randomly divided into three dietary groups, each containing 12 replicated pens, and each replicate contained nine chickens. The dietary groups consisted of (1) a basal diet without any growth promoters (T1), (2) the basal diet augmented with Bacillus subtilis at 200 g/MT feed (T2), and (3) the basal diet supplemented with Saccharomyces cerevisiae fermentation product at 1.25 kg/MT feed (T3). To calculate body weight gain, all birds and residual feed were weighed on a replicated basis on days 0, 7, 14, 21, 28, 35, and 42; mortality was recorded daily. At the end of the trial (42 d), two chickens from each replicate were slaughtered for carcass traits, gut microflora, and morphology measurements. Blood samples were collected for the haemato-biochemical profile on 35 d and antibody titer on 28 d and 35 d. Feeding with SCFP (T3 group) significantly improved average daily feed intake (ADFI) and average daily gain (ADG) of chickens compared to the T1 (control) and T2 (probiotic) groups from 1 to 14 days of age. Feed conversion ratio (FCR) was significantly improved in SCFP-fed birds (T3) relative to the control (T1) over the entire experimental period. Carcass traits and blood haemato-biochemical parameters remained unaffected by any diets. However, cholesterol levels and concentrations of corticosterone were significantly lower in T3 compared to T2 and T1 groups. Total E. coli, Enterohaemorrhagic E. coli, ESBL-producing Enterobacteriaceae, and Salmonella counts were significantly lower in T2 and T3 groups compared to T1 group and Salmonella counts were lower in T3 when compared to T2. However, there was no significant difference in Lactobacillus count among treatment groups. A significant increase in villi height and villi-height-to-crypt-depth ratio (VH: CD) was observed in both T3 and T2 groups. On day 28, the T3 and T2 groups exhibited a significant increase in antibody titers against Newcastle disease virus and infectious bursal disease virus. It can be concluded that Saccharomyces cerevisiae fermentation product and Bacillus subtilis probiotic could be viable alternatives to antimicrobials in poultry production considering beneficial impacts in broilers fed an antibiotic-free diet.

Molecular characterization of Myxoboluscatmrigalae (Myxosporea: Myxobolidae) infecting the gill lamellae of carp Cirrhinusmrigala (Hamilton).

The present study attempted sequencing the 18S rRNA gene of Myxoboluscatmrigalae infecting the gill lamellae of carp, Cirrhinusmrigala and compared its genetic homology and phylogenetic characteristics with 18S rRNA genes of other Myxobolus spp. The infected fish had up to 3 small, creamy white plasmodia per gill filament with 30-50 spores each. The spore size was 17.90 ± 0.70 × 7.40 ± 0.40 µm. The sporoplasm contained two large nuclei of size 0.57 ± 0.09 µm and no iodinophilous vacuole. The DNA sequence of M.catmrigalae was clustered phylogenetically with other Myxobolus spp. infecting the gills of cyprinids available in GenBank, which showed 77-87 % homogeneity. On the phylogenetic tree, M.catmrigalae (KC933944) was clustered with M.pavlovskii (HM991164) infecting the gill lamellae of silver carp, Hypophthalmichthysmolitrix. The species most closely related to M.catmrigalae in GenBank was M.pavlovskii (AF507973) infecting the gill lamellae of big head carp, Aristichthysnobilis with 87 % homogeneity. This is the first report on molecular characterization of gill lamellae infecting M. catmrigalae.

Molecular characterization of Argulus bengalensis and Argulus siamensis (Crustacea: Argulidae) infecting the cultured carps in West Bengal, India using 18S rRNA gene sequences.

The present study characterized Argulus spp. infecting the cultured carps using 18S rRNA gene sequences, estimated the genetic similarity among Argulus spp. and established their phylogenetic relationship. Of the 320 fish samples screened, 34 fish (10.6%) had Argulus infection. The parasitic frequency index (PFI) was observed to be high (20%) in Hypophthalmichthys molitrix and Labeo bata. The frequency of infection was high in September (PFI: 17%) and October (PFI: 12.9%). The 18S rRNA sequences of five A. bengalensis (KF583878, KF192316, KM016968, KM016969, and KM016970) and one A. siamensis (KF583879) of this study showed genetic heterogeneity and exhibited 77-99% homology among the 18S rRNA gene sequences of Argulus spp. of NCBI GenBank database. Among the Indian Argulus spp. the sequence homology was 87-100%. Evolutionary pair-wise distances between Indian Argulus spp. and other Argulus spp. ranged from 0 to 20.20%. In the phylogenetic tree, all the crustaceans were clustered together as a separate clade with two distinct lineages. The lineage-1 comprised exclusive of Branchiura (Argulus spp.). All Argulus bengalensis clustered together and A. siamensis (KF583879) was closely related to Argulus sp. JN558648. The results of the present study provided baseline data for future work on population structure analysis of Indian Argulus species.

The phylogenetic position of Myxoboluscarnaticus (Myxozoa, Myxosporea, Bivalvulida) infecting gill lamellae of Cirrhinus mrigala (Hamilton, 1822) based on 18S rRNA sequence analysis.

Myxozoans are an economically important group of microscopic parasites best known for the diseases they cause in commercially important fish hosts. The classification of myxosporeans is generally based on the morphology of their myxospores. Without molecular data, it is very difficult to identify new or existing species. DNA sequence information is therefore, a prerequisite to taxonomic and phylogenic studies of myxosporeans. In the present study, a myxozoan parasite, Myxobolus carnaticus, infecting the gill lamellae of mrigal carp, Cirrhinus mrigala, was characterized by the 18S rRNA gene sequence. The DNA sequence of M. carnaticus clustered phylogenetically with other gill infecting Myxobolus spp. of freshwater clades, forming a dichotomy with closely related M. pavlovskii (HM991164) that infects the gill lamellae epithelium of silver carp, Hypophthalmichthys molitrix with 95% similarity. Evolutionary pair-wise distances among M. carnaticus and other species of myxosporeans indicated high genetic diversity among myxosporeans. The present study demonstrated that tissue tropism, host specificity and habitat play important roles in phylogenetic relationships among myxozoan species.

Detection of picobirnavirus and rotavirus in diarrhoeic faecal samples of cattle and buffalo calves in Mumbai metropolis, Western India.

In this study 113 diarrhoeic faecal samples obtained from buffalo (n = 68) and cattle (n = 45) calves under 1 years of age were analysed in order to determine the presence of rotavirus infection and the frequency of picobirnavirus excretion. Eleven (9.73%) samples positive for group A rotavirus were identified through RNA-polyacrylamide gel electrophoresis (RNA-PAGE), while 4 (3.53%) samples showed a bisegmented genome with a typical picobirnavirus pattern. This is the first report of picobirnavirus in cattle and buffalo calves from Western India.

Serotyping, pathogenicity and antibiogram of Escherichia coli isolated from raw poultry meat in West Bengal, India.

This study has been undertaken to isolate and characterise Escherichia coli strains from raw poultry meat in West Bengal, determine their pathogenicity and identify the prevalent serotypes and their antibiogram. A total of 83 raw poultry meat samples were collected from February to July 2004. Thirty-three samples (39.76%) were positive for E. coli. The majority of highly pathogenic E. coli belonged to O3, O6, O25, O73, O120 whereas the highly enteropathogenic E. coli belonged to O6, O25, and O158. Most isolates (84% - 100%) were sensitive to chloramphenicol, amikacin and gentamicin, they were (92% - 100%) also resistant to novobiocin, cefixime, sulphafurazole, vancomycin. Considering the frequency of E. coli serogroups O6, O25, O158 which are important zoonotic pathogens, special attention needs to be paid in order to maintain strict hygienic measures in the retail meat shops, so to avoid serious health risks for the retailers and for the consumers.

Determination of bovine rotavirus G serotype by polymerase chain reaction.

A total of 113 diarrheic samples comprising of 68 buffalo calves and 45 cow calves were screened by RNA-PAGE for the detection of presence of rotavirus. RNA-PAGE analysis of these samples revealed 11 (9.73%) was found positive for rotavirus. Out of 68 faecal samples of buffalo calves tested for viral gastroenteritis, 8 (11.76%) were found positive for rotavirus. Similarly, out of 45 faecal samples of cattle calves tested for viral gastroenteritis, 3 (6.66%) was found positive for rotavirus. Rotavirus-positive samples represented long electropherotype. All RNA-PAGE-positive faecal samples for rotavirus subjected to RT-PCR for VP7 gene, ten samples yielded a specific product of 1,013 bp of VP7 gene. All the PCR-positive samples of the present study were subjected to genotyping with primers for G6, G8 and G10 genotype. All positive samples showed G10 genotype. This indicates that G10 may be predominant genotype among bovine calves in Mumbai region in India.