BACKGROUND: The present analysis focuses on phenotypic and genotypic characterizations of efflux-mediated erythromycin resistance in Streptococcus pneumoniae due to an increase in macrolide resistance in S. pneumoniae worldwide. METHODS: We investigated the prevalence of efflux-mediated erythromycin resistance and its relevant genetic elements from 186 specimens of S. pneumonia isolated from clinical and normal flora from Tehran, Iran. The presence of erythromycin resistance genes was tested by PCR with two sets of primers, specific for erm(B) and mef(A/E), and their genetic elements with tetM, xis, and int genes. Isolates were typed with the BOX PCR method and tested for resistance to six antibiotics. RESULTS: Antibiotic susceptibility tests revealed that 100% and 47% isolates were resistant to tetracycline and erythromycin, respectively. The erythromycin and clindamycin double-disc diffusion test for macrolide-lincosamide-streptograminB (MLSB) resistance phenotype showed 74 (84%) isolates with the constitutive MLSB phenotype and the remaining with the M phenotype. BOX PCR demonstrated the presence of 7 types in pneumococci with the M phenotype. Fourteen (16%) isolates with the M phenotype harbored mef(A/E), tetM, xis, and int genes. CONCLUSIONS: The present results suggest dissemination of polyclonal groups of S. pneumoniae with the M phenotype carrying resistance genes attributed to transposon 2009.
Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/genetics ; DNA, Bacterial/metabolism ; Drug Resistance, Multiple, Bacterial/*genetics ; Erythromycin/*pharmacology ; Genotype ; Humans ; Microbial Sensitivity Tests ; Phenotype ; Pneumococcal Infections/microbiology/pathology ; Polymerase Chain Reaction ; Streptococcus pneumoniae/*drug effects/*genetics/isolation & purification ; Tetracycline/pharmacology

OBJECTIVETo study the clinical characteristics of Streptococcus pneumonia-associated hemolytic uremic syndrome (SP-HUS) in children.

METHODClinical and laboratory data of a pediatric case of SP-HUS were retrospectively analyzed and the key points of diagnosis and therapy were reviewed.

RESULTAn 18-month old girl was admitted with chief complaint of fever and cough for 5 days combined with mild labored breath. Breath sound was found weakened in right lung with lower lobe dullness on percussion. Laboratory tests revealed: WBC 3.7×10(9)/L, Hb 83 g/L, PLT 11×10(9)/L, C-reactive protein (CRP) > 180 mg/L. Morphological study of the RBCs showed marked anisocytosis and schistocytosis. Urinalysis showed 42.66 RBCs per high-power field, occult blood (+++), proteinura (++++). Streptococcus pneumoniae was isolated from blood, pleural fluid and sputum. Serotyping with simplified chessboard system was 3. The direct Coombs test was positive. Serum complement levels (C3 and C4) were depressed at 0.699 g/L, 0.064 g/L, respectively. Chest X-ray showed pleural effusion and infection of the right hemothorax. The computerized tomographic scan of the chest revealed pneumatoceles in the right lower lobe. The diagnosis on admission we considered was SP-HUS. Intravenous antibiotic therapy (vancomycin + cefoperazone/sulbactam) was administered. The renal replacement theraphy was administered to maintain electrolyte and fluid balances and adequate nutrition. Transfusions of washed red blood cells were administered to correct the anemia. One month after admission the patient was good with recovery. Liver and renal function recovered and the pneumonia was resolving, anemia and platelets were corrected. The direct Coombs test turned to be negative. Serum complement levels (C3 and C4) were normal. After 3-month follow-up, no clinical anomalies were detected.

CONCLUSIONSP-HUS should be suspected when the following occurs in the context of pneumococcal infections: microangiopathic hemolytic anemia, thrombocytopenia, acute renal failure and a positive Coombs test result. Serotype 3 of SP was associated with HUS.

Anti-Bacterial Agents ; therapeutic use ; Biomarkers ; analysis ; Coombs Test ; Female ; Hemolytic-Uremic Syndrome ; diagnosis ; etiology ; microbiology ; therapy ; Humans ; Infant ; Lung ; diagnostic imaging ; pathology ; Pleural Effusion ; etiology ; Pneumococcal Infections ; complications ; Radiography ; Retrospective Studies ; Serotyping ; Streptococcus pneumoniae ; classification ; isolation & purification