Risk factors for extended-spectrum beta-lactamase positivity in uropathogenic Escherichia coli isolated from community-acquired urinary tract infections.

The aim of this prospective cohort study was to determine the risk factors for community-acquired urinary tract infections (UTIs) caused by extended-spectrum beta-lactamase (ESBL)-positive Escherichia coli and the distribution of the ESBL enzyme types. Structured forms were filled in for patients diagnosed with community-acquired UTI in four different geographical locations in Turkey. The forms and the isolates were sent to the central laboratory at Baskent University Hospital, Ankara. Antimicrobial susceptibility was determined according to the CLSI criteria. PCR and DNA sequencing were used to characterize the bla(TEM), bla(CTX-M) and bla(SHV) genes. Multivariate analysis was performed using logistic regression. A total of 510 patients with UTI caused by Gram-negative bacteria were included in this study. ESBLs were detected in 17 of 269 (6.3%) uropathogenic E. coli isolates from uncomplicated UTIs and 34 of 195 (17.4%) E. coli isolates from complicated UTIs (p <0.001). According to multivariate analysis, more than three urinary tract infection episodes in the preceding year (OR 3.8, 95% CI 1.8-8.1, p <0.001), use of a beta-lactam antibiotic in the preceding 3 months (OR 4.6, 95% CI 2.0-0.7, p <0.001) and prostatic disease (OR 9.6, 95% CI 2.1-44.8, p 0.004) were found to be associated with ESBL positivity. The percentages of isolates with simultaneous resistance to trimethoprim-sulphamethoxazole, ciprofloxacin and gentamicin were found to be 4.6% in the ESBL-negative group and 39.2% in the ESBL-positive group (p <0.001). Forty-six of 51 ESBL-positive isolates (90.2%) were found to harbour CTX-M-15. Therapeutic alternatives for UTI, particularly in outpatients, are limited. Further clinical studies are needed to guide the clinicians in the management of community-acquired UTIs.

Clinical experience with three combination regimens for the treatment of high-risk febrile neutropenia.

INTRODUCTION: The objective of this study was to compare the safety and efficacy of ceftazidime (2 g every 8 h), piperacillin/tazobactam (4 g/500 mg every 6 h), and meropenem (1 g every 8 h), when combined with amikacin (15 mg/kg once daily), in the empirical treatment of high-risk febrile neutropenic episodes in patients with haematological malignancy. MATERIALS AND METHODS: A prospective, comparative study designed in the haematology unit of a university hospital in Turkey. RESULTS: A total of 89 febrile episodes in 60 neutropenic patients were treated; 29 febrile episodes in 23 patients with ceftazidime plus amikacin (group 1), 30 episodes in 25 patients with piperacillin/tazobactam plus amikacin (group 2), and 30 episodes in 25 patients with meropenem plus amikacin (group 3). The 3 groups were comparable in terms of age, sex, underlying malignancy, pretherapy neutrophil counts, duration of neutropenia and types of infections. Neutropenia, since the start of fever, persisted for > or =10 days in all of the episodes in the 3 study groups. Nearly all of the episodes were seen in patients with acute leukaemia. In 25.8% (23/89) of the febrile neutropenia episodes, an aetiologic organism was isolated, with gram-negative bacteria being the most commonly isolated. The success without modification rates were 34.5%, 30% and 36.7% for groups 1, 2 and 3, respectively (P >0.05). After modification with a different class of antimicrobial therapy, the response rates increased to 65.5%, 63.3% and 70% for groups 1, 2 and 3, respectively (P >0.05). The mean duration of treatment and the time to defervescence were also comparable in all groups. In all arms, side effects were minimal. CONCLUSIONS: It is concluded that the 3 regimens were equally effective and safe in the empirical treatment of high-risk febrile neutropenic episodes.

Isolated thrombocytopenia: the presenting finding of typhoid fever.

Thrombocytopenia is generally seen as a complication in typhoid fever. However, it can also be encountered as a presenting sign on admission. A 29-year-old man with complaints of fever and diarrhoea was hospitalized because of isolated thrombocytopenia encountered on routine complete blood count examination. The diagnosis of typhoid fever was established when Salmonella typhi was isolated from the blood cultures. The platelet count returned to normal level within the first week of ceftriaxone therapy. Possible mechanisms of thrombocytopenia were discussed.