Browsing by Author "Arabaci, Cigdem"

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Detection and Comparison of Neuraminidase Activities in Human and Bovine Group B Streptococci
(Wiley-blackwell, 2016) Ekin, Ismail Hakki; Gurturk, Kemal; Ilhan, Ziya; Ekin, Suat; Borum, Ayse Ebru; Arabaci, Cigdem; Yesilova, Abdullah
Human and bovine group B streptococcus (GBS) isolates were serotyped and amounts of released N-acetylneuraminic acid from N-acetylneuraminyl-lactose by extracellular neuraminidase were colorimetrically assessed. According to serotyping by co-agglutination method, 30 of bovine GBS and 43 of human GBS could be serotyped (ST) by monospecific antisera coated with protein A. The remaining GBS strains were designated as nontypeable (NT). The released N-acetylneuraminic acid was determined in 90.9% of bovine GBS and 47.1% of human GBS isolates. The differences between the total bovine and human GBS isolates were statistically significant (p < 0.001). In comparison with detected N-acetylneuraminic acid level in bovine and human groups, significant decrease was observed in the bovine NT group according to increased human NT (p < 0.01) and bovine ST groups (p < 0.01). However, N-acetylneuraminic acid level in bovine ST and bovine total groups significantly (p < 0.001) increased with respect to the human ST group and human total group. Neuraminidase activity was detected more frequently in bovine GBS isolates. Considerable differentiations were observed between typeable and nontypeable isolates.
Detection of Enzyme Activities and Their-Relation To Serotypes of Bovine and Human Group B Streptococci
(Soc General Microbiology, 2015) Ekin, Ismail Hakki; Gurturk, Kemal; Ilhan, Ziya; Arabaci, Cigdem; Gulaydinl, Ozgul
Enzymatic properties of group B streptococci (GBS) serotypes from bovine milk and human routine vaginal specimens were investigated. Out of the 56 human and 66 bovine GBS, 35 and 30 could be classified serologically by a co-agglutination test with type-specific antisera, respectively. Hyaluronidase (HYAL), streptokinase (SK) and protease activities were detected using culture media. HYAL activity was observed mostly in typable human GBS, and serotypes la, lc and II comprised 77.3 % of the typable strains producing HYAL. Bovine GBS serotypes II, III and VII comprised 87.5 % of typable bovine strains exhibiting HYAL activity. SK activity was detected only in three human GBS. Human GBS serotypes la, lc, II, III, VII and almost all typable bovine GBS strains showed protease activity. beta-D-glucosidase activity was frequently observed in human GBS, whereas N-acetyl-beta-D-glucosaminidase activity was mostly detected in non-typable GBS from humans. These results indicate that different GBS serotypes could vary in their virulence properties, and bovine and human GBS isolates could not be differentiated by their enzyme activities. Use of the culture media appeared to be a simple-to-apply and useful method for the detection of extracellular enzyme activity such as HYAL, protease and SK.
Phenotypic and Genotypic Characterization of Macrolide-Lincosamide Resistance in Staphylococcus Aureus Isolates From Bovine and Human
(Sciendo, 2023) Gulaydin, Ozgul; Gurturk, Kemal; Ekin, Ismail Hakki; Ilhan, Ziya; Arabaci, Cigdem
In this study, penicillin, oxacillin, and macrolide-lincosamide-streptogramin (MLS) resistance in S. aureus strains that were isolated from bovine mastitis cases, and human patients were investigated. Inducible clindamycin resistance (iML) was not found in 30 bovine isolates, while it was detected in 3 (10%) of 30 human isolates. MIC90 values of penicillin, oxacillin and macrolide-lincosamides (ML) were 2, 0.19, > 256 mu g/ml in bovine isolates and were 3, 3 and 0.19-1.5 mu g/ml in human isolates, respectively. Streptogramin resistance was not found in both bovine and human isolates. Although the mecA gene was detected in all of the oxacillin resistant isolates, blaZ gene could not be detected in penicillin resistant isolates. The erm(B) gene was detected in 5 (38.6%) of 13 ML-resistant bovine isolates, and the mph(C) gene was detected in 2 (66.66%) of 3 human isolates. As a result, resistance to penicillin and oxacillin was found to be higher in human S. aureus isolates, while ML resistance was found to be higher in bovine isolates in this investigation. It was concluded that the presence of genes in extra-chromosomal elements associated to penicillin and macrolide resistance should be investigated. The data obtained from this study will contribute to the studies on antimicrobial susceptibility in the field of human and veterinary medicine.