Diagnosis of endocarditis caused by Mycobacterium abscessus

We report a fatal case of native valve endocarditis due to Mycobacterium abscessus in a hemodialysis patient. The diagnosis was based on culture isolation of acid-fast bacilli from peripheral blood and a permanent catheter tip, and their identification as M abscessus by a reverse hybridization-based assay and direct DNA sequencing of the 16S-23S internal transcribed spacer region. Rapid diagnosis and combination therapy are essential to minimize mortality due to this pathogen. Although combination therapy was started with clarithromycin and tigecycline, the patient refused to take clarithromycin due to severe abdominal pain. The patient became afebrile after therapy with tigecycline alone although bacteremia persisted. He was discharged against medical advice and readmitted three months later for persistent fever. His blood cultures again yielded M abscessus and a transesophageal echocardiogram showed two mobile vegetations. The patient was noncompliant with therapy and died due to cardiac arrest and multiorgan failure. This report shows that M abscessus should also be considered in the differential diagnosis of infective endocarditis in hemodialysis patients

Antimicrobial resistance in clinical isolates of Streptococcus pneumoniae in a tertiary hospital in Kuwait, 1997-2007: Implications for empiric therapy

This study evaluated antibiotic resistance trends in Streptococcus pneumoniae isolated in a tertiary hospital in Kuwait and its implications for empiric therapy. Antimicrobial susceptibility of 1353 strains of S. pneumoniae isolated from clinical specimens during 1997-2007 was performed by disc diffusion method. MIC was determined by E test. The results were compared for 1997-2001, 2002-2005 and 2006-2007. The prevalence of resistance for the respective periods were as follows: penicillin, 51.3%, 61.3% and 54.5%; erythromycin, 31.2%, 36.7% and 37.7%; tetracycline, 30.8%, 45.3% and 41.3%; co-trimoxazole, 49.5%, 58.5% and 62.8%; clindamycin, 20.4%, 20.6% and 24.5% and chloramphenicol, 8.1%, 8.9% and 3.7%. All were susceptible to vancomycin and rifampicin. For oxacillin-resistant isolates, penicillin resistance was rare [0.8%] with the new non-meningeal breakpoint. However, using the meningeal breakpoints, resistance increased for penicillin from 0.6%, to 28.7%, for cefotaxime from none to 16.5%, and for ceftriaxone from none to 7%. Intermediate resistance to meropenem increased from 1.7% to 22.4%. Multiple drug resistance increased from 22.4% to 37.8%. The study demonstrated that antimicrobial resistance of S. pneumoniae is increasing in Kuwait. However, the results of MIC determinations indicated that penicillin can still be used for therapy of non-meningeal infections. High prevalence of erythromycin resistance suggests that therapy of pneumonia with a macrolide alone may result in failure and should be based on results of susceptibility testing

Rising incidence of beta-lactam resistance among pneumococci in Kuwait: Failure of cefotaxime therapy in pneumococcal meningitis

Pneumococcal resistance to antimicrobial agents has become a global problem. This study was done to evaluate the resistance of Streptococcus pneumoniae [pneumococci] to penicillin G in Kuwait, and to assess the efficacy of other -lactam agents [cefotaxime or ceftriaxone] in the management of invasive pneumococcal infections. Surveillance studies were done in a general teaching hospital in Kuwait for penicillin G resistance [intermediate or high level resistance] of pneumococci isolated from clinical specimens by agar diffusion method using oxacillin [1 micro g] disc. In cases of pneumococcal meningitis, minimum inhibitory concentrations [MICs] of penicillin and cefotaxime were determined by agar dilution method, to differentiate intermediate resistance and high level resistance. An increase in the incidence of penicillin G-resistant pneumococci from 20.6% [94 out of 457 isolates] for the period 1985-1988 to 28.5% [40 out of 140 isolates] during 1992-1994 and 38.3% [43 out of 112 isolates] during 1995/96 was observed. During the period 1992-1994, 40-45% [7 out of 16 isolates] blood culture isolates of pneumococci were intermediate or highly resistant to penicillin. Therapy with cefotaxime or ceftriaxone produced a positive outcome in 6 of the 7 patients. However, failure of cefotaxime therapy to achieve a cure was noted in 1 patient who had systemic lupus erythematosus and intermediate resistant [penicillin MIC 0.5 mg/l; cefotaxime MIC 1 mg/l] pneumococcal septicaemia complicated with meningitis. A cure was however achieved with the addition of chloramphenicol to the regimen. Resistance of pneumococci to penicillin G and other -lactam agents is increasing in Kuwait. Penicillin-resistant pneumococcal bacteraemia in an immunosuppressed setting, if managed with cefotaxime or ceftriaxone, should be given high doses [cefotaxime 12 g/day or ceftriaxone 4 g/day] from the beginning. Cases of pneumococcal meningitis with cefotaxime-intermediate resistant strains [MIC 0.5-1 mg/l] on monotherapy consisting of cefotaxime or ceftriaxone should be viewed with caution. Chloramphenicol or vancomycin with rifampicin should be added to the regimen if therapeutic failure is suspected

Pneumococci relatively resistant to penicillin

Review of cases with meningitis in a general hospital in Kuwait showed high prevalence of relatively resistant Streptococcus pneumoniae [RRSP]. During an observation period of 3 years, 6 cases of pneumococcal meningitis were encountered; 4 cases were caused by RRSP. The use of screening tests with 1 micro g oxacillin in disc diffusion susceptibility tests helped to identify less susceptible strains which were then confirmed by determining their minimum inhibitory concentration. Appropriate antibiotic choices led to successful therapy in all instances. The importance of detecting RRSP in cases of meningitis is emphasized