Endocarditis caused by Abiotrophia defectiva

A 35-year-old man with pre-existing rheumatic heart disease and aortic regurgitation [AR] presented with intermittent fever, ankle swelling and clinical evidence of endocarditis. Transoesophageal echocardiogram [TEE] revealed vegetations and destruction of the aortic valve [AV]. Blood cultures grew a gram positive coccobacillus which was phenotypically identified as Abiotrophia defectvia [A.defectiva]. A diagnosis of infective endocarditis [IE] due to A.defectiva was made. Treatment, with penicillin and gentamicin, was administered for 4 weeks. Mechanical valve replacement was required few days after starting the antibiotic therapy. The patient had a favorable outcome on follow up. Although A.defectiva is an uncommon cause of endocarditis, early and correct identification of this pathogen is important to improve the outcome and the prognosis of patients with IE due to this organism

Extended-spectrum beta-lactamases [ESBLs]: a global problem

Extended-spectrum beta-lactamases [ESBL[s]] constitute a growing class of plasmid-mediated beta-lactamases which confer resistance to broad spectrum beta-lactam antibiotics. They are commonly expressed by Enterobacteriaceae but the species of organisms producing these enzymes are increasing and this is a cause for great concern. The prevalence of ESBL - producing organisms is increasing worldwide and several outbreaks have been reported. Serious infections with these organisms are associated with high mortality rates as therapeutic options are limited. The emergence of ESBLs creates a real challenge for both clinical microbiology laboratories and clinicians because of their dynamic evolution and epidemiology, wide substrate specificity with its therapeutic implications, their significant diagnostic challenges and their prevention and infection control issues. The aim of this review is to increase awareness about this serious antibiotic resistance threat

Distribution of c and ida species among bloodstream isolates

To identify the distribution of C and ida species causing bloodstream infections. This study was conducted at the Armed Forces Hospital, Riyadh, Kingdom of Saudi Arabia. All cases of c and idemia from the period 1996 through to 2002 were retrospectively identified through the records from the Department of Clinical Microbiology. Two hundred and ninety-four c and idemic episodes were identified, 176 [59.9%] occurred in the intensive care units [ICUs], 32 [10.9%] medical, 30 [10.2%] surgical wards, 24 [8%] from patients with hematologic malignancies and 15 [5%] from pediatric wards. C and ida albicans [C. albicans] was the most frequently isolated species with 149 [50.7%] cases, followed by C and ida tropicalis [C. tropicalis] 61 [20.7%], C and ida parapsilosis 32 [10.9%], C and ida krusei [C. krusei] 23 [7.8%] and C and ida glabrata 21 [7.1%]. Other species were not common. There is an increase in the proportion of non C. albicans species as the causative agents of c and idemia. In certain clinical settings, non C. albicans species predominate as in the Adult General Intensive Care Unit with C. tropicalis as the most common. While in patients with hematologic malignancies, C. krusei species is the most common. These findings reinforce the need for continued and active surveillance programs to address the changes in the species distribution among c and idal bloodstream isolates which will help to develop effective, preventive and therapeutic strategies

Antimicrobial susceptiblity pattern of clinical isolates of pseudomonas aeruginosa

To determine the level of resistance to the widely used antipseudomonal antibiotics in clinical isolates of Pseudomonas aeruginosa [P. aeruginosa]. The microbiology database of all clinical isolates of P. aeruginosa at the Armed Forces Hospital, Riyadh, Kingdom of Saudi Arabia, from January 1999 to December 1999 was reviewed. The antimicrobial susceptibilities were determined by a standardized method. Seven hundred and four P. aeruginosa isolates were tested. These strains were commonly isolated from surgical patients followed by intensive care units. Respiratory tract was the most common source of isolation. The antibiotic susceptibility rates were as follows: ciprofloxacin 92.2%, meropenem 91.6%, imipenem 90.2%, amikacin 85.8%, ceftazidime 81.8% piperacillin/tazobactam 81.3% and gentamicin 77.7%. Among 704 strains 6.4% were designated as being multidrug resistant. These were commonly isolated from respiratory tract specimens of patients in intensive care units. The clinical significance of these findings is important in the selection of appropriate empiric treatment of serious P. aeruginosa infections. It emphasizes the importance of a conservative approach to antibiotic therapy and continued antimicrobial susceptibility testing surveillance programs to curtail the problem of antibiotic resistance