Identification of PER-1 extended-spectrum beta-lactamase producing Pseudomonas aeruginosa clinical isolates of the international clonal complex CC11 from Hungary and Serbia.

PER-1 extended-spectrum beta-lactamase-producing Pseudomonas aeruginosa clinical isolates from Budapest, Hungary, and Belgrade, Serbia, were characterized by molecular methods. Two PER-1-positive isolates were recovered from sporadic cases in Budapest and a small cluster of PER-1-positive infections involving four patients were identified at a Belgrade hospital. A class 1 integron harbouring a bla(OXA-2)beta-lactamase gene and four other gene cassettes was detected in both the Budapest and the Belgrade isolates. The two P. aeruginosa isolates from Budapest also carried another class 1 integron containing bla(OXA-74), aac(6')-Ib-cr and cmlA7 genes in its variable region. The aac(6')-Ib-cr fluoroquinolone-acetylating aminoglycoside acetyltransferase gene is described here for the first time in P. aeruginosa. Multilocus sequence typing (MLST) revealed that the PER-1 positive P. aeruginosa isolates identified in this study display ST235, a sequence type that belongs to clonal complex CC11. Two bla(PER-1)-positive P. aeruginosa reference isolates from France and Belgium could also be assigned to complex CC11 by MLST. Our results underscore the role of complex CC11 in the dissemination of bla(PER-1) among P. aeruginosa clinical isolates.

Nosocomial bloodstream infections in ICU and non-ICU patients.

BACKGROUND: Nosocomial bloodstream infections (BSI) create a serious health problem in hospitals all over the world. The objectives of our study were to explore putative disease markers and potential risk factors with nosocomial BSI in patients in intensive care units (ICU) and non-ICU patients and to determine risk factors associated with increased 28-day mortality rate in patients with nosocomial BSI acquired in combined medical-surgical ICU. However, the major purposes of this report were to identify epidemiologic differences between nosocomial BSI acquired in ICU and non-ICU, as well as analyses outcomes for patients with nosocomial BSI acquired in ICU. METHODS: A 1-year prospective cohort study was performed to determine the incidence of nosocomial BSI in hospitalized patients. Patient characteristics, risk factors related to health care, and source of infection of patients with BSI acquired in non-ICU were compared with those patient with BSI acquired in ICU. Also, nested case-control study of patients to nosocomial BSI acquired in ICU was performed to evaluate outcome. Patients were identified by active surveillance and positive blood culture during the study period. RESULTS: The incidence of nosocomial BSI was 2.2 per 1000 admission in non-ICU patients and 17.4 per 1000 admission in ICU patients. The 28-day crude mortality rate was 69% in ICU patients. A multivariate model showed that nasogastric tube (RR, 25.1; 95% CI: 3.845-163.85; P=.001), mechanical ventilation (RR, 13.04; 95% CI: 1.974-96.136; P=.008), and H2 blockers (RR, 12.16; 95% CI: 1.748-84.623; P=.012) were more prevalent among patients with BSI acquired in ICU, and aggressive procedures (RR, 8.65; 95% CI: 1.70-44.00; P=.009) were more prevalent among patients with BSI acquired in non-ICU patients. Risk factors independently associated with increased 28-day mortality rate in ICU patients were mechanical ventilation (OR, 8.63; 95% CI: 1.5-49.8; P=.016) and SAPS II >40 (OR, 6.0; 95% CI: 1.0-35.7; P=.049). The most common isolated nosocomial BSI pathogens (in both groups of patients) were coagulase-negative staphylococci (21%), Staphylococcus aureus (14%), and Klebsiella species (13%). Klebsiella species was the only organism independently influencing the poor outcome of nosocomial BSI in ICU patients (OR, 4.3; 95% CI: 1.2-15.3; P=.022). CONCLUSIONS: Our results show epidemiologic differences between non-ICU and ICU BSI. Also, this study suggests that severity of underlying host conditions, mechanical ventilation, and microbial agents (Klebsiella species) affect the outcome of NBI in patients in ICU.

[Epidemiological characteristics of nosocomial bloodstream infections and their causes].

BACKGROUND/AIM: Nosocomial bloodstream infections (BSI) contribute to grater morbidity and mortality rates, as well as to increasing length of hospital stay and health care costs. All patients with nosocomial BSI identified during the one-year period were studed to identify microbiological factors associated with these infections. METHODS: A one-year prospective cohort study was performed in patients in intensive care units (ICU), and non-ICU patients. The patients were identified by active surveillance and positive blood cultures during the study period. The definitions of nosocomial BSI of the Center for Diseases Control and Prevention, Atlanta were used. Hospital laboratory detected growth in blood cultures, identified organisms, and performed susceptibility testing were in according with the American National Committee for Clinical Laboratory Standards. RESULTS: The incidence of nosocomial BSI was 2.2 per 1 000 admission in non-ICU and 17.4 per 1 000 admission in ICU patients. The 28-day crude mortality rate was 44.9%. There were 60.3% primary nosocomial BSI. Gram negative organisms accounted for 50%, gram-positive organisms accounted for 44.9%, and 4.1% were caused by fungi. The most common pathogens were coagulase-negative staphylococci (21.4%), Staphylococcus aureus (14.3%), Klebsiella spp. (13.3%), Pseudomonas aeruginosa (8.2%), Acinetobacter spp. (7.1%). Methicillin resistance was detected in 64.3% of S. aureus and 100% of coagulasa-negative staphylococci. Vancomycin resistance in enterococci and staphylococci was not detected. The proportion of ceftazidim resistance among K. pneumoniae isolates was 92%. CONCLUSION: This study might help to better understanding not only the characteristics of BSI, but also the featares of their causes, primarily the resistance of coagulase-negative staphylococci and S. aureus to methicillin, and of K. pneumoniae to ceftazidime.

[Antibiotic resistance in hospital strains of Enterococcus faecalis and Enterococcus faecium]. / Rezistencija bolnickih sojeva Enterococcus faecalis i Enterococcus faecium na antibiotike.

The aim of this study was to determine the resistance of Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) to penicillin, ampicillin, vancomycin, teicoplanin, gentamicin (high level), streptomycin (high level), oxytetracycline, chloramphenicol, rifampin, erythromycin, ciprofloxacin, norfloxacin, and nitrofurantoin from clinical specimens during 1999. The resistance of enterococci to antibiotics was determined by disk diffusion and dilution methods according to the American National Committee for Clinical Laboratory Standards guidelines. The production of beta-lactamase was determined by nitrocefin disks. In E. faecalis and E. faecium isolates (n = 111 and n = 48) the frequency of the resistance to both penicillins was 0.9% and 89.6%, respectively. All enterococci isolates were beta-lactamase negative. Only one strain of E. faecium was vancomycin resistant (Van A fenotype). Among E. faecalis isolates (n = 109) high level gentamicin resistance (HLGR), high level streptomycin resistance (HLSR), and resistance to both agents was 52.3%, 50.4%, and 43.7%, respectively. Among E. faecium isolates (n = 48) HLGR, HLSR, and to both agents were 68.7%, 75%, and 62.5% respectively. The majority of E. faecium isolates were resistant to both penicillin and ampicillin. E. faecalis remained susceptible to penicillins. Moreover, there was a very high incidence of enterococci resistant to high level aminoglycosides.

[Frequency and colonization rate of intravascular catheters]. / Ucestalost i stepen kolonizacije intravaskularnih katetera.

Clinical signs are not sufficiently reliable for establishing diagnosis of intravascular catheter-related infection. Therefore, microbiological confirmation, based on the culture of the catheter tip after its removal, is necessary in diagnosing the infection. The aim of this study was to determine the frequency and the degree of microbial colonization of intravascular catheters (IVK), and the risk for the onset of sepsis, by using qualitative, semiquantitative (roll plate) and quantitative (vortexing) catheter culture techniques. During the period April 2001-December 2002, 289 intravascular catheters were cultured. A total of 284 microorganisms were isolated from 217 (75%) culture-positive catheters. The frequency of isolation of some organisms was the following: coagulase-negative staphylococci (CNS) 41%, Staphylococcus aureus 19%, Enterococci spp 6%, other gram-positive microorganisms 9%, gram-negative microorganisms 21%, and fungi 4%. In 35 catheters, cultures were polymicrobial; two microorganisms were found in 25 cultures and three were found to be in 10 cultures. There were 122 (46%) intravascular catheters, which were found significantly colonized. A high rate of positivity and a high rate of S. aureus isolates and gram-negative bacteria indicate the need of establishing the exact microbiological diagnosis of these infections, and the rigorous undertaking of adequate control and preventive measures.

[The frequency of resistance to antibiotics of most frequently isolated bacteria from blood cultures during the period 1997-2002]. / Ucestalost rezistencije na antibiotike medu najcesce izolovanim bakterijama iz hemokultura u periodu 1997-2002. Godina.

The aim of this study was to determine the frequency of resistance to antibiotics of the most frequently isolated bacteria from blood cultures of hospitalized patients during the period 1997-2002. The resistance to antibiotics was determined by disk diffusion method according to National Committee for Clinical Laboratory Standards procedures. The majority of staphylococci isolates were resistant to methicillin, and the proportion of methicillin-resistant Staphylococcus aureus was stable (76.8-81.6%), during the follow-up period. None of the staphylococci isolates were resistant to vancomycin, but there was a very high incidence of high-level resistance of enterococci to aminoglycosides (47.2-72.2%). In 1998, only one strain among enterococci was resistant to vancomycin (Enterococcus faecium, VanA phenotype). Enterococcus spp isolates expressed variable frequency of resistance to ampicillin (15-40.1%) during the follow-up period. Among Enterobacteriaceae there were no isolates resistant to imipenem, but dramatic increase of the resistance to ceftriaxone was found from 35.9% in 1997 to 95.9% in 2002 (p<0.001). Extended spectrum beta-lactamases production was found in all the species of enterobacteria isolates. Resistance to imipenem was observed in Acinetobacter spp isolates in 2002 for the first time. Pseudomonas spp isolates expressed high and very variable resistance to all antibiotics tested during the follow-up period.

Evaluation of usefulness of single-strand conformation polymorphism method for rapid detection of rifampicin-resistant Mycobacterium tuberculosis.

The aim was to evaluate the Single-Strand Conformation Polymorphism method as a potential tool for rapid detection of rifampicin-resistant strains by the use of 39 rifampicin-resistant Mycobacterium tuberculosis strains isolated in Serbia. SSCP analysis on acrylamide gel detected 56.4% of the rifampicin-resistant M. tuberculosis strains and showed the inability to detect one of the most frequent mutations, TCG-->TTG mutation in codon 531 of the rpoB gene, which was shown by automated sequencing.

[Surveillance of bacterial causes of hospital infections during periods of war and peace]. / Nadzor nad pojedinim bakterijskim uzrocnicima bolnickih infekcija u periodu rata i mira.

Surveillance based on laboratory findings of bacteria isolated from hospitalized patients is an important activity in epidemiologic surveillance of nosocomial infections. It provides the insight into the circulation and management of some causative agents of nosocomial infections in hospitals, which facilitates defining of proper measures for the prevention and suppression of nosocomial infections caused by these agents. The aim of this study was to analyze and compare surveillance data collected in Military Medical Academy (MMA) during June 1999 (the period of war), and June 2000 (the period of peace). Isolation frequency of bacteria that were the most common agents of nosocomial: Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Acinetobacter spp. and Enterococcus spp., was monitored in patients from 5 various surgical wards of MMA. In the war period, the increase of number of isolates of all these bacteria was registered, but the increase of isolated Acinetobacter spp. was the most significant. The total number of isolates was greater in June 1999, in comparison to June 2000. Most isolates were recovered from wound cultures, when the increased number of Enterococcus spp. Methicillin-resistant Staphylococcus aureus isolated from the blood was registered. In the period of peace isolates of Pseudomonas aeruginosa manifested reduced resistance to quinolones, imipenem and 3rd generation cephalosporins. Barrier infection control measures are necessary in preventing nosocomial transmission, particularly in the wartime. Thus, preventive medicine is important for performing efficient surveillance, and suggesting the adequate measures for prevention and repression of nosocomial infections, particularly in the period of war.

[Multiorgan tuberculosis]. / Multiorganska tuberkuloza.

Tuberculosis is an unusual infectious disease because of the latent period between the infection and the appearance of the disease may be prolonged for many weeks, months, or years as it is in case of the secondary tuberculosis. Tuberculosis in organs other than the lung has been observed for many years but has not always been recognized as tuberculosis, and it has been given many names. Extrapulmonary tuberculosis gained new importance, because it represented a progressively greater proportion of new cases. Multiple extrapulmonary sites were reported rarely except for one anatomical site, which was reported frequently. Extrapulmonary rates increase with age, so there are marked differences in age in specific rate patterns among the sites. Extrapulmonary tuberculosis occurred in respiratory organs other than lung, such as lymphatic, urogenital, and central nervous system, abdominal, osteoarticular, as well as tuberculosis of other organs such as skin, pericardium and endocrine glands. This case was reported to analyse clinical, morphologic and laboratory characteristics, method of diagnosis and the outcome in patients with multiorgan tuberculosis in order to explore the factors which might contribute to the decision making, concerning these forms of tuberculosis. Recent knowledge of pathogenesis was summarized as well as clinical presentation and the effects of cytokines produced by T lymphocytes and cellular population on antimycobacterial immune defences, and also susceptibility to tuberculosis. Mortality remains high and the treatment should start as soon as tuberculosis is suspected.