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Volume 4, Issue 1 (4-2010)
Abstract Background and objectives: Colonization of nasopharynx by Streptococcus Pneumoniae can lead to pneumococcal disease. This study was performed to determine the carriage rate of nasopharyngeal S.pneumoniae in adolescents and their antibiotic susceptibility and serotype prevalence in Zahedan, Iran Material and Methods: Nasopharyngeal specimens were obtained from 865 adolescents aged 10-19 years old of eight schools in Zahedan and then assessed by standard procedures to isolate S. Pneumoniae. The serotyping was carried out by latex agglutination test, the minimum inhibitory concentration (MIC) of penicillin, as well as other commonly used antibiotics, was determined by a broth-dilution method. Results: Pneumococci were Isolated from 15.7% [136/865, 95% confidence interval (CI) 12.3-18.9] of total samples. Of 136 samples, 119 isolates are typified by the available antisera which the most frequent ones are 1, 19A, 15C, 9V, 11A and 19F. Ninthythree pneumococcal isolates are sensitive to penicillin. The MIC values of antibiotics tested are (μg/ml): penicillin 0.01-4, cefotaxime 0.01-4, ceftriaxone 0.02-128, chloramphenicol 0.08-32, ciprofloxacin 0.06-16, erythromycin 0.01-128, tetracycline 0.08- 128 and vancomycin 0.02-1. Conclusion: A clear diversity is seen in the serotype distribution of the S. Pneumoniae isolates and most of the antibiotic resistant strains belonge to a few serotypes. Healthy adolescents in Zahedan commonly show pneumococcal carriage and antibiotic resistance. Keywords: Streptococcus Pneumoniae, nasopharyngeal carriage, penicillin resistance, serotype
Volume 8, Issue 5 (1-2015)
Abstract Background and Objective: Increased antibiotic resistant strains and inadequacy of current vaccines against pneumococcal infections necessitate the study of novel protein antigens. It seems that minor autolysin of Streptococcus pneumoniae may have antigenicity. Thus, we aimed at cloning its gene for the first time. Material and Methods: After DNA extraction of Streptococcus pneumoniae (ATCC 49619), Specific primers were designed for amplifying minor autolysin gene fragment, using PCR. The purified gene fragment was inserted into pET21a vector and was transformed into bacterial competent cells by heat shock technique. The presence of gene and absence of mutation in the recombinant vector were checked out with sequencing and enzymatic digestion methods. The gene sequence was finally analyzed by bioinformatic tools. Results: The gene of minor autolysin was cloned successfully and the result of enzymatic digestion was the indication of complete isolation of this gen from plasmid. . Bioinformatics studies revealed that the mature protein was lacking signal peptide and the gene encoded 318 amino acids with a molecular weight of 36.4 kDa. Conclusion: The presentation and characterization of novel antigens such as minor autolysin could help us with finding new approaches for preventing and controlling pneumococcal infection. Keywords: Streptococcus Pneumoniae, Minor Autolysin, Cloning
Volume 10, Issue 6 (11-2016)
ABSTRACT
Background and Objective: Streptococcus pneumoniae is one of the leading causes of death among children worldwide. Nasopharyngeal colonization in children can spread pneumococcal infections in the community. This study aimed to evaluate the prevalence of S. pneumoniae strains isolated from healthy pharyngeal carriers less than 5 years of age.
Methods: This cross-sectional descriptive study was performed on 150 children under 5 years old in the city of Shiraz. After nasopharyngeal swab sampling, the samples were cultured on blood agar containing 5% sheep blood. The cultures were incubated at 37 °C for 24 h. Primary identification was carried out using optochin sensitivity testing, bile solubility testing and gram staining. Molecular identification of S. pneumoniae strains was done using lytA gene-specific primers.
Results: Of the 150 samples collected from healthy children, 24.67% were pharyngeal carriers of S. pneumoniae. The highest frequency of pneumococcal strains was related to male carriers (n= 22, 59.46%) and the children aged 1-2 years (n=11, 29.73%). The results showed no significant association between the prevalence of pharyngeal carriage and gender or age.
Conclusion: Given the increasing rate of pharyngeal carriage of S. pneumoniae in children as a risk factor for respiratory tract infections, there is a need for further monitoring of the circulating serotypes and investigation of antibiotic-resistance mechanisms.
Keywords: Streptococcus Pneumoniae, Pharyngeal Carriers, lytA.
ABSTRACT
Background and Objective: Streptococcus pneumoniae is one of the leading causes of death among children worldwide. Nasopharyngeal colonization in children can spread pneumococcal infections in the community. This study aimed to evaluate the prevalence of S. pneumoniae strains isolated from healthy pharyngeal carriers less than 5 years of age.
Methods: This cross-sectional descriptive study was performed on 150 children under 5 years old in the city of Shiraz. After nasopharyngeal swab sampling, the samples were cultured on blood agar containing 5% sheep blood. The cultures were incubated at 37 °C for 24 h. Primary identification was carried out using optochin sensitivity testing, bile solubility testing and gram staining. Molecular identification of S. pneumoniae strains was done using lytA gene-specific primers.
Results: Of the 150 samples collected from healthy children, 24.67% were pharyngeal carriers of S. pneumoniae. The highest frequency of pneumococcal strains was related to male carriers (n= 22, 59.46%) and the children aged 1-2 years (n=11, 29.73%). The results showed no significant association between the prevalence of pharyngeal carriage and gender or age.
Conclusion: Given the increasing rate of pharyngeal carriage of S. pneumoniae in children as a risk factor for respiratory tract infections, there is a need for further monitoring of the circulating serotypes and investigation of antibiotic-resistance mechanisms.
Keywords: Streptococcus Pneumoniae, Pharyngeal Carriers, lytA.
ABSTRACT
Background and Objective: Streptococcus pneumoniae is one of the leading causes of death among children worldwide. Nasopharyngeal colonization in children can spread pneumococcal infections in the community. This study aimed to evaluate the prevalence of S. pneumoniae strains isolated from healthy pharyngeal carriers less than 5 years of age.
Methods: This cross-sectional descriptive study was performed on 150 children under 5 years old in the city of Shiraz. After nasopharyngeal swab sampling, the samples were cultured on blood agar containing 5% sheep blood. The cultures were incubated at 37 °C for 24 h. Primary identification was carried out using optochin sensitivity testing, bile solubility testing and gram staining. Molecular identification of S. pneumoniae strains was done using lytA gene-specific primers.
Results: Of the 150 samples collected from healthy children, 24.67% were pharyngeal carriers of S. pneumoniae. The highest frequency of pneumococcal strains was related to male carriers (n= 22, 59.46%) and the children aged 1-2 years (n=11, 29.73%). The results showed no significant association between the prevalence of pharyngeal carriage and gender or age.
Conclusion: Given the increasing rate of pharyngeal carriage of S. pneumoniae in children as a risk factor for respiratory tract infections, there is a need for further monitoring of the circulating serotypes and investigation of antibiotic-resistance mechanisms.
Keywords: Streptococcus Pneumoniae, Pharyngeal Carriers, lytA.
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