[Comparative evaluation of e-test and disk diffusion methods for susceptibility testing of Nocardia species]. / Nocardia Klinik Izolatlarinin Antibiyotik Duyarliliklarinin Belirlenmesinde E-Test ve Disk Difüzyon Yöntemlerinin Karsilastirilmasi

Variations in antimicrobial susceptibility among different Nocardia species limit the options for therapy. It is very difficult to perform antimicrobial susceptibility testing of these bacteria due to their slow growth rate and problems in inoculum preparation. The aim of this study was to compare E-test and disk diffusion methods for the determination of antimicrobial susceptibilities of Nocardia isolates. Since E-test is considered as 90% consistent with the gold standard microdilution method recommended by Clinical and Laboratory Standards Institute (CLSI), it was chosen for comparison with disk diffusion and in order to determine the use of disk diffusion in routine practice. A total of 21 Nocardia strains isolated from clinical specimens (12 lung, 7 brain and 2 skin/soft tissue samples) were included in the study. Six of the isolates were identified as N.asteroides, six were N.farcinica, five were N.cyriacigeorgica and four were Nocardia spp. By conventional methods. Susceptibilities of strains to ampicillin, ampicillin-sulbactam, amoxicillin-clavulanic acid, ceftazidime, sefepime, imipenem, gentamicin, erythromycin, levofloxacin, moxifloxacin, trimethoprim- sulfamethoxazole, piperacillin-tazobactam, tigecycline, and linezolid were investigated by using E-test and/or disk diffusion methods. The results were interpreted according to the CLSI breakpoints for Staphylococcus spp. All of the strains were found to be resistant to ceftazidime, piperacillin-tazobactam and ampicillin, however susceptible to levofloxacin, moxifloxacin, trimethoprim-sulfamethoxazole tigecycline, and linezolid. The concordance between the methods in terms of susceptibility testing were 100% for ampicillin, ceftazidime, imipenem, gentamicin and linezolid; 85.7% for erythromycin, 76.2% for sefepime, 73.7% for moxifloxacin, 71.4% for piperacillin-tazobactam, 70% for ampicillin-sulbactam and 46.2% for amoxicillin- clavulanic acid. In conclusion, the therapy must be planned according to the results of antimicrobial susceptibility testing. Disk diffusion is not a reliable method due to the high rates of very major errors. E-test would be an alternative method being practical and easily evaluated, especially in routine laboratories in which the reference method could not be performed.

[Comparative evaluation of in vitro activities of carbapenems against gram-negative pathogens: Turkish data of COMPACT study]. / Karbapenemlerin Gram-Negatif Patojenlere Karsi In Vitro Aktivitelerinin Karsilastirmali Degerlendirmesi: COMPACT Çalismasi Türkiye Verisi.

The aim of this study was to determine the in vitro activities of doripenem, imipenem, and meropenem against clinical gram-negative isolates. A total of 596 clinical isolates were obtained from intensive care unit (ICU) and non-ICU patients in 10 centers over Turkey between September-December 2008. The origin of the isolates was patients with nosocomial pneumonia (42.4%), bloodstream infections (%40.4), and complicated intraabdominal infections (17.1%). Of the isolates, 51.8% were obtained from ICU patients. The study isolates consisted of Pseudomonas spp. in 49.8%, Enterobacteriaceae in 40.3%, and other gram-negative agents in 9.9%. The minimum inhibitory concentrations (MIC) for doripenem, imipenem and meropenem were determined for all isolates in each center using Etest® strips (AB Biodisk, Solna, Sweden). Of the isolates, 188 (31.5%) were resistant to at least one of the carbapenems. MIC50 of doripenem against Pseudomonas spp. Was 1 mg/L which was similar to that of meropenem and two-fold lower than imipenem. Susceptibility to carbapenems in P.aeruginosa was 64% for doripenem at an MIC level of 2 mg/L, 53.9% and 63% for imipenem and meropenem at an MIC level of 4 mg/L, respectively. Doripenem and meropenem showed similar activity with the MIC90 of 0.12 mg/L whereas imipenem was four-fold less active at 0.5 mg/L. Against other gramnegative pathogens, mostly Acinetobacter spp., MIC50 was 8 mg/L for doripenem and 32 mg/L for other two carbapenems. P.aeruginosa isolates were inhibited 84.2% with doripenem and 72.1% with meropenem at the MIC level of 8 mg/L. Doripenem generally showed similar or slightly better activity than meropenem and better activity than imipenem against pathogens collected in this study. Against Pseudomonas spp., doripenem was the most active of the three carbapenems. Doripenem and meropenem were equally active against Enterobacteriaceae and at least four-fold more active than imipenem. It was concluded that doripenem seemed to be a promising agent in the treatment of nosocomial pneumonia, blood stream infections and intraabdominal infections particularly in patients who were under risk of developing antimicrobial resistance.

Neurobrucellosis: an evaluation of a rare presentation of brucellosis from a tertiary care centre in Central Anatolia, Turkey.

Nervous system involvement is a rare manifestation of brucellosis. We describe our experience of the diagnosis, treatment and final outcome of patients with neurobrucellosis at the Erciyes University Gevher Nesibe Hospital, a tertiary referral centre in Central Anatolia, Turkey. Thirty-six adult patients were diagnosed with neurobrucellosis from January 1997 to December 2006. Headache and fever were the most common symptoms. Neck stiffness was present in 25 patients. Brucella spp was isolated from the blood of nine patients and from the cerebrospinal fluid of 11. Doxycycline (by mouth) plus rifampin (by mouth) with ceftriaxone (intravenously) were the most common treatment choices. Three patients died as a result of problems other than neurobrucellosis and relapse occurred in one patient. Neurobrucellosis presents with hetoregenous clinical signs.

Sepsis and meningitis due to Listeria monocytogenes.

PURPOSE: This study focused on the effect of immuno-compromising conditions on the clinical presentation of severe listerial infection. PATIENTS AND METHODS: Nine human listeriosis cases seen from 1991-2002 were reviewed. All adult patients, from whose blood, peritoneal fluid or cerebrospinal fluid (CSF) the L. monocytogenes was isolated, were included in this retrospective study. RESULTS: Listeriosis presented as primary sepsis with positive blood cultures in 5 cases and meningitis with positive CSF cultures in 4 cases. All of these patients had at least one underlying disease, most commonly, hematologic malignancy, diabetes mellitus, amyloidosis and hepatic cirrhosis; 55.6% had received immunosuppressive or corticosteroid therapy within a week before the onset of listeriosis. The patients were adults with a mean age of 60 years. Fever, night sweats, chills and lethargy were the most common symptoms; high temperature (> 38 degrees C), tachycardia, meningeal signs and poor conditions in general were the most common findings on admission. The mortality rate was 33.3% and was strictly associated with the severity of the underlying disease. Mortality differences were significant between sepsis (20%) and meningitis (50%) patients. CONCLUSION: Listeriosis as an uncommon infection in our region and that immuno- suppressive therapy is an important pre-disposing factor of listeriosis. Sepsis and meningitis were more common in this group of patients and had the highest case-fatality rate for food-borne illnesses.

Doxycycline plus streptomycin versus ciprofloxacin plus rifampicin in spinal brucellosis [ISRCTN31053647].

BACKGROUND: The optimal treatment regimen and duration of the therapy is still controversial in spinal brucellosis. The aim of this study is to compare the efficacy, adverse drug reactions, complications and cost of ciprofloxacin plus rifampicin versus doxycycline plus streptomycin in the treatment of spinal brucellosis. METHODS: The patients diagnosed as spinal brucellosis between January 2002 to December 2004 were enrolled into the study. Patients were enrolled into the two antimicrobial therapy groups (doxycycline plus streptomycin vs. ciprofloxacin plus rifampicin) consecutively. For the cost analysis of the two regimens, only the cost of antibiotic therapy was analysed for each patient. RESULTS: During the study period, 31 patients with spinal brucellosis were enrolled into the two antimicrobial therapy groups. Fifteen patients were included in doxycycline plus streptomycin group and 16 patients were included in ciprofloxacin plus rifampicin group. Forty-two levels of spinal column were involved in 31 patients. The most common affected site was lumbar spine (n = 32, 76%) and involvement level was not different in two groups. Despite the disadvantages (older age, more prevalent operation and abscess formation before the therapy) of the patients in the ciprofloxacin plus rifampicin group, the duration of the therapy (median 12 weeks in both groups) and clinical response were not different from the doxycycline plus streptomycin. The cost of ciprofloxacin plus rifampicin therapy was 1.2 fold higher than the cost of doxycycline plus streptomycin therapy. CONCLUSION: Classical regimen (doxycycline plus streptomycin), with the appropriate duration (at least 12 weeks), is still the first line antibiotics and alternative therapies should be considered when adverse drug reactions were observed.

Epidemiological and molecular characteristics of meticillin-resistant Staphylococcus aureus in Turkey: A multicentre study.

The aim of this study was to investigate the epidemiological and molecular features of clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates in Turkey. MRSA isolates were collected from six regions of Turkey. The mecA and nuc genes were detected by PCR. Antimicrobial susceptibilities were determined by the disk diffusion method. Staphylococcal cassette chromosome mec (SCCmec) and staphylococcal protein A (spa) typing were performed by the sequencing method for 270 randomly selected MRSA isolates. The US Centers for Disease Control and Prevention (CDC) definition was used for epidemiological diagnosis of community-associated MRSA (CA-MRSA). Resistance rates of MRSA to ciprofloxacin, gentamicin, clindamycin, erythromycin, rifampicin, trimethoprim/sulfamethoxazole and tetracycline were 93.4%, 81.2%, 38.5%, 57.8%, 93.9%, 1.1% and 93.1%, respectively. The most frequent SCCmec type was SCCmec III (91.1%). SCCmec type IV was found in 5.2% of the isolates. The most frequent spa type was t030 (81.1%). Five isolates were CA-MRSA if only the epidemiological definition was used (5/725; 0.7%). Two isolates were defined as CA-MRSA both by epidemiological features and SCCmec typing (2/270; 0.7%). Of 14 SCCmec type IV isolates, 12 were not defined as CA-MRSA by epidemiological features. In conclusion, this is the most comprehensive multicentre study in Turkey investigating MRSA using both epidemiological and genotypic features. The CA-MRSA rate is low in Turkey. Combined use of epidemiological and genotypic methods is the most accurate approach for the diagnosis of CA-MRSA.

[Salmonella enteritidis: an unusual meningitis agent in an adult patient]. / Salmonella enteritidis: eriskin hastada nadir bir menenjit etkeni.

Salmonella species may cause wide spectrum of infections changing from enterocolitis to sepsis. However, Salmonella meningitis in adults is a rare but important clinical condition with a high mortality rate. In this report, a 71 years old male patient with Salmonella enteritidis meningitis who was followed-up with the diagnosis of immune thrombocytopenic purpura and had been administered azothioprin and prednisolone, has been presented and similar cases in the literature have been reviewed. The cerebrospinal fluid culture yielded S. enteritidis, and the isolate was intermediate susceptible to ampicillin, susceptible to cefotaxime, trimethoprim-sulphametoxasole, ciprofloxacin and chloramphenicol. Our patient was successfully treated with ceftriaxone (2 x 2 gr i.v.) and discharged with total cure.

Microbiologically documented infections following peripheral blood stem cell transplantation: single center experience.

This study was performed to assess the incidence of infectious complications in patients undergoing autologous and allogeneic hematopoietic stem cell transplantation (HSCT). The characteristics of microbiologically documented infections in 114 consecutive patients undergoing HSCT (84 autologous, 30 allogeneic) were analyzed. Conditioning and the pre-engraftment period until one month was defined as the early period; the post-engraftment period until one year was defined as the late period. All patients received antibiotic prophylaxis and hematopoietic growth factors during neutropenia. Febrile patients received imipenem-cilastatin or cefepime plus amikacin or ceftazidime plus amikacin. A total of 117 episodes with microbiologically documented infections were seen 90 of 114 patients and 79% of the patients experienced at least one febrile episode during their post-transplant course. Of these episodes, 69 (59%) were in the early period and 48 (41%) were in the late period. In the early period, 38.8% of causative organisms were gram-positive, 51.5% were gramnegative and 7.7% were fungi. The most common pathogens were coagulase-negative Staphylococcus (CoNS) and E. coli in the early period. In the late period, 44.6% of causative organisms were gram-positive, 44.6% were gram-negative and 6.8% were fungi. CoNS and E. coli were also the most commonly isolated agents in this period. Resistance to methicillin was detected in 47.4% of S. aureus and 86.5% of CoNS isolates. The isolation rate was in accordance with previous reports; similar percentages of gram-positive and gram-negative isolates were found in patients undergoing HSCT in both periods. However, a remarkably low rate of viridans streptococci and fungi were observed. The spectrum of pathogens detected in these cases serves as the basis for recommendations on the choice of empiric antimicrobial treatment regimens. Therefore, studies reporting local microbiological findings are necessary. We suggest that local microbiologic surveillance should be known before empiric antimicrobial therapy is started in each institution.

Antimicrobial susceptibilities of 40 isolates of Bacillus anthracis isolated in Turkey.

Forty clinical isolates of Bacillus anthracis were studied. The MIC(90) values of penicillin G, doxycycline, ciprofloxacin, gatifloxacin, and levofloxacin were 0.016, 0.03, 0.06, 0.06 and 0.12 mg/l, respectively. Susceptibilities suggest that the quinolones may also be considered as an alternative therapy for anthrax.

Prevalence of antimicrobial resistance in Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis and Streptococcus pyogenes: results of a multicentre study in Turkey.

The in vitro activities of several antimicrobial agents against clinical isolates of Streptococcus pneumoniae (283), Haemophilus influenzae (272), Moraxella catarrhalis (179) and Streptococcus pyogenes (256) were determined in a multicentre study with the participation of five hospitals from four cities in Turkey. Penicillin resistance in S. pneumoniae was evaluated using the E-test and the remaining agents by disk diffusion. For S. pneumoniae overall 25.8% of the isolates were intermediately and 3.9% were highly resistant to penicillin and resistance to chloramphenicol, azithromycin and trimethoprim/sulphamethoxazole (TMP/SMX) was 3.8, 2.1 and 55.4%, respectively. Seven percent of H. influenzae produced beta-lactamase and all were susceptible to cefotaxime and azithromycin; the highest rate of resistance, 23.5%, was for TMP/SMX. Eighty-one percent of M. catarrhalis isolates produced beta-lactamase, 18.4% were resistant to TMP/SMX and all were susceptible to sulbactam/ampicillin combination. Resistance to chloramphenicol and azithromycin of S. pyogenes was 2.2 and 1.9%, respectively.

Catheter-related bacteremia due to Kocuria rosea in a patient undergoing peripheral blood stem cell transplantation.

BACKGROUND: Micrococcus species may cause intracranial abscesses, meningitis, pneumonia, and septic arthritis in immunosuppressed or immunocompetent hosts. In addition, strains identified as Micrococcus spp. have been reported recently in infections associated with indwelling intravenous lines, continuous ambulatory peritoneal dialysis fluids, ventricular shunts and prosthetic valves. CASE PRESENTATION: We report on the first case of a catheter-related bacteremia caused by Kocuria rosea, a gram-positive microorganism belonging to the family Micrococcaceae, in a 39-year-old man undergoing peripheral blood stem cell transplantation due to relapsed Hodgkin disease. This uncommon pathogen may cause opportunistic infections in immunocompromised patients. CONCLUSIONS: This report presents a case of Kocuria rosea catheter related bacteremia after stem cell transplantation successfully treated with vancomycin and by catheter removal.

Community-acquired pneumonia and empyema caused by Pseudomonas stutzeri: a case report.

Pseudomonas stutzeri is an aerobic, nonfermentative, gram-negative rod with polar monotrichous flagella. We report the case of a four-year-old boy who developed community-acquired pneumonia and empyema caused by P. stutzeri. To our knowledge, this is the first report on community-acquired pneumonia and empyema caused by this organism in childhood.

[Salmonella enterica serotypes and Salmonella infections: a multicenter study covering ten provinces in Turkey]. / Salmonella enterica serotipleri ve Salmonella enfeksiyonlari: Türkiye'de on ili kapsayan çok merkezli bir çalisma.

In order to find the distinctive features of Salmonellae and Salmonella infections in Turkey, 620 Salmonellae strains, isolated from various clinical samples (481 stool, 108 blood, 12 urine, 3 bone marrow, 3 cerebrospinal fluid, 9 pus, and one from each of the bile, pleural fluid, wound, catheter samples) in 13 clinical microbiology laboratories of 10 provinces in Turkey (Ankara, Antalya, Bursa, Edirne, Eskisehir, Istanbul, Izmir, Kayseri, Konya and Trabzon) between July 1, 2000 and June 30, 2002, were serotyped. Among the patients 43% were female, 57% were male, 63.2% were from outpatient clinics and 36.8% were hospitalized patients. Seventy eight percent of the patients had gastroenteritis, 10.7% had septicemia/local infection, 9.8% had typhoid/paratyphoid fever and 1.5% were carriers. Incidence of gastroenteritis was higher in 0-5 years age group (p<0.001). Of the 620 Salmonella enterica isolates, 47.7% were S. Enteritidis, 34.7% S. Typhimurium, 6% S. Paratyphi B, 2.9% S. Typhi, 0.2% S. paratyphi A, 6.1% serogroup C1, and 2.4% serogroup C2. S. Enteritidis was the most common serotype in all provinces except for Kayseri, where S. Typhimurium was found to be the most common serotype (68.2%). Overall, the most frequently isolated serotype was S. Enteritidis, also being the most common serotype in stool and blood cultures. During the surveillance period two outbreaks have occurred, the first one by S. Enteritidis strains in Edirne, and the second one by S. Typhimurium strains in Kayseri. As a result, Salmonella infections are still a common health problem in Turkey, and active surveillance of Salmonella infections has vital importance.

Clonal diversity and high prevalence of OXA-58 among Acinetobacter baumannii isolates from blood cultures in a tertiary care centre in Turkey.

Genotypic diversity, antimicrobial susceptibilty, and presence of OXA-genes were assessed in 100 nosocomial Acinetobacter strains from a tertiary-care hospital, Turkey. Ninety-eight isolates were identified by AFLP library identification to Acinetobacter baumannii. Furthermore, the isolates were divided into 30 AFLP clusters and single strains at a similarity cut-off level of 90%, the defined strain level. Most of these clusters grouped together in larger clusters at a lower similarity level, indicating diversification beyond the strain level. At a similarity level of 80%, the A. baumannii isolates were allocated to eight clusters of multiple isolates (A, C, D, E, G, H, J, L) and 3 single isolates (B, F, I). Comparison of the isolates to those of the Leiden AFLP database revealed that the large cluster H (41 isolates) corresponded to a tentative novel international clone previously identified both by AFLP and MLST (CC15). Clusters D and E grouped with European (EU) clone II isolates, and cluster J with those EU clone I. Clusters A, C, G, and L could not be identified to any international clone. MLST of selected isolates of the major clusters corroborated the clone allocation by AFLP, except for the tested cluster A isolate which was identified to CC2 (EU clone II). Carbapenem resistance of 75 A. baumannii isolates was associated with the blaOXA-58-like gene or blaOXA-51-like with ISAba1 upstream. Altogether, 99% of the Acinetobacter isolates were multidrug resistant (MDR) and 77% extensively drug resistant (XDR). The findings show that multiple strains and clones MDR and XDR A. baumannii were endemic in the hospital.

Ten-year surveillance of invasive Streptococcus pneumoniae isolates in central Turkey prior to the introduction of a conjugate vaccine.

INTRODUCTION: The aim of this study was to characterize the serotypes and antimicrobial susceptibility patterns of invasive Streptococcus pneumoniae isolates in central Turkey. METHODOLOGY: A total of 332 invasive S. pneumoniae isolates were identified, serotyped and tested for antimicrobial susceptibility by routine microbiological methods. RESULTS: The most common serogroups/serotypes were 1, 19, 3, 18, 6, 14, and 7 in rank order. Serogroup/serotype coverage of the 23-valent polysaccharide vaccine, and the 7-, 10-, and 13-valent conjugate vaccines were 96%, 44%, 78.6%, 96.4%, respectively. Overall, 20 (6%) of the isolates were resistant to penicillin, 1 (0.3%) to cefotaxime, 20 (6%) to erythromycin, 13 (4%) to cloramphenicol, and 120 (36%) to trimethoprim-sulfamethoxasole. Among cerebrospinal fluid (CSF) isolates, 20 (18.5%) were resistant to penicillin (26.3% and 11.5%, respectively, of child and adult meningitis cases; p ≥ 0.05). CONCLUSIONS: Although the seven-valent conjugate vaccine is expected to protect less than half of children younger than three years of age, of the incorporation of this vaccine into the routine immunization program of Turkey is advised to continue. However, the 13-valent conjugate vaccine, including serotypes 1, 3, 5, and 7, has the most potential prevent the highest burden of invasive pneumococcal diseases in this age group.

Factors influencing survival in patients with multi-drug-resistant Acinetobacter bacteraemia.

OBJECTIVES: The incidence of multi-drug-resistant (MDR) Acinetobacter strains is increasing and therapeutic options are limited. However, controversy exists regarding the mortality attributable to antimicrobial resistance. The aim of this study was to analyse the clinical features and outcomes of patients with MDR Acinetobacter calcoaceticus-Acinetobacter baumannii complex (Acb complex) bacteraemia and determine the factors influencing survival by using 14-day mortality as the main outcome measure. METHODS: An observational study was conducted at a tertiary care hospital in Turkey from February 2007 to March 2008. Only one bacteraemic episode from one patient was included in the study. RESULTS: A total of 100 clinically significant Acb complex bacteraemic episodes were detected. The overall mortality was 63% in 14 days. According to univariate analysis, diabetes mellitus, haematological malignancy, unknown source of bacteraemia, septic shock, resistance to carbapenems, and inappropriate empirical therapy were associated with mortality amongst patients with Acb complex bacteraemia. Multivariate analysis showed that diabetes mellitus (RR, 1.68; 95% CI, 1.22-1.76), carbapenem resistance (RR, 1.63; 95% CI, 1.19-1.89), and septic shock (RR, 1.65; 95% CI, 1.23-1.85) were independent risk factors for 14-day mortality. CONCLUSION: Although severe underlying diseases play an important role in the clinical outcome of patients with Acb complex bacteraemia, carbapenem resistance and inappropriate therapy are of great concern. Special attention should be paid to infection control practices in the hospitals where MDR Acinetobacter infections are endemic, and well-controlled prospective clinical trials are needed to determine the optimal antimicrobial therapy in critically ill patients suspected of having MDR Acinetobacter bacteraemia.

Disseminated nocardiosis due to unusual species: two case reports.

Pulmonary nocardiosis is the major clinical manifestation of human nocardiosis and disseminated infection can be seen in immunocompromised patients. N. asteroides is the predominant pathogen associated with disseminated diseases. We report 2 cases of pulmonary nocardiosis admitted with disseminated infection, caused by rare species of Nocardia: Nocardia transvalensis and Nocardia cyriacigeorgica.

Brucella peritonitis in a patient on continuous ambulatory peritoneal dialysis with acute brucellosis.

Peritonitis is an uncommon complication of brucellosis. Brucella peritonitis in chronic ambulatory peritoneal dialysis (CAPD) patients has not been reported before. A male patient is presented with peritonitis caused by Brucella melitensis who was on CAPD. The source of infection was thought to be unpasteurized, unsalted cheese eaten a month before the onset of symptoms. At the beginning, antibiotic therapy with doxycyline and rifampicin led to a rapid clinical improvement, with disappearance of the organism in the peritoneal fluid. However, peritonitis relapsed after discontinuation of antimicrobial therapy. Successful management required a combination of medical therapy and removal of the Tenckhoff catheter.

The role of infection and free oxygen radical damage in reflux nephropathy: an experimental study.

PURPOSE: We compared the effects of sterile and infected urine on reflux nephropathy in rabbits with experimental vesicoureteral reflux. MATERIALS AND METHODS: We used 2-month-old male New Zealand rabbits in this study. Group 1 (5 rabbits) served as the control, group 2 (7) was the vesicoureteral reflux plus sterile urine group and group 3 (8) was the reflux plus infected urine group. Cystography and 99mTc-dimercapto-succinic acid renal scintigraphy were performed before the reflux procedure. To create unilateral vesicoureteral reflux the roof of the right intravesical ureter was incised. Escherichia coli suspension (2 ml.), 105 E. coli in 1 ml.) was introduced into the bladder in addition to the reflux procedure in group 3. Right vesicoureteral reflux was confirmed by cystography 2 weeks after reflux. Dimercapto-succinic acid scintigraphy was performed at 3 weeks and the animals were sacrificed and examined. Free oxygen radical damage was investigated by measuring malondialdehyde levels in renal tissue. ANOVA and Scheffe's test were used for statistical analysis. RESULTS: Histopathological evaluation of the right kidney from group 2 rabbits showed mild interstitial fibrosis and mononuclear cell infiltration. The right kidney from group 3 rabbits showed apparent periglomerular fibrosis, tubular atrophy and dilatation, severe interstitial scarring and fibrosis with mononuclear cell infiltrate. There were marked histopathological changes in the right kidney of group 3 rabbits. The absolute percent dose uptake was unchanged in group 2 rabbits (p >0.05). There was significantly decreased uptake in refluxing kidneys and increased uptake in the contralateral nonrefluxing kidneys after vesicoureteral reflux in group 3 rabbits. The malondialdehyde level in the right renal tissue of group 3 was significantly higher than that in controls and in group 2 (p <0.05). The malondialdehyde level in the sterile reflux group did not differ significantly from that in the control group (p >0.05). CONCLUSIONS: The results of this study show that free oxygen radical damage in the presence of infection has an important role in reflux nephropathy.