Therapeutic potential of cristobalite in the treatment of calf diarrhea

Calf diarrhea continues to be the major problem of calves in the neonatal period. The effect of zeolites has been increasingly studied in ruminant health in recent years. In the present study, the efficacy of cristobalite, a zeolite, in neonatal calf diarrhea was studied first time. For this purpose, twenty-five neonatal calves with diarrheas were divided into two groups, and Group 1 (n=12) received conventional treatment and Group 2 (n=13) received cristobalite (Zoosorb 10 mg/kg) orally 3 times a day in addition to conventional treatment. Escherichia coli k99 and CS31a, bovine rotavirus and bovine coronavirus were isolated from fecal samples at the beginning of the treatment, on the third day and before discharge. It was determined that the recovery period in Group 2 was 0.95 (20.6%) days shorter than in Group 1 (p⟨0.05) while no viral agents were found on the fifth day in Group 2, viral shedding continued in 4 of 5 calves in Group 1. In conclusion, the study revealed that cristobalite speeds the recovery time and possibly decreases viral shedding in neonatal calf diarrhea, demonstrating a remarkable efficiency in the treatment.

Determination of antibiotic resistance profiles and biofilm production of Staphylococcus spp. isolated from Anatolian water buffalo milk with subclinical mastitis

Mastitis is one of the most crucial diseases of dairy animals. Especially subclinical mastitis (SCM) has negative impacts on of dairy economy in term of reducing milk quality and quantity also premature culling and cost of therapy. Staphylococci are important etiological agents in SCM. The aim of the study was to investigate the biofilm production and antibiotic resistance profiles of Staphylococcus spp. other than S. aureus isolated from milks of Anatolian water buffalo with subclinical mastitis. Twenty-two coagulase negative staphylococci (CNS) identified phenotypically were also identified with PCR as Staphylococcus spp. other than S. aureus. Biofilm productions were investigated both by Congo Red Agar Method and PCR. The antibiotic resistance profiles of the isolates were determined by Disc Diffusion Method and they were antibiotyped. Only three (13.6%) isolates were biofilm positive both phenotypically and genotypically. All isolates except for two were resistant against at least two antibiotics. Multidrug-resistance among the isolates was low (13.6%). Antibiotyping results showed that the similarities among the strains were between 30-100%. Genotyping of the strains revealed that a genetic heterogeneity was found among CNS isolates and their similarities were between 43% and 93%. In conclusion, CNS isolates identified as subclinical mastitis agents in buffaloes showed a high antibiotic resistance profile especially against oxacillin and vancomycin. Further studies should be conducted to investigate new mechanisms and/or genes responsible for antibiotic resistance in buffaloes.

Molecular analysis and genotyping of methicillin-resistant Staphylococcus aureus strains isolated from different clinical sources

Background

Investigating genetic relatedness between methicillin-resistant Staphylococcus aureus (MRSA) strains from humans and different animal species may clarify the epidemiological characteristic of MRSA infections together.

Aim

The aim of the study was to perform genotypic characterization and type strains of MRSA isolated from different clinical sources, by molecular techniques.

Materials and Methods

The molecular characterization of the strains was performed by polymerase chain reaction (PCR), using several specific oligonucleotides. These were as follows: S. aureus species-specific sau gene, mecA gene coding PBP2a responsible for methicillin resistance, femA gene coding for a protein, which influences the level of methicillin resistance of S. aureus, and is universally present in all MRSA strains; spa gene coding for protein A; coa gene coding for coagulase, and blaZ gene coding for the production of beta-lactamase. To determine the genetic diversity of these strains, random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was performed.

Results

Among the 415 S. aureus strains, 61 were phenotypically identified as MRSA, and confirmed as S. aureus by amplification of sau gene. However, 90.16% of the strains were mecA positive, while all were negative for femA gene. The presence and polymorphism of coa and spa genes were investigated and 83.60% and 18.03% strains were positive for coa and spa, respectively. While these strains were grouped into six coa-types by PCR, no polymorphism was found for spa gene among strains having only single 190 bp of the band. bla genes were found in 75.40% of strains. These strains were divided into 12 RAPD types.

Conclusions

The results showed the relatively high heterogeneity and variation of coa gene among MRSA strains, while further studies on sequencing of these strains may identify which sequence type is predominant in this region.