Staphylococcus aureus is a common causative agent of bovine mastitis in dairy herds worldwide. This study was designed to assess the prevalence of mastitis in cows through screening tests and molecular characterization of Staphylococcus aureus strains. Out of 175 randomly screened cows, mastitis was detected in 50 cows by California Mastitis Test (CMT), and from those mastitic cows, 200 quarter milk samples were collected for subsequent culture and PCR based identification. The herd, cow and quarter level prevalence of mastitis was 73.3, 28.6 and 29.5% respectively, and subclinical mastitis (SCM) was the predominant type in all cases. According to bacteriology the overall prevalence of herd, cow and quarter level Staphylococcus aureus mastitis was 72.7, 74.0 and 62.0%, respectively, and the pathogen was mostly associated with clinical mastitis (CM). Cows breed, parity, daily milk yield, regular teat dipping, and dry cow therapy were significantly associated (P < 0.05) risk factors for mastitis onset. This study identifies 145 Staphylococcus aureus isolates which varied greatly with the categories of mastitis (higher in CM), udder quarter location (highest in right rear quarters), and to a lesser extent in the study areas (P < 0.05). Antimicrobial susceptibility testing revealed that 79.3% Staphylococcus aureus strains were resistant to at least one antimicrobial, 49.0% to two or more antimicrobials, and clinical isolates showed more resistance to all tested antibiotics. The highest resistance rate was found to oxytetracyclin, and no resistance to ceftriaxone and azithromycin. Seven enterotoxin gene profile were detected in the tested isolates, and mecA was found in 20.0% isolates indicating the emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA). The isolates were carrying genes in combination, and were found higher in SCM cases. In this study, plasmids (>23 kb to 2.9 kb) were detected in 70.3% strains, and 54.9% plasmid bearing strains were multiple drug resistant (MDR). Thus, the high prevalence of Staphylococcus aureus mastitis is an important concern for diary industry of Bangladesh since the strains of this pathogen is becoming more resistant to commercially available antimicrobials, and this is an alarming concern for both animal and public health.
Bacteriological examination on intestinal swabs of 30 apparently healthy and 30 sick / dead Sonali chickens (Fayoumi hen à RIR cock), aged between 25 to 60 weeks were carried out to determine the enteropathogens associated with health and disease, during the period from March to October 2003. These birds of either sex and reared under semi-scavenging system under the SLDP-2 project area in the district of Feni. The 60 swabs were collected at slaughter / necropsy in sterile nutrient and tetrathionate broth. In addition, the gross tissue changes of the sick / dead birds were recorded. The prevalent bacterial flora in intestinal swabs were Salmonella (33.33%), E. coli (95.0%), Staphylococcus (51.66%), Streptococcus (40%) and Pasteurella multocida (3.33%) of which Salmonella (36.66%) and E. coli (26.66%) were associated with marked pathological lesions. The isolated enteropathogens and their associated gross and histopathological changes are described and discussed. It may be concluded from this study that the enteric bacteria usually remain as clinically overt infection and do not produce clinical disease unless or until other factors are involved. Key words: Enterobacteria; apparently healthy chickens; sick/dead chickens; pathology doi: 10.3329/bjvm.v2i1.1928 Bangl. J. Vet. Med. (2004). 2 (1) : 15-21
The Present study was performed in the Department of Pathology, BAU, Mymensingh during the period from January to December 2004. The study was conducted to determine the occurrence and pathology of pullorum disease, fowl typhoid and salmonellosis (paratyphoid infection) in dead chickens at necropsy in Mymensingh district of Bangladesh. A total of 70 samples (liver, ovary and intestine) were collected for isolation of bacteria in different media, and identification was performed based on the staining, cultural and biochemical properties of Salmonella spp. Routine histopathological method was used for the detection of tissue level alterations in Salmonella infected cases. Grossly, in all the infected cases the liver was enlarged and congested and in few cases, liver discoloration with focal necrosis. Old raised hemorrhages in the caecal tonsil and congested deformed ova were other important findings. There was catarrhal inflammation in the intestine. Microscopically, the section of livers showed congestion, hemorrhages, focal necrosis with infiltration of mononuclear cells. The pulmonary lesions consisted of sero-fibrinous exudation with mononuclear cell infiltration. The intestinal mucosa exhibited congestion, hemorrhages and infiltration of plasma cells, heterophils and macrophages. . Out of 70 samples, 8 isolates were identified as Salmonella (11.42 %). Of them, five isolates were identified as Salmonella gallinarum, causative agent of fowl typhoid, one isolate was characterized as Salmonella pullorum, causative agent of pullorum disease and other two motile salmonella were identified as paratyphoid infection.
The present study was conducted to determine the seroprevalence of Salmonella infections in poultry. This study covered cultural prevalence with isolation and identification of the causal agent and pathological lesions in different organs produced by Salmonella in layer farms of Mymensingh district during July-December 2007. The materials were blood samples, liver and cloacal swabs from live and dead birds. The used methods were whole blood agglutination test by commercially available Salmonella antigen kit, culture in different media, Gram's staining, motility test, basic 5 sugar fermentation test and histopathology. The overall seroprevalence was 45.9% in live bird and the rate of seroprevalence decreased with advancement of age of birds. The cultural prevalence in seropositive group was 71% and in seronegative group was 59%. In dead bird, the cultural prevalence in liver was 64% and from cloaca 57%. A total 160 isolates were characterized, among them 64.2% were Salmonella Pullorum, 22.3% were Salmonella Gallinarum and 13.5% were Paratyphoid group of Salmonellae. Pathologically friable, bronze color liver with focal necrosis, various grades of enteritis, and hemorrhagic and congested egg follicles with stalk formation were found. Microscopically, focal necrosis and degeneration with leukocytic infiltration in liver, inflammatory cells in the mucosa and submucosa of intestine were found. In egg follicles, congestion and hemorrhages with leukocytic infiltration were found. The isolated Salmonella organisms may be used for further research such as serotyping, vaccine production and antibiotic sensitivity test.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.