M. Luczak

Biofilm production by clinical strains of Acinetobacter baumannii isolated from patients hospitalized in two tertiary care hospitals

Microbial biofilms are considered as virulence factors. During the present study, 34 clinical strains of Acinetobacter baumannii, isolated from patients hospitalized in two tertiary care hospitals, were examined for biofilm formation. These strains showed high variability in biofilm formation. Furthermore, no relation could be found between the ability of biofilm production and molecular type, carbapenem resistance, site of isolation of the clinical strains of A. baumannii and disease severity. Interestingly, in two cases an increase in biofilm formation could be detected in A. baumannii isolates cultured from the same patient upon prolonged hospitalization.

Urinary tract infections in the early posttransplant period after kidney transplantation: etiologic agents and their susceptibility.

OBJECTIVE Urinary tract infection (UTI) is among the most common infections in solid organ transplantation, especially in kidney transplantation. PATIENTS AND METHODS This study included 295 adult patients undergoing KTx between September 2001 and December 2007. All patients were followed prospectively for UTI during the first 4 weeks after surgery. Samples of urine were investigated by bacteriological cultures to identify microorganisms in accord with standard procedures. Susceptibility testing was performed using Clinical and Laboratory Standards Institute procedures. RESULTS Urine specimens (n=582) were obtained from 84.5% of 245 recipients during the first month after transplantation. Among the isolated bacterial strains (n=291), the most common were Gram-negative bacteria (56.4%) predominantly Serratia marcescens (32.3%) and Enterobacter cloacae (14.6%). Extended- spectrum beta-lactamase (ESBL+) strains were isolated in 52.5% of cases. Gram-positive bacteria comprised 35.7%; most commonly, high-level aminoglycoside resistant (HLAR; 87.8%) and vancomycin-resistant (VRE; 11%) Enterococci. There were fungal strains in 23 cases (7.9%). CONCLUSION Our study showed predominantly Gram-negative rods from the Enterobacteriaceae family comprising (84.8%) of Gram-negative isolates: 52.5% ESBL and resistant enterococci (87.5%) in Gram-positive isolates. The increased proportion of isolates of multi-drug-resistant bacterial agents which can cause severe UTIs may be due to our frequent use of ceftriaxone for perioperative bacterial prophylaxis.

Epidemiology of clinical isolates of Candida albicans and their susceptibility to triazoles

The study comprised strains of Candida albicans isolated from patients hospitalised in a tertiary care hospital during a 2-year period. In total 851 strains were cultured, including 379 (44.5%) strains from internal medicine patients, 243 (28.6%) from surgical patients and 229 (26.9%) from patients in the surgical intensive care unit. The strains were tested for susceptibility to the triazoles: fluconazole and itraconazole. There were 523 (61.5%) strains susceptible, 11 strains (1.3%) showed intermediate susceptibility and 317 (37.2%) were resistant to fluconazole, while 403 (47.3%) strains were susceptible, 43 (5.1%) intermediately susceptible and 405 (47.6%) resistant to itraconazole. Regular surveillance of fungal resistance patterns should be carried out and there should be prudent use of hospital triazole usage.

Epidemiology and prevalence of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis in patients with diabetic foot ulcers: focus on the differences between species isolated from individuals with ischemic vs. neuropathic foot ulcers.

We examined whether foot ischemia or neuropathy with diabetic foot ulcer (DFU) promote selection of staphylococci species, evaluated frequency of MRSA and MRSE among strains yielded from patients with DFU and assessed multidrug resistance of isolates. Patients with DFU and foot osteomyelitis were divided into ischemic foot ulcer (IFU, n=21) and neuropathic foot ulcer (NFU, n=29) groups. Frequency of Staphylococcus epidermidis yielded from curettage of IFU was higher compared with NFU (P<0.05). S. epidermidis was also more frequently isolated from the toe web surface of patients with IFU compared with NFU (55% vs. 17.9%, respectively) and healthy volunteers (HV, n=20) (17.6%, P<0.05). These mostly MRSE strains (83.3-100%) originating from DFU patients were multidrug resistant (88.8%). Also, most of MRSA isolates were multidrug resistant (70.3%). Higher rates of MSSA from DFU patients than HV showed resistance to antimicrobials. This is the first report indicating that diabetic patients with IFU differ with NFU patients in higher frequency of S. epidermidis skin colonization and ulcer infection. We suggest that IFU should be defined as separate disease state of DFU and S. epidermidis should be appreciated as a nosocomial pathogen.

Surgical site infections in the early posttransplant period after simultaneous pancreas-kidney transplantation.

OBJECTIVE Urinary tract infection (UTI) is among the common infection in simultaneous pancreas-kidney transplantation (SPKT). PATIENTS AND METHODS The study included 26 adult patients undergoing SPKT between September 2001 and December 2006. All the patients were followed prospectively for UTI during the first 4 weeks after surgery. Urine samples were investigated for bacteriologic cultures. The micro-organisms were identified in accordance with standard bacteriologic procedures. Susceptibility testing was carried out using Clinical and Laboratory Standards Institute (CLSI) procedures. RESULTS Among 77 urine specimens obtained from all recipients during the first month, there were 30 isolated bacterial strains. The most common were Gram-positive bacteria (53.3%) with predominance of enterococci (75%) associated with high levels of aminoglycoside resistant strains (HLAR; 58.3%) and vancomycin-resistant strains (VRE; 25%). Gram-negative bacteria were detected in 46.7% of positive cultures. CONCLUSIONS In our study, enterococci predominated as 75% of Gram-positive isolates. The increased proportion of multi-drug-resistant bacteria, which can caused severe UTI in patients after SPKT, may be due to the frequent use of prophylaxis of bacterial infections in patients.

Epidemiology and susceptibility to antifungal agents of fungi isolated from clinical specimens from patients hospitalized in the Department of General and Liver Surgery of the Medical University of Warsaw

The aim of this study was to analyze the type and antibiotic susceptibility of fungi isolated from clinical specimens obtained from patients hospitalized in the Department of General, Transplantation and Liver Surgery of the Medical University of Warsaw between 2000 to 2002. Among the 326 clinical samples found to be positive on mycological culture, 356 strains were cultured. The most common isolates were yeastlike fungi of the genus Candida 334 (93.8%), while others included 33 other types (6.2%). The most commonly isolated species were Candida albicans, 194 strains (54.5%); Candida glabrata, 68 (19.1%); Candida krusei, 20 (5.6%); Candida inconspicua, 20 (5.6%); Candida tropicalis, 17 (4.8%); and Candida parapsilosis, 6 (1.7%). Upon testing for susceptibility to antifungal agents, all strains were susceptible to amphotericin B, while 43.8% of strains showed intermediate susceptibility to fluconazole and 25.3%, to itraconazole. Control of fungal infections in transplant and in immunocompromised patients is hindered by the low percentage of strains susceptible to commonly used antifungal agents, particularly of the triazole group.

Multidrug resistance in bacterial isolates from blood cultures of haematology patients

The bacteria most frequently isolated from blood cultures of haematology patients in Warsaw were staphylococci (58.0%), Enterobacteriaceae (18.6%), non-fermenting rods (6.9%), enterococci (4.3%) and anaerobes (4.3%). Coagulase-negative staphylococci were the most common species isolated (92.7%) with 83.2% of these strains resistant to methicillin. Among enteric bacteria, 17.3% strains produced extended-spectrum-beta-lactamases. All eight isolates of enterococci showed high level resistance to aminoglycosides.

Etiologic agents of bacteremia in the early period after simultaneous pancreas-kidney transplantation.

BACKGROUND Bacteremia is among the known complications in simultaneous pancreas-kidney transplantation (SPKT). This study evaluated the frequency of microbial isolates and their susceptibility profiles among cultures of clinical samples obtained from blood and from the tips of blood vessel catheters of 26 SPKT recipients suspected of bacteremia in the early posttransplant period. PATIENTS AND METHODS Data on microbiologic blood cultures of 26 adult patients undergoing SPKT were collected prospectively from 2001 to the end of 2006. The isolation and identification of cultured microorganisms were performed according to standard microbiological procedures and commercially available tests. The susceptibility of the strains to antibacterial agents was established by the Clinical and Laboratory Standards Institute guidelines. RESULTS All patients were followed prospectively for the first 4 weeks after surgery. Among 66 clinical samples, there were 23 microbial isolates from blood samples of 17 recipients and catheter tips of 12 recipients. The most common isolates were Gram-positive bacteria (73.9%) with domination of staphylococci (64.7%) and MRCNS strains (81.8%). Gram-negative bacteria comprised 17.4% of positive cultures, whereas yeast-like fungi, 8.7% with a predominance of Candida glabrata. CONCLUSION Our study showed predominately Gram-positive bacteria in 73.9% of isolates. The increased proportion of multi-drug-resistant bacteria and fungi to antimicrobial agents may be due to the frequent use of these agents for prophylaxis of bacterial infections in patients.

Urinary tract infections in the early posttransplant period after liver transplantation: etiologic agents and their susceptibility.

BACKGROUND We performed an analysis of etiologic agents for urinary tract infections in the early posttransplant period after orthotopic liver transplantation (OLT) in adult recipients. PATIENTS AND METHODS The study covered the first 4 weeks after OLT of 190 patients from September 2001 to the end of 2007. Immunosuppression consisted of steroids and tacrolimus. Antimicrobial prophylaxis was piperacillin/tazobactam, fluconazole, and SBD. Urine samples were cultured to identify microorganisms in accord with standard microbiological procedures and to test susceptibility using Clinical Laboratory and Standards Institute guidelines. RESULTS Urine specimens (n=539) examined from 185 recipients (97.4%) showed 210 microbial strains. The most common were Gram-negative (n=131; 62.4%) with predominance of Escherichia coli (28.2%), Enterobacter cloacae (19.1%), and Acinetobacter baumannii (11.4%). Extended-spectrum β- lactamases (ESBL(+)) strains were isolated in 38.5% of cases. Gram-positive bacteria comprised 28.6% (n=60): The most common strains were enterococci (85% including HLAR 80.4% and VRE 17.6%] and staphylococci 11.8% [MRSA/MRCNS; 100%]. There were 19 (9%) fungal strains. CONCLUSIONS In general, the identification in urine samples of multi-drug-resistant bacterial and fungal strains in patients after OLT such as ESBL(+) 38.5%; HLAR 80.4%; VRE 17.6%; and MRSA/MRCNS 100% requires better infection control.

18 Fungal infections of blood in patients undergoing immunosuppressive therapy after solid organ transplantation: Epidemiology and susceptibility of the fungal strains

positive cocci 71 isolates. The coagu[ase-negative staphylococci 52 isolates (the Methici[[in Resistant Coagu[ase-Negative Staphylococci MRCNS strains were detected). The Enterococcus spp. occurred in 9 isolates (the High Level Aminog[ycoside Resistant HLAR enterococci strains were cub tured). The Enterobacteriaceae family 16 isolates and 15 isolates of Gram-negative nonfermenting rods were detected, some of Gram-negative rods were Extended-Spectrum Beta-Lactamases ESBL (+) strains. Conclusions: 1. The domination of Gram-positive cocci in bacteriemia is caused by coagu[asenegative staphylococci (a frequent cause of nosocomia[ catheter-related bloodstream infections) and may be due to the use of antimicrobia[ prophylaxis which reduces Gram-negative bacteria[ strains. 2. The increased rate of isolation of Multi-Drug-Resistant (MDR) bacteria to antimicrobia[ agents may be due to the frequent use of these agents for prophylaxis of bacteria[ infections in liver transplant recipients. These MDR bacteria[ strains caused severe blood infections in patients after LT.