Serotype distribution of Streptococcus pneumoniae strains in the nasopharynx of healthy Turkish children.

BACKGROUND & OBJECTIVE: There is scanty information available on the pharyngeal carriage of Streptococcus pneumoniae and serotype distribution in healthy Turkish children. We therefore undertook this study to determine the serotype prevalence of pharyngeal S. pneumoniae isolates of healthy school children in Turkey. METHODS: Pharyngeal swabs were collected from 1440 healthy children (Ages 6-13) between April 2003 and March 2004. S. pneumoniae was identified by standard microbiological culture methods. The serotyping was performed and penicillin minimal inhibitory concentration was detected by the E test. RESULTS: S. pneumoniae carrier rate was 13.9 per cent (n=201) and penicillin resistance 12.9 per cent (n=26). Twenty four of 201 (11.9%) isolates were found intermediately resistant and 2 of 201 (1%) highly resistant by E test. A total of 169 of 201 (84%) pneumococcal isolates were typable with the available antisera. The six most frequent serotypes were 6, 19, 1, 23, 20 and 17. The majority of penicillin-resistant isolates were serotypes 20, 23, 14, 6 and 19. INTERPRETATION & CONCLUSION: The serotype distribution of the isolates showed diversity and that some common circulating serotypes are invasive. A majority of invasive serotypes are covered by pneumococcal conjugate vaccine formulations in at risk groups of children suggesting that vaccine use could reduce the incidence of invasive pneumococcal disease.

Detection of Entamoeba histolytica/Entamoeba dispar in stool specimens by using enzyme-linked immunosorbent assay

Entamoeba histolytica actually comprises two genetically distinct but morphologically indistinguishable species. E. histolytica can cause invasive intestinal and extra intestinal disease, while E. dispar cannot. Identification and differentiation of E. dispar and E. histolytica in stool sample by microscopy is imprecise. Several weeks of culture and isoenzyme analysis are required to differentiate E. histolytica from E. dispar. In this study, we have used an enzyme-linked immunosorbent assay (ELISA) for detection of E. histolytica/E.dispar and compared it with microscopy. Eighty-eight samples were evaluated, trichrome staining was positive in 20.4 percent (18) and ELISA was positive in 29.5 percent (26). Both tests were positive in 14 (15.9 percent) samples, 4 (4.5 percent) only with direct microscopy, and 12 (13.6 percent) only with ELISA. Both tests were negative in 58 (65.9 percent) samples. Microscopy has low sensitivity and high specificity, low negative predictive value and high positive predictive value in comparison with ELISA. E. histolytica/E. dispar antigen detection ELISA tests are inexpensive compared to the specific tests, yield objective results and do not require experienced microscopists and can therefore be recommended for screening of stools worldwide and the results can be taken for treatment that are fitting with its clinic.