African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5236

Full Length Research Paper

Serotype distribution and antimicrobial resistance of invasive Streptococcus pneumoniae isolates from children in Zahedan, Iran

Mohammad Bokaeian1*, Hossein Ali Khazaei2 and Mani Javadimehr3
1Research Center for Zahedan Infectious Diseases and Tropical Medicine, Zahedan University of Medical Sciences, I. R. Iran. 2Department of Immunology and Hematology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran. 3Department of Medical English, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.
Email: [email protected]

  •  Accepted: 05 December 2011
  •  Published: 09 January 2012

Abstract

Streptococcus pneumoniae is the leading cause of death among children worldwide. This study was conducted to evaluate the antibiotic resistance patterns and seroepidemiology of invasive S. pneumoniae isolates in children of Zahedan. Invasive isolates of S. pneumoniaewere obtained from normal sterile sites (blood, cerebrospinal fluid, pleural fluid, joint aspirate, peritoneal fluid and pericardial fluid) of pediatric patients (aged ≤14 years) from 3 large hospitals in Zahedan, Iran. The serotyping was carried out by latex agglutination test and the minimum inhibitory concentrations (MIC) of penicillin, as well as other commonly used antibiotics were determined by broth dilution method. During February 2008 to November 2010, a total of 1265 children with suspected invasive bacterial disease were recruited, of whom 75 (5.9%) were identified to have S. pneumoniae as the causative agent of invasive disease. The leading serotypes were 23F, 6B, 3, 19F and 14 (70.7% of all isolates). Intermediate- and high-level resistance, were observed in 37.3 and 45.4% of isolates respectively. Resistance was also demonstrated against erythromycin (90.7%), cotrimoxazole (80.0%), tetracycline (66.6%), cefuroxime (62.7%), imipenem (17.3%) and amoxicillin/clavulanate (9.2%). All the isolates were susceptible to vancomycin and levofloxacin. Multiple drug resistance was observed mostly in types 19F, 23F, 6B and 14. The application of heptavalent pneumococcal conjugate vaccine (PCV7) covered 68.0% of all IPD cases, 42.7% of the penicillin-nonsusceptible S. pneumoniae (PNSSP), and 48.0% of the multiple drug resistant (MDR) isolates. The highest PNSSP prevalence and highest PCV7 coverage were in children aged <2 years. Antibiotic resistance was common among invasive isolates of S. pneumoniae in Zahedan. The present study suggests that the introduction of anti-pneumococcal conjugate vaccines into immunization programme would likely lead to a significant reduction of IPD- associated morbidity among children in Zahedan.

Key words: Antimicrobial resistance, invasive pneumococcal disease, serotype, Streptococcus pneumoniae.