Diagnostic value of a P-fimbriation test in determining duration of therapy in children with urinary tract infections.

The patients were 117 children (aged 4 months to 14 years) with uncomplicated urinary tract infections caused by co-trimoxazole-sensitive Escherichia coli. The patients were randomly assigned to receive treatment with co-trimoxazole for 3 days (n = 58) or 7 days (n = 59). Urine was analyzed for bacteria before and immediately after treatment and again at 1 and 2 months. After 3 days' treatment, infection persisted in 14 of 31 patients with P-fimbriated strains of E coli and in 1 of 27 patients with non-P-fimbriated strains. After 7 days' treatment, infection persisted in 2 of 40 patients with fimbriated strains and in none of the 19 patients with nonfimbriated strains. One or 2 months after treatment, 3 days' treatment was rated successful in 26 of 27 patients with nonfimbriated strains and in none of the patients with fimbriated strains. Seven days' treatment was rated successful in all patients with nonfimbriated strains and in 32 of 40 patients with fimbriated strains. The results indicate that the length of treatment of urinary tract infections in children should be adjusted according to the presence of bacterial P-fimbriae in addition to the patients' clinical condition.

Antibiotic resistance among nosocomial isolates in a Croatian intensive care unit--results of a twelve-year focal surveillance of nosocomial infections.

Continuous 12-year (1990--2001) focal surveillance of the antibiotic resistance among the most common nosocomial pathogens (Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter sp., and Staphylococcus aureus) in 1325 Intensive Care Unit patients was performed. The surveillance period was divided in three 4-year time intervals (1990--1993, 1994--1997 and 1998--2001) and the prevalence of resistance was compared between intervals. Specimens included blood, urine and respiratory tract specimens. The incidence and trends of resistance to six antibiotics showed inconsistent results. Aminoglycoside resistance decreased among K. pneumoniae_isolates (gentamicin 83%, 72.7% and 49.6%; amikacin 50.9%, 51.5% and 18.2%) and Acinetobacter sp. strains (amikacin 77%, 63.4% and 58.2%) but increased in P. aeruginosa (amikacin 27.5%, 63.3% and 44.1%). Overall, resistance to ceftazidime, ciprofloxacin, and imipenem increased but imipenem resistance is still low, particularly among Acinetobacter sp. isolates (0, 2.1% and 1.5%). However, imipenem resistance increased among P. aeruginosa (10.2%, 31.6%, 22.1%). The prevalence of methicillin resistance was high but did not change during the surveillance period (82.3%, 78.3% and 82.2%). The present study suggests a complex picture of the development of antibiotic resistance in a single ICU. Significant changes occur over time but they are unpredictable and do not show identical tendencies for different species and antibiotics.

Prevalence and antibiotic sensitivity pattern variations of bacterial isolates in different settings and different periods of time.

The problem of bacterial antibiotic resistance emerged as soon as the first antibiotics became available for clinical use. The aim of this study was to estimate differences in the prevalence and antibiotic sensitivity pattern of the most frequent isolates between two different hospitals (Sveti Duh General Hospital, Zagreb, und University Hospital of Traumatology, Zagreb), different wards of the same hospital (nephrology, urology and surgery of Sveti Duh General Hospital) and different periods of time (01. 03.--31. 12. 1993 and 01. 01.--31.07. 1995). E. coli was the most frequent urine isolate at the Sveti Duh Hospital, whereas more resistant K. pneumoniae was the most frequent urine isolate at the University Hospital of Traumatology. S. pneumoniae was the most frequent lower respiratory tract isolate in the Sveti Duh Hospital, whereas in the University Hospital of Traumatology P. aeruginosa and A. anitratus prevailed. In both hospitals, staphylococci were the most frequent blood culture isolates, but in gram-negative sepsis E. coli was the most frequent pathogen in the Sveti Duh Hospital, and S. marcescens in the University Hospital of Traumatology. Difference in the prevalence of microorganisms may have partially been due to the different patient profile in the two hospitals, but we showed that the antibiotic sensitivity pattern of the most frequent nosocomial pathogens P. aeruginosa and K. pneumoniae differed between different settings as well, and that this pattern may change with time. This clearly points to the need of continuous surveillance of the prevalence and antibiotic sensitivity pattern of microorganisms in local environment, which should be the basis for effective empiric therapy.

Phagocytic function in patients with recurrent urinary tract infections.

Phagocytes play an essential role in the host's defence against uropathogenic bacteria which are mostly extracellular pathogens. The functional capacity of peripheral blood phagocytes (predominantly polymorphonuclears, PMN) was investigated in 47 patients (urethrocystitis, acute or chronic pyelonephritis) and in healthy persons. The random mobility of phagocytes was determined by measuring their spontaneous migration from a capillary tube. Using radioactively labelled sheep erythrocytes as targets and the phagocytes as effector cells, ingestion, digestion and extracellular cytotoxicity were determined. All the four phagocytic functions in patients were significantly lower than in healthy controls, especially in patients with chronic pyelonephritis. These results link reduced phagocytosis by blood phagocytes with recurrent urinary tract infections (UTI). Whether the defect is primary or secondary to infection (and only transient) should be the object of further studies.

[Methicillin-resistant Staphylococcus aureus (MRSA), a predictor of the end of the antibiotic era--diagnosis, epidemiology, therapy and dissemination prevention]. / Meticilin-rezistentni Staphylococcus aureus (MRSA), pretkazatelj kraja antibiotske ere--dijagnostika, epidemiologija, terapija i mjere sprjecavanja sirenja.

Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent nosocomial pathogen worldwide, especially in large teaching hospitals. After the beginning of the war in Croatia, we have noticed a substantial increase in MRSA incidence in our country too. Mechanisms of resistance to methicillin differ from those mediated by the beta-lactamase production, and strains resistant to methicillin are at the same time resistant to the whole group of beta-lactam antibiotics. These strains represent a great therapeutic problem because there is often no antibiotic but vancomycin to be used for the treatment of MRSA infections. Vancomycin is an expensive and in long term therapy not well tolerated antibiotic, so to prevent the spread of these resistant strains is of ultimate importance. Among the general precautions hand washing is the single most important preventive measure. For MRSA strains additional precautions like patient isolation and tagging of discharged patient's notes should be implemented as well.

[AIDS as an occupational disease in health care personnel]. / AIDS kao profesionalna bolest u zdravstvenih radnika.

Since the health-care workers are frequently exposed to human blood they are considered to be at greater risk for acquiring HIV (human immunodeficiency virus). Body fluids to which universal precautions apply include blood, vaginal secretions, semen, tissues, cerebrospinal fluid, synovial, pleural, peritoneal, pericardial and amniotic fluid. These fluids of all patients are considered potentially infectious for HIV, and so are all the patients undergoing invasive procedures. Appropriate barrier precautions (gloves, aprons, masks and a protective eyewear) should prevent the skin and mucosa exposure to blood or other body fluids. If, however, a health-care worker has a parenteral of the mucosa exposure to blood or other body fluids of a HIV positive patient he should be tested for HIV antibody immediately after exposure, 6 weeks, 12 weeks and 6 months post-exposure. Among a variety of antiretroviral chemotherapeutic agents, so far, in humans only zidovudine has shown efficacy in vivo.

[Monitoring bacterial resistance to antibiotics in the CroatianRepublic]. / Pracenje rezistencije bakterija na antibiotike u Republici Hrvatskoj.

In 1996 a Committee for antibiotic resistance surveillance in Croatia was founded by the Croatian Academy of Medical Sciences. In this study antibiotic surveillance results for the period June 1-December 31, 1997 from 12 microbiology laboratories throughout Croatia are presented. Sensitivity to antibiotics was determined by disk diffusion method for the following bacteria: Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus spp., Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa. In general, high proportion of resistant isolates was recorded throughout Croatia, although some regional variations were noticed. Mean resistance of pneumococci to penicillin was 38%, in S. aureus resistance to methicillin was 47%, and 3rd generation cephalosporin-resistance in E. coli was 6% and in Klebsiella spp. 21%. In P. aeruginosa resistance to gentamicin averaged 50%, to imipenem 13% and to ceftazidim 8%. Future aims of the Committee are to continue routine antibiotic resistance surveillance during certain periods every year, and to estimate clinical significance of resistant bacteria, detect mechanisms of resistance and improve the quality of laboratory work through education and quality control projects.

Analysis of an outbreak of non-phage-typeable methicillin-resistant Staphylococcus aureus by using a randomly amplified polymorphic DNA assay.

A cluster of methicillin-resistant Staphylococcus aureus (MRSA) infections among patients on an intensive care unit (ICU) was detected by routine infection control surveillance. In the period from 5 January to 22 June 1995, 10 patients on the ICU and a further 6 patients (5 on one ward that had received colonized patients transferred from the ICU) were affected by MRSA strains with the same antibiotic susceptibility patterns. Seven (44%) of these 16 colonized patients developed MRSA bacteremia. MRSA isolates with the same characteristics were also found on the hands of one member of the ICU staff. The isolates were untypeable by phage typing, but 15 of 17 outbreak strains analyzed genetically had identical randomly amplified polymorphic DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) profiles. A single strain of MRSA that was nontypeable by phage typing and that was isolated on the ICU on 1 January and six nontypeable and epidemiologically unrelated MRSA isolates all had RAPD profiles distinct from that of the outbreak strain. Implementation of strict infection control measures stopped the further spread of MRSA on the ICU, the affected general ward, and seven other wards that received MRSA carriers from the ICU. Although nontypeable by phage typing and not previously recognized as an epidemic strain, this strain of MRSA was readily transmissible and highly virulent. RAPD typing was found to be a simple, rapid, and effective method for the epidemiological investigation of this outbreak, and performance of typing by this method was simpler and less time-consuming than that of typing by PFGE. RAPD typing may have more general application for the study of S. aureus infections in hospitals.

Epidemiological analysis of methicillin-resistant Staphylococcus aureus in a Zagreb Trauma Hospital using a randomly amplified polymorphic DNA-typing method.

During a 1-month period in 1996, all inpatients and staff in the Zagreb Trauma Hospital were screened for methicillin-resistant Staphylococcus aureus (MRSA) carriage in order to control MRSA spread within the hospital. During the study period, 663 patients were admitted to the hospital, and screening prior to discharge revealed that 42 were colonised or infected with MRSA. Twenty-three (55%) of these would not have been detected if active screening had not been performed. Amongst 205 staff members, MRSA carriage was only found in one (0.5%) nurse. The prevalence and incidence of MRSA carriage varied significantly amongst the wards and was related to the length of hospital stay. One-third of the patients colonised or infected with MRSA had a history of previous admission to another hospital, and one-third were transferred to another institution after discharge. Thirty-nine of 42 MRSA isolates shared the same antibiotic sensitivity pattern, suggesting endemic spread of MRSA. However, randomly amplified polymorphic DNA molecular typing revealed four profiles, the most common involving 15 of 36 tested strains. There was no obvious clustering of epidemiological types by ward, except for the appearance of a single type on the burns unit, and it was likely that different strains had been introduced into the hospital by patient transfers from elsewhere. The results of this study indicate that a substantial proportion of MRSA carriers escape infection control measures if active screening is not performed. Based on the results of this study, steps have been taken to improve interhospital communication about the transfer of patients colonised with MRSA. Randomly amplified polymorphic DNA typing proved to be a useful aid to epidemiological investigations of MRSA.