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.

Urinary tract infections in renal transplant recipients.

Urinary tract infection (UTI) is the most common infectious complication following renal transplantation. The purposes of this study were to determine the causative agents of UTIs among renal transplant recipients and to compare the antibiotic susceptibilities of Escherichia coli strains isolated from renal transplant recipients and complicated community-acquired UTIs. We evaluated 75 episodes of 63 recipients with confirmed UTI who underwent transplantation during the period 1981 to 2006 at our center. Medical records of the patients were reviewed retrospectively. To compare the susceptibility rates of E coli, 226 isolates from nontransplant patients with complicated community-acquired UTIs were also evaluated. Ten episodes (13.3%) occurred in the first month following the transplantation, 11 (14.7%) in the period of the second month to the sixth month, and 54 (72%) after the sixth month of transplantation. Forty-six (61.3%) isolates were E coli. Among these isolates, ciprofloxacin resistance rates were 50% (2/4) in the first month after transplantation, 75% (6/8) in the period of the second month to the sixth month, and 32.4% (11/34) beyond 6 months after transplantation. The resistance rates of trimethoprim/sulfamethoxazole (TMP-SMX) in the same time periods were 100% (4/4), 87.5% (7/8), and 70.6% (24/34), respectively. The rates of resistance to TMP-SMX among E coli isolated from renal recipients were significantly higher than those in community-acquired complicated UTIs. The increased resistance of urinary pathogens to this agent is a major concern. Although high resistance rates of ciprofloxacin against E coli strains were determined in this group, it was not found to be statistically significant.

Etiologic agents of diarrhea in solid organ recipients.

After transplantation, diarrhea may be caused by infectious agents, drug-specific effects, metabolic conditions, or mechanical complications of surgery. Determining the cause helps to determine whether to initiate antimicrobial therapy and the duration of treatment. In this study we aimed to determine the causes of diarrhea in kidney or liver recipients. Fifty-two diarrhea episodes among 43 solid organ recipients were evaluated. The cause of diarrhea was detected in 43 patients (82.6%). Infectious etiologies accounted for 33 out of the 43 episodes (76.7%) in which a specific cause was determined: Giardia lamblia in 9, Cryptosporidium parvum in 7, cytomegalovirus (CMV) in 6, Clostridium difficile in 3, Campylobacter jejuni in 2, Shigella sonnei in 2, Salmonella enteritidis in 1, rotavirus in 1, Entamoeba histolytica in 1, and Blastocystis hominis in 1. Non-infectious etiologies were found for 10 episodes (23.3%): mycophenolate mofetil-associated diarrhea in 5, antibiotic-associated diarrhea in 2, colchicine-associated diarrhea in 2, and laxative drug-associated in 1. Non-infectious etiologies seem to be relatively common causes of diarrhea among transplant recipients. Therapy was adjusted in 5 patients because of mycophenolate mofetil-associated diarrhea. CMV and C. parvum, which are seldom seen in the normal population, were frequent causes of diarrhea in this group. Evaluating the transplant recipients for non-infectious causes of diarrhea is important in prompt diagnosis and treatment.

Opportunistic posterior uveal infections in renal transplant patients.

AIMS: To describe the cases of opportunistic posterior uveal infection diagnosed in renal transplant recipients at a single center over a 10-year period. METHODS: The study involved 1156 patients who underwent renal transplantation. Five of the recipients were diagnosed with posterior uveal infection. The specific diagnoses were acute retinal necrosis (two cases), cytomegalovirus retinitis (one case), nocardial chorioretinitis (one case), or tuberculoid granuloma (one case). RESULTS: The five patients were aged 27 to 55 years, and the interval from renal transplantation to uveal infection ranged from 7 months to 16 years. All patients were receiving immunosuppressive treatment at the time of the posterior uveal infection. Acute retinal necrosis was diagnosed in cases I and II at 2 and 3 years after transplantation, respectively. In both cases, fundus examination revealed moderate vitritis and yellow-white lesions representing confluent retinitis. In case III (cytomegalovirus retinitis), 7 months after transplantation the patient developed extensive hemorrhage and confluent white exudates, periphlebitis, and perivascular sheathing in the right eye. In case IV, culture of a fine-needle aspirate from a well-demarcated, white-yellow, elevated choroidal lesion in the superotemporal region of the macula revealed nocardial infection. Fundus examination of the right eye of case V revealed a small, hypopigmented choroidal lesion superior to the optic disc. The lesion was identified as a choroidal tuberculoid granuloma. CONCLUSIONS: Opportunistic chorioretinal infections can occur at any time after renal transplantation. So it is important that every kidney recipient undergo regular ophthalmic examinations throughout his or her lifetime.

Value of automatized blood culture systems in the diagnosis of continuous ambulatory peritoneal dialysis peritonitis.

Peritonitis is a common clinical problem that occurs in patients with end-stage renal disease treated by peritoneal dialysis. The aim of this study was to evaluate the value of blood culture systems for the diagnosis of continuous ambulatory peritoneal dialysis (CAPD) peritonitis among 26 samples of peritoneal fluid obtained from patients with the suspicion of CAPD peritonitis. Significant growth was detected in 12 (70.5%) of 17 bacteria-positive samples. The most striking finding was that 8 (66.6%) of these 12 results were obtained only from blood culture bottles. The identified pathogens were methicillin-sensitive coagulase-negative staphylococci (n = 5), alpha-hemolytic streptococci (n = 2), Corynebacterium spp. (n = 2), Escherichia coli (n = 2), and Enterococcus faecalis (n = 1). Using blood culture bottles inoculated with peritoneal fluid at the bedside, rather than submitting the specimen to the laboratory for later processing, is advocated in the prompt diagnosis of CAPD peritonitis.

Incidence of inducible clindamycin resistance in staphylococci: first results from Turkey.

In total, 408 staphylococcal isolates were tested for inducible clindamycin resistance (ICR) by the disk-diffusion induction test (D-test). ICR was detected in 5.7% of 105 methicillin-resistant Staphylococcus aureus (MRSA) isolates, 3.6% of 111 methicillin-susceptible S. aureus isolates, 30.8% of 94 methicillin-resistant coagulase-negative staphylococcal (CoNS) isolates, and 11.2% of 98 methicillin-sensitive CoNS isolates. All MRSA isolates that were erythromycin-resistant and clindamycin-susceptible were positive by the D-test. The same results were obtained with an azithromycin instead of an erythromycin disk. All isolates were susceptible to quinupristin-dalfopristin. The cost-benefit of the d-test should be evaluated locally after determining the incidence of the different resistance phenotypes.