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The value of PCR method in the species-level identification of a mucoid Salmonella sp. Strain isolated from the urine culture of a case with asymptomatic nephrolithiasis   
Yazarlar
Fulya Bayindir Bilman
Diyarbakir Training and Research Hospital, Turkey
Elçin Günaydin
Etlik Veterinary Control Center Institute, Turkey
Mine Turhanoǧlu
Diyarbakir Training and Research Hospital, Turkey
Ali Akkoç
Diyarbakir Training and Research Hospital, Turkey
Özet
Colonies of the Salmonella strains usually show a smooth (S) character. Therefore, Salmonella strains producing mucoid colony are very rarely encountered in the literature. Identification of the mucoid Salmonella strains to the species level is difficult via conventional methods, since the mucus layer does not allow the bacterium to respond to the antigenic reactions. In this study we aimed to emphasize the identification of Salmonella serotypes by the polymerase chain reaction PCR when rough (R) or mucoid (M) Salmonella isolates are encountered in the laboratory. The urine culture of a 17-year-old female patient revealed growth of 100.000 cfu/mL gram-negative bacilli in mucoid colony morphology. The isolate was identified as Salmonella sp. by biochemical tests and Vitek 2 (bioMérieux, France) automated identification system. Agglutination tests showed negative reaction with the known antiserums. Absence of agglutination was attributed to the mucoid character of the isolate. Identification of the Salmonella sp. was confirmed by Vitek MS MALDI-TOF (bioMérieux, France) analysis method, however, the serotype of the strain could not be identified. In order to verify that the mucoid colony was Salmonella spp., species-specific PCR was performed using invA primers, and Salmonella sp. identification was verified by observing a 284 base-pair (bp) PCR amplicon. Subsequently, serogrouping was done by multiplex-PCR (mPCR), which could identify the O:B (O:4), O:C1 (O:7), O:C2-C3 (O:8), O:D (O:9, O:9,46, O:9,46,27), and O:E (O:3,10, O:3,19) somatic antigens. It was detected that the mucoid Salmonella sp. formed a band of approximately 615 bp in size and took place in group D. Another mPCR directed towards O:D1(O:9) and O:E1(3,10) somatic antigens to detect subgroups of group D mucoid Salmonella spp., revealed that the isolate formed a DNA band of approximately 624 bp in size and took place in group D1 which is usually isolated from human. Modified version of another mPCR was used to determine phase-1 flagellar antigen of common Salmonella serovars, as well as to determine the phase-1 flagellar antigen of mucoid Salmonella spp. in group D1. Thus, the isolate was serotyped as Salmonella Enteritidis (1.9,12:g,m:-). Antibiotic susceptibility test performed by disc diffusion method in line with the recommendations of CLSI, revealed that the isolate was susceptible to ampicillin, ciprofloxacin, ceftriaxone, trimethoprim- sulfamethoxazole and chloramphenicol. In conclusion, PCR is a reliable and rapid alternative method that contributes to the conventional serotyping of Salmonella when rough or mucoid strains that lack somatic and flagellar antigens, are isolated.
Anahtar Kelimeler
Mucoid salmonella | Polymerase chain reaction | Salmonella enteritidis
Makale Türü Özgün Makale
Makale Alt Türü SCOPUS dergilerinde yayımlanan tam makale
Dergi Adı Mikrobiyoloji Bulteni
Dergi ISSN 0374-9096
Makale Dili İngilizce
Basım Tarihi 01-2014
Cilt No 48
Sayı 1
Sayfalar 151 / 159
BM Sürdürülebilir Kalkınma Amaçları
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