Detecting Gram-positive anaerobic cocci directly from the clinical samples by multiplex polymerase chain reaction in odontogenic infections.

PURPOSE: Gram-positive anaerobic cocci (GPAC) can be isolated as pathogens from odontogenic infections. Culturing GPAC is time consuming and labor intensive. The objectives of the present study were to examine the utility of polymerase chain reaction (PCR) in directly detecting the presence of GPAC in clinical samples obtained from patients with odontogenic infections and to compare the distribution of GPAC in infected and healthy tissue. MATERIALS AND METHODS: In the present case-control study, the infected tissue from patients and oral mucosal swabs from healthy control subjects were subjected to anaerobic culture and direct PCR analysis for the presence of GPAC. The McNemar, chi-square, and Fisher exact tests and kappa analysis were used for the statistical analyses. P < .05 was regarded as significant. RESULTS: The patient group included 13 men and 14 women, including 9 patients diagnosed with granulation of tooth extraction, 6 with impacted tooth follicles, 4 with peri-implantitis, 3 with abscesses, 2 with epithelial cysts, 2 with infected cysts, and 1 with an oroantral fistula. The control group included 14 men and 12 women. All the patient and control samples contained at least 1 GPAC. The groups did not differ by method of determining GPAC presence, but more microorganisms were detected when clinical samples were directly used for PCR analysis than when cultured bacteria were used (P = .001). CONCLUSIONS: The presence of GPAC in infected tissue cannot be directly related to the development of odontogenic infections. PCR performed directly on clinical material is a sensitive and specific method that can detect GPAC and save time.

[Comparison of different primers used for the genotyping of Candida albicans clinical isolates by randomly amplified polymorphic DNA method]. / Candida albicans klinik izolatlarinin "randomly amplified polymorphic DNA" yöntemiyle genotiplendirmesinde kullanilan farkli primerlerin karsilastirilmasi.

Candida albicans causes severe infections with high mortality rates especially in immunocompromised patients. The aim of this study was to evaluate the efficiency of randomly amplified polymorphic DNA (RAPD) method and compare the discriminatory powers (DP) of different primers used for genotyping Candida albicans isolates. A total of 109 C. albicans strains recovered from throat, sputum, blood, feces, urine, vagina and wound cultures of 65 hospitalized paediatric patients with haematologic malignancy were evaluated by RAPD method using 10 different primers (OPE-03, OPE-04, OPE-12, OPE-18, OPE-19, OPE-20, OPF-10, OPF-12, P1 and P2) between June 1999-April 2003. Strains were separated into groups by analyzing band patterns derived from each primer and the DP was calculated. Reproducibility of the method was determined by evaluating randomly chosen 20 isolates with the same and different PCR devices under the same PCR conditions. C. albicans isolates generated 1-16 bands and were grouped in 41-80 genotypes depending on the primers used. DP of the RAPD method was calculated as > or = 0.90 for each primer (range between 0.90-0.99), which were accepted as reliable values. However, the strains clustered in the same group when studied with a primer could be dispersed into different groups by another primer. The reproducibility of the method was poor and the comparison of band patterns was difficult especially in isolates which generated many bands. In conclusion, for obtaining reliable results by RAPD method, using more than one primer and comparative analysis of these primers are appropriate. RAPD is an adequate method for studying small outbreaks in which a few number of isolates are evaluated, but it is laborious and unreliable for many number of isolates recovered in a long time period because of its poor reproducibility and difficulties in evaluating the strains generating many bands.