Israel Medical Association Journal

Background: Staphylococcus aureus infection is a major cause of morbidity and mortality worldwide. Clindamycin is widely used in the treatment of staphylococcal infections; however, it is our impression that in the last few years, inducible clindamycin resistance (ICR) has become more prevalent.

Objective: To assess the prevalence of ICR[1] in methicillin-sensitive Staphylococcus aureus (MSSA) infections among pediatric patients in Israel.

Methods: We reviewed the files of children diagnosed with MSSA[2] infections during the period January 2006 to June 2007 for full antibiogram (including the D-test for ICR), phage typing and randomly amplified polymorphic DNA.

Results: Altogether, 240 MSSA isolates were recovered, mainly from wounds and abscesses. ICR was detected in 62 of 68 erythromycin-resistant/clindamycin-sensitive strains (91%); the ICR rate for the total number of isolates was 26% (62/240). Phage type analysis demonstrated that 38 of 61 ICR isolates

(62%) were sensitive to group 2, compared to 42 of 172 isolates (24%) that did not express ICR (P < 0.01). On randomly amplified polymorphic DNA, phage type 2 isolates expressing ICR belonged to the same clone, which was different from ICR isolates sensitive to other phages and from isolates not expressing ICR.

Conclusions: Inducible clindamycin resistance is common among methicillin-sensitive Staphylococcus aureus in Israeli children. The D-test should be performed routinely in all isolates of MSSA.

Background: Secondary thrombocytosis is associated with a variety of clinical conditions, one of which is lower respiratory tract infection. However, reports on thrombocytosis induced by viral infections are scarce.

Objectives: To assess the rate of thrombocytosis (platelet count > 500 x 10⁹/L) in hospitalized infants with bronchiolitis and to investigate its potential role as an early marker of respiratory syncytial virus infection.

Methods: Clinical data on 469 infants aged ≤ 4 months who were hospitalized for bronchiolitis were collected prospectively and compared between RSV[1]-positive and RSV-negative infants.

Results: The rate of thrombocytosis was significantly higher in RSV-positive than RSV-negative infants (41.3% vs. 29.2%, P = 0.031). The odds ratio of an infant with bronchiolitis and thrombocytosis to have a positive RSV infection compared to an infant with bronchiolitis and a normal platelet count was 1.7 (P = 0.023, 95% confidence interval 1.07–2.72). There was no significant difference in mean platelet count between the two groups.

Conclusions: RSV-positive bronchiolitis in hospitalized young infants is associated with thrombocytosis.