Editorials

Continuing medical education in obstetrics and gynaecologyThe present and future of obstetrics and gynaecology in South AfricaThe case for an increased tobacco tax in South AfricaImplications of bacterial resistance for the use of beta-lactam agents in clinical practiceQuality of care - and debateAlcohol and brain damag

Corynebacterium group D2 urinary tract infection

An unusual multiply resistant corynebacterium was isolated from the urine of a comatose patient. This organism was resistant to sulphafurazole, trimethoprim, nalidixic acid, cefazolin, nitrofurantoin, clindamycin, erythromycin, oxacillin, penicillin, gentamicin, amikacin, cinoxacin, ceftazidime and ceftazidime, but was susceptible to ciprofloxacin, ofloxacin, norfloxacin, vancomycin and fucidin. It was identified as the first reported isolate in South Africa of corynebacterium group D2, an organism recently implicated in alkaline-encrusted cystitis and urinary tract infection. We discuss the case history of the patient and review the literature

Clarithromycin alone and in combination with ceftriaxone inhibits the production of pneumolysin by both macrolide-susceptible and macrolide-resistant strains of Streptococcus pneumoniae

Objectives To investigate the effects of clarithromycin (0.01–0.5 mg/L) alone or in combination with ceftriaxone (0.1 and 0.25 mg/L) on pneumolysin production by both macrolide-susceptible and -resistant [2 erm(B) positive and 2 mef(A) positive] strains of Streptococcus pneumoniae. Methods The bacteria were cultured for 6 h at 37°C/5% CO2 in tryptone soy broth, washed, enumerated and resuspended to 0.5–3 × 108 cfu/mL in tissue culture medium, RPMI 1640. After 16 h of incubation at 37°C / 5% CO2, pneumolysin was assayed in the bacteria-free supernatants, as well as in lysates, using a functional assay based on the influx of calcium into human neutrophils. Results Exposure of not only macrolide-susceptible strains, but also the macrolide-resistant strains, of S. pneumoniae to sub-MICs of clarithromycin resulted in dose-related inhibition of the pneumolysin production, whereas production of the toxin was unaffected by ceftriaxone. Conclusions These observations demonstrate that even in the setting of macrolide resistance the production of pneumolysin, a key virulence factor of the pneumococcus, is attenuated by exposure of this microbial pathogen to clarithromycin

Emergence of levofloxacin-non-susceptible Streptococcus pneumoniae and treatment for multidrug-resistant tuberculosis in children in South Africa: a cohort observational surveillance study

Background: Use of fluoroquinolones to treat paediatric cases of multidrug-resistant tuberculosis could affect the emergence of resistance to this class of drugs. Our aim was to estimate the incidence of, and risk factors for, invasive pneumococcal disease caused by fluoroquinolone-resistant Streptococcus pneumoniae in children in South Africa. Methods: 21 521 cases of invasive pneumococcal disease were identified by active national surveillance between 2000 and 2006, with enhanced surveillance at 15 sentinel hospitals in seven provinces introduced in 2003. We screened 19 404 isolates (90% of cases) for ofloxacin resistance and measured levofloxacin minimum inhibitory concentrations (MICs) for all isolates that were ofloxacin resistant. Non-susceptibility to levofloxacin was defined as an MIC of 4 mg/L or more. Nasopharyngeal pneumococcal carriage was assessed in 65 children in two tuberculosis hospitals where invasive pneumococcal disease caused by levofloxacin-non-susceptible S pneumoniae had been detected. Findings: 12 cases of invasive pneumococcal disease were identified as being non-susceptible to levofloxacin, all in children aged under 15 years. All isolates were rifampicin resistant. Outcome was known for 11 of these patients; five (45%) died. Invasive disease caused by levofloxacin-non-susceptible S pneumoniae was associated with a history of tuberculosis treatment (eight [89%] of nine children with non-susceptible isolates had a history of treatment vs 396 [18%] of 2202 children with susceptible isolates; relative risk [RR] 35·78, 95% CI 4·49-285·30) and nosocomial invasive pneumococcal disease (eight [80%] of ten children with non-susceptible isolates had acquired infection nosocomially vs 109 [4%] of 2709 with susceptible isolates; RR 88·96, 19·10-414·29). 31 (89%) of 35 pneumococcal carriers had bacteria that were non-susceptible to levofloxacin. Interpretation: Our data suggest that the use of fluoroquinolones to treat multidrug-resistant tuberculosis in children has led to the emergence of invasive pneumococcal disease caused by levofloxacin-non-susceptible S pneumoniae and its nosocomial spread. Funding: National Institute for Communicable Diseases of the National Health Laboratory Service (South Africa), US Agency for International Development Antimicrobial Resistance Initiative, US Centers for Disease Control and Prevention. © 2008 Elsevier Ltd. All rights reserved.Articl