Investigation of methicillin resistance and Panton-Valentine leukocidin in Staphylococci isolated from bovine mastitis

Background: Mastitis, which is inflammation of the mammary gland, is among the most important diseases in dairy herds resulting in reductions of milk yield and milk quality. Although several groups of microorganisms have been reported as etiological agents of mastitis, Staphylococci are the most frequently isolated bacteria from bovine mastitic milk samples. The aim of this study was to isolate the Staphylococcus species from bovine mastitis, investigate the mecA ve pvl genes in isolated species by PCR and determine the antibiotic resistance of methicillin resistant strains to some antibiotics commonly used in veterinary field. Materials, Methods & Results: In the present study, 972 half-udder milk samples (n = 757 CMT positive, n = 215 CMT negative) were used from 251 lactating cows from 34 different enterprises located center town and villages of Õdemi, zmir. Ten microliters of each milk sample was inoculated onto Columbia blood agar, containing 7% of sheep blood and incubated under aerobic conditions for 24-48 h at 37C. The certain identification of Staphylococcus isolates was achieved using Crystal Identification Systems Gram-Positive ID kit. Bacterial DNAs were extracted from all strains using boiling method and strains were screened for the presence of 16S rDNA, mecA and pvl genes by PCR. The antimicrobial resistance of MRS species was determined by using disc [...](AU)

Investigation of methicillin resistance and Panton-Valentine leukocidin in Staphylococci isolated from bovine mastitis

Background: Mastitis, which is inflammation of the mammary gland, is among the most important diseases in dairy herds resulting in reductions of milk yield and milk quality. Although several groups of microorganisms have been reported as etiological agents of mastitis, Staphylococci are the most frequently isolated bacteria from bovine mastitic milk samples. The aim of this study was to isolate the Staphylococcus species from bovine mastitis, investigate the mecA ve pvl genes in isolated species by PCR and determine the antibiotic resistance of methicillin resistant strains to some antibiotics commonly used in veterinary field. Materials, Methods & Results: In the present study, 972 half-udder milk samples (n = 757 CMT positive, n = 215 CMT negative) were used from 251 lactating cows from 34 different enterprises located center town and villages of Õdemi, zmir. Ten microliters of each milk sample was inoculated onto Columbia blood agar, containing 7% of sheep blood and incubated under aerobic conditions for 24-48 h at 37C. The certain identification of Staphylococcus isolates was achieved using Crystal Identification Systems Gram-Positive ID kit. Bacterial DNAs were extracted from all strains using boiling method and strains were screened for the presence of 16S rDNA, mecA and pvl genes by PCR. The antimicrobial resistance of MRS species was determined by using disc [...]

Occurrence, hemolytic toxins and antimicrobial resistance of Aeromonas hydrophila strains from dairy cow and anatolian water buffalo quarter milk samples in Turkey

Background: Motile aeromonads are considered to be one of the most important food-borne pathogens because of potential human health significance. Aerolysin and hemolysin are virulence factors playing a significant role in the pathogenesis of infections. Antimicrobial resistance is an important problem limiting therapeutic options. The main objective of the present study was to isolate motile Aeromonas species from cow and Anatolian buffalo quarter milk samples and determine the antimicrobial resistance and hemolysin (hlyA) and aerolysin (aerA) virulence genes of isolated species by PCR.Material, Methods & Results: The present study was carried out on apparently healthy 200 dairy cows and 103 Anatolian water buffaloes in different stages of lactation, hand-milked twice a day, held in private farms located in Afyonkarahisar province of Western Turkey. Before milking, 771 and 399 quarter milk samples were collected from cows and Anatolian buffaloes, respectively. For the isolation, APW, SAA and blood agar were used. The certain identification of isolates was made using API 20NE system. The strains were tested for susceptibility to 21 different antibiotics by disc diffusion test. Bacterial DNAs were extracted from all strains using a genomic DNA extraction kit and strains were screened for the presence of hlyA and aerA genes by PCR. While A. hydrophila was isolated from 22 (1.9%) of 1170 quarter milk samples, A. caviae and A. sobria were not detected in the examined milk samples. The isolation rate of A. hydrophila from cow and buffalo milk samples was 2.1% (n = 16) and 1.5% (n = 6), respectively. The highest resistance rate in strains was against ampicillin (100%), followed by ampicillin-sulbactam (95.5%), methicillin (95.5%) and cephazoline (81.8%). The most of strains were also resistant at least to one of the antibiotics.[...](AU)

Occurrence, hemolytic toxins and antimicrobial resistance of Aeromonas hydrophila strains from dairy cow and anatolian water buffalo quarter milk samples in Turkey

Background: Motile aeromonads are considered to be one of the most important food-borne pathogens because of potential human health significance. Aerolysin and hemolysin are virulence factors playing a significant role in the pathogenesis of infections. Antimicrobial resistance is an important problem limiting therapeutic options. The main objective of the present study was to isolate motile Aeromonas species from cow and Anatolian buffalo quarter milk samples and determine the antimicrobial resistance and hemolysin (hlyA) and aerolysin (aerA) virulence genes of isolated species by PCR.Material, Methods & Results: The present study was carried out on apparently healthy 200 dairy cows and 103 Anatolian water buffaloes in different stages of lactation, hand-milked twice a day, held in private farms located in Afyonkarahisar province of Western Turkey. Before milking, 771 and 399 quarter milk samples were collected from cows and Anatolian buffaloes, respectively. For the isolation, APW, SAA and blood agar were used. The certain identification of isolates was made using API 20NE system. The strains were tested for susceptibility to 21 different antibiotics by disc diffusion test. Bacterial DNAs were extracted from all strains using a genomic DNA extraction kit and strains were screened for the presence of hlyA and aerA genes by PCR. While A. hydrophila was isolated from 22 (1.9%) of 1170 quarter milk samples, A. caviae and A. sobria were not detected in the examined milk samples. The isolation rate of A. hydrophila from cow and buffalo milk samples was 2.1% (n = 16) and 1.5% (n = 6), respectively. The highest resistance rate in strains was against ampicillin (100%), followed by ampicillin-sulbactam (95.5%), methicillin (95.5%) and cephazoline (81.8%). The most of strains were also resistant at least to one of the antibiotics.[...]