First report on PVL-positive methicillin-resistant Staphylococcus aureus of SCCmec type V, spa type T441 in Croatia.

The aim of the study was to investigate the molecular epidemiology of community- associated MRSA in Primorsko-Goranska County of Croatia during a six-year period(2001-2007). In period from 2001 and 2007, 46 MRSA isolates were collected in Rijeka, strains were subjected to susceptibility testing according to CLSI guidelines, mecA gene detection and SCCmec typing as well as detection of PVL. Strains were typed by Pulse Field Gel Electrophoresis (PFGE) and spa typing. All isolates were susceptible to vancomycin, linezolid, mupirocin, nitrofurantoin, only one strain was resistant to fusidic acid and co-trimoxazole. Results of SCCmec typing showed the presence of SCCmec type IV in 26 MRSA strains, SCCmec type V in three strains, and 13 strains comprised SCCmec I. SCCmec type II and III were not observed. Four MRSA strains were non-typeable by applied SCCmec typing methods. PVL was detected in 4 strains, two SCCmec IV and two SCCmec V. PFGE analysis, grouped MRSA strains into six similarity groups and 18 singletons. Dominating spa types in this collection of strains were t015, with 15 strains, followed by t041(N=7), t051,(N=2 ), t2850(N=2), t008(N=2)and single isolates t441, t002, t448, t018, t019, t355, t390, t026, t449, t148. We also detected two new spa types, t3510 and t3509, respectively. This is the first report on SCCmec type V in Croatia, and, to our knowledge, first report of PVL-positive mehicillin-resistant Staphylococcus aureus SCCmec type V and t441(ST59-MRSA-V) in this part of Europe.

Nationwide Survey of Klebsiella Pneumoniae Strains Producing CTX-M Extended-spectrum ß-lactamases in Croatia.

Extended-spectrum ß-lactamases (ESBL) producing bacteria have been increasingly reported in both hospital and community patients. Production of ESBLs is the major mechanism of resistance to oxymino-cephalosporins and aztreonam in Gram-negative bacteria. Recently a new family of ESBLs with predominant activity against cefotaxime (CTX-M ß-lactamases) has been reported. Over 80 CTX-M enzymes have been described so far, which can be grouped into five main subgroups according to amino acid sequence identity (CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9 and CTX-M-25). In some countries, CTX-M ß-lactamases are the most prevalent types of ESBLs, for instance in Russia, Greece, Spain, Switzerland, Japan, Taiwan, China and Argentina. These enzymes have been identified in countries near Croatia such is Italy, Hungary and Austria. The aim of this study was to determine the prevalence and the types of CTX-M ß lactamases produced by Klebsiella pneumoniae clinical isolates collected from October 2006 to January 2007 from both community- and hospital-based isolates were included (Figure 1.). 128 ESBL isolates were subjected to further analysis: screening with double disc diffusion test and confirmed by ESBL E test.

Influenza and hepatitis B vaccination coverage among healthcare workers in Croatian hospitals: a series of cross-sectional surveys, 2006-2011.

BACKGROUND: Healthcare workers (HCWs) are at an increased risk of exposure to and transmission of infectious diseases. Vaccination lowers morbidity and mortality of HCWs and their patients. To assess vaccination coverage for influenza and hepatitis B virus (HBV) among HCWs in Croatian hospitals, we conducted yearly nationwide surveys. METHODS: From 2006 to 2011, all 66 Croatian public hospitals, representing 43-60% of all the HCWs in Croatia, were included. Statistical analysis was performed using the Kruskal-Wallis analysis of variance, Dunn's multiple comparison analysis and the chi-square test, as appropriate. RESULTS: The median seasonal influenza vaccination coverage rates in pre-pandemic (2006-2008) seasons were 36%, 25% and 29%, respectively. By occupation, influenza vaccination rates among physicians were 33 ± 21%, 33 ± 22% among graduate nurses, 30 ± 34% among other HCWs, 26 ± 21% among housekeeping and the lowest, 23 ± 17%, among practical nurses (p < 0.01). In 2009-2010 season, seasonal influenza vaccination coverage was 30%, while overall vaccination coverage against pandemic influenza was fewer than 5%. Median vaccination coverage in the post-pandemic seasons of 2010-2011 and 2011-2012 decreased to 15% and 14%, respectively (reduction of 24% and 35%, respectively, p < 0.0001). Meanwhile, the median mandatory HBV vaccination coverage was 98%, albeit with considerable differences according to work setting (range 19-100%) and occupation (range 4-100%). CONCLUSIONS: We found substantial year-on-year variations in seasonal influenza vaccination rates, with reduction in post pandemic influenza seasons. HBV vaccination is satisfactory compared to seasonal influenza vaccination coverage, although substantial variations by occupation and work setting were observed. These findings highlight the need for national strategies that optimize vaccination coverage among HCWs in Croatian hospitals. Further studies are needed to establish the potential role of mandatory vaccination for seasonal influenza.

Efficacy of ozone on microorganisms in the tooth root canal.

The aim of this study was to examine the effect of ozone gas on the remaining bacteria after chemomechanical instrumentation of tooth root canal. The study was carried out at the Department of Endodontics and Restorative dentistry, School of Dental Medicine, University of Zagreb. A total of 37 tooth root canals from 23 teeth (10 incisors, 2 canines, 8 premolars and 3 molars) with a diagnosis of chronic apical periodontitis (17 untreated teeth and 6 retreatments) from 20 adult patients (11 females and 9 male) were selected. Endodontic samples consisted of 74 swabs from 37 canals. The first root canal swab was taken following a completed chemomechanical instrumentation by a sterile paper point after rinsing the root canal with a sterile saline solution. The canal was dried and treated with ozone gas for 40 seconds (HealOzone, Kavo, Germany). After the ozone treatment the canal was rinsed with a sterile saline solution a second swab was taken. The swabs were stored in transport media until cultivation. Microbiological identification was performed by macromorphological, micromorphological, commercial biochemical test microbiological analysis and bacteria count. A significant decrease in the number of bacteria (p < 0.001) was found after the ozone treatment: the total number of bacteria was 82%, 67% of aerobic and 93% of anaerobic bacteria. When analysing individually, a significant decrease was found for Streptococcus mitis and Propionibacterium acnes (p < 0.05). The results of this study shows the efficacy of ozone on the bacterial count reduction in the root canal treatment.

The screening of methicillin-resistant staphylococcus aureus in vascular surgery patients: a comparison of molecular testing and broth-enriched culture.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a major global health care-associated pathogen. This study sought to examine the prevalence of MRSA in patients who were admitted to a vascular surgery ward during a 3-month period. METHODS: MRSA screening was accomplished through the acquisition of nasal, throat and perineal swabs. These swabs were placed in tryptic soy broth that had been supplemented with 6.5% NaCl and incubated for 24 h. The resulting isolates were subcultured on agar plates containing 5% sheep blood. The BD GeneOhm MRSA assay for screening swabs was performed in accordance with the manufacturer's instructions. RESULTS: A total of 58 patients were included in the study and swabs from 232 sites were obtained during the sampling period. MRSA was detected in 33 samples of 12 patients during the study period; thus, there was a 20.6% prevalence of patients who were recognized as MRSA carriers. There were discrepancies between the results of classical bacteriological screening and molecular MRSA detection methods in 8 of the patients. CONCLUSIONS: Nasal, throat and perineal MRSA screening can detect the carriage of this pathogen and allow for the timely use of appropriate infection control measures. The choice of screening techniques poses a challenge; it has been demonstrated that molecular detection methods should be performed with great sensitivity, specificity and, most importantly, speed. The cost of the PCR screening method is the only disadvantage of this approach.

Value of rapid aetiological diagnosis in optimization of antimicrobial treatment in bacterial community acquired pneumonia.

In 80 adult patients with community acquired pneumonia (CAP) conventional microbiological methods, polymerase chain reaction (PCR) and serum C-reactive protein (CRP) levels were performed and the appropriateness of the empirical antimicrobial treatment was evaluated according to bacterial pathogen detected. The aetiology was determined in 42 (52.5%) patients, with Streptococcus pneumoniae as the most common pathogen. PCR applied to bronchoalveolar lavage (BAL) provided 2 and PCR on sputum samples 1 additional aetiological diagnosis of CAP The mean CRP values in the S. pneumoniae group were not significantly higher than in the group with other aetiological diagnoses (166.89 mg/L vs. 160.11 mg/L, p = 0.457). In 23.8% (10/42) of patients with determined aetiology, the empirical antimicrobial treatment was inappropriate. PCR tests need further investigation, particularly those for the atypical pathogens, as they are predominant in inappropriately treated patients. Our results do not support the use of CRP as a rapid test to guide the antimicrobial treatment in patients with CAP.

[Comparative urinary bactericidal activity of oral antibiotics against gram-positive pathogens]. / Usporedna urinarna baktericidna aktivnost oralnih antibiotika prema gram-pozitivnim urinarnim patogenima.

In routine bacteriological laboratories the antibacterial activity of antibiotics is determined by in vitro testing, usually by disk-diffusion test. However, in vitro testing does not always reflect antibacterial efficiency of antibiotics in vivo. In this investigation, the urine samples obtained in a single oral dose pharmacokinetic study were examined for their bactericidal activity against a range of relevant Gram-positive urinary tract pathogens. Urinary bactericidal activity of linezolid had been previously compared with ciprofloxacin but not with other oral antibiotics such as beta-lactams. Linezolid showed satisfactory urinary bactericidal titres throughout the whole testing period against all Gram-positive cocci. Fluoroquinolones displayed high and persisting levels of urinary bactericidal activity against staphylococci, but their activity against enterococci was weaker. According to the results of ex-vivo testing amoxycillin could be recommended only for infections caused by E. faecalis. Amoxycillin combined with clavulanic acid can be considered as a therapeutic option for infections caused by S. saprophyticus and E. faecalis. Older cephalosporins had high titres only against S. saprophyticus. Their drawback is a short elimination half-time in urine resulting in rapid decrease of urinary bactericidal titers during dosing interval. Furthermore, they do not show activity against enterococci due to their intrinsic resistance to cephalosporins.

Clinical impact of antimicrobial resistance in European hospitals: excess mortality and length of hospital stay related to methicillin-resistant Staphylococcus aureus bloodstream infections.

Antimicrobial resistance is threatening the successful management of nosocomial infections worldwide. Despite the therapeutic limitations imposed by methicillin-resistant Staphylococcus aureus (MRSA), its clinical impact is still debated. The objective of this study was to estimate the excess mortality and length of hospital stay (LOS) associated with MRSA bloodstream infections (BSI) in European hospitals. Between July 2007 and June 2008, a multicenter, prospective, parallel matched-cohort study was carried out in 13 tertiary care hospitals in as many European countries. Cohort I consisted of patients with MRSA BSI and cohort II of patients with methicillin-susceptible S. aureus (MSSA) BSI. The patients in both cohorts were matched for LOS prior to the onset of BSI with patients free of the respective BSI. Cohort I consisted of 248 MRSA patients and 453 controls and cohort II of 618 MSSA patients and 1,170 controls. Compared to the controls, MRSA patients had higher 30-day mortality (adjusted odds ratio [aOR] = 4.4) and higher hospital mortality (adjusted hazard ratio [aHR] = 3.5). Their excess LOS was 9.2 days. MSSA patients also had higher 30-day (aOR = 2.4) and hospital (aHR = 3.1) mortality and an excess LOS of 8.6 days. When the outcomes from the two cohorts were compared, an effect attributable to methicillin resistance was found for 30-day mortality (OR = 1.8; P = 0.04), but not for hospital mortality (HR = 1.1; P = 0.63) or LOS (difference = 0.6 days; P = 0.96). Irrespective of methicillin susceptibility, S. aureus BSI has a significant impact on morbidity and mortality. In addition, MRSA BSI leads to a fatal outcome more frequently than MSSA BSI. Infection control efforts in hospitals should aim to contain infections caused by both resistant and susceptible S. aureus.

Cotton textiles modified with citric acid as efficient anti-bacterial agent for prevention of nosocomial infections.

AIM: To study the antimicrobial activity of citric acid (CA) and sodium hypophosphite monohydrate (SHP) against gram-positive and gram-negative bacteria, and to determine the influence of conventional and microwave thermal treatments, on the effectiveness of antimicrobial treatment of cotton textiles. METHOD: Textile material was impregnated with CA and SHP solution and thermally treated by either conventional or microwave drying/curing treatment. Antibacterial effectiveness was tested according to ISO 20743:2009 standard, using absorption method. The surfaces were morphologically observed by scanning electron microscopy, while physical characteristics were determined by wrinkle recovery angles method (DIN 53 891), tensile strength (DIN 53 837), and whiteness degree method (AATCC 110-2000). RESULTS: Cotton fabric treated with CA and SHP showed significant antibacterial activity against MRSA (6.38 log10 treated by conventional drying and 6.46 log10 treated by microwave drying before washing, and 6.90 log10 and 7.86 log10, respectively, after 1 cycle of home domestic laundering washing [HDLW]). Antibacterial activity was also remarkable against S. aureus (4.25 log10 by conventional drying, 4.58 log10 by microwave drying) and against P. aeruginosa (1.93 log10 by conventional drying and 4.66 log10 by microwave drying). Antibacterial activity against P. aeruginosa was higher in samples subjected to microwave than in conventional drying. Antibacterial activity was reduced after 10 HDLW cycles but the compound was still effective. The surface of the untreated cotton polymer was smooth, while minor erosion stripes appeared on the surfaces treated with antimicrobial agent, and long and deep stripes were found on the surface of the washed sample. CONCLUSION: CA can be used both for the disposable (non-durable) materials (gowns, masks, and cuffs for blood pressure measurement) and the materials that require durability to laundering. The current protocols and initiatives in infection control could be improved by the use of antimicrobial agents applied on cotton carbohydrate polymer.

[Diagnostic approach and therapy for cytomegalovirus (CMV) infection following allogeneic stem cell transplantation]. / Dijagnosticki pristup, pracenje i lijecenje citomegalovirusne (CMV) infekcije nakon alogene transplantacije krvotvornih maticnih stanica.

In spite of improvements in diagnostics and prevention of CMV disease in recent decades, CMV infection still remains major concern in terms of diagnosis and therapy in recipients of allogeneic stem cells. Besides considerable morbidity with direct effects of CMV infection (hepatitis, gastrointestinal disease, pneumonia, retinitis), there are also indirect effects such as increased susceptibility to opportunistic infections and an increased risk of graft rejection and transplant-related mortality. Also, myelosuppression, nephrotoxicity and emergence of drug-resistant CMV strains may limit the use of antiviral agents for the control of CMV infection. The aim of this paper is to show the problems associated with CMV infection in recipients of allogeneic stem cells with special emphasis on diagnostic procedures and treatment or prophylaxis of CMV disease.

[Guidelines on hand hygiene in health care institutions]. / Smjernice za higijenu ruku u zdravstvenim ustanovama.

Healthcare associated infections (HCAI) are huge problem all over the world, and 5-10% of all hospitalized patients will develop infection during hospitalization. From the times of I. P. Semelweiss we know that clean hands are the most important single factor that can decrease the number of HCAI. World Health Organization (WHO) has recognised this problem and developed Guidelines for hand hygiene in healthcare institutions. This also was the reason of developing Croatian national Guidelines. The main goal of the Guidelines was to decrease number of HCAI associated with the hands of healthcare workers. These Guidelines are meant for all healthcare workers and other hospital staff who come to the direct contact with patients. An interdisciplinary team of experts developed these Guidelines using WHO Guidelines, other existing guidelines and literature reviews for hand hygiene. Grades of evidence for specific recommendations were determined using CDC/HICPAC grading system. Categorization is based on existing data, theoretical basis, applicability and economic impact. After a broad discussion in different professional societies, Guidelines were accepted. Guidelines include recommendations for hand hygiene indications, hand hygiene technique, surgical hand preparation, choosing hand hygiene preparations, skin care, nails, glove use, patients and visitors hand hygiene, role of education, as well as role of healthcare institution and role of government. Furthermore, in the Guidelines the concept of "Five moments for hand hygiene" is explained in detail, and main literature data are presented.

VIM-2 beta-lactamase in Pseudomonas aeruginosa isolates from Zagreb, Croatia.

The aim of this investigation was to characterize metallo-beta-lactamases (MBLs) in Pseudomonas aeruginosa isolates from Zagreb, Croatia. One hundred P. aeruginosa isolates with reduced susceptibility to either imipenem or meropenem were tested for the production of MBLs by MBL-Etest. The susceptibility to a wide range of antibiotics was determined by broth microdilution method. The presence of bla(MBL) genes was detected by polymerase chain reaction (PCR). Hydrolysis of 0.1 mM imipenem by crude enzyme preparations of beta-lactamases was monitored by UV spectrophotometer. Outer membrane proteins were prepared and analysed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Six out of 100 isolates were positive for MBLs by Etest. All strains were resistant to gentamicin, ceftazidime and cefotaxime, and all except 1 were resistant to imipenem. Six strains positive for MBLs by Etest were identified as VIM MBL-producers by PCR. Sequencing of bla(VIM) genes revealed the production of VIM-2 beta-lactamase in all 6 strains. This investigation proved the occurrence of VIM-2 beta-lactamase among P. aeruginosa strains from Zagreb, Croatia. VIM-2 beta-lactamase with similar properties has previously been described in another region of Croatia and in Italy, France, Spain, Greece, Taiwan and South Korea, suggesting that this type of enzyme is widespread in the Mediterranean region of Europe and in the Far East.

Emergence of Proteus mirabilis isolates producing TEM-52 extended-spectrum beta-lactamases in Croatia.

BACKGROUND: An increased frequency of extended-spectrum beta-lactamase (ESBL)-positive Proteus mirabilis isolates was observed recently in the Clinical Hospital Center Split in Croatia. The aim of this study was the molecular characterization of ESBLs in P. mirabilis isolates from this hospital. MATERIAL AND METHODS: Seven strains showing reduced susceptibility to ceftazidime were investigated. Antimicrobial susceptibility was determined using the broth microdilution method. ESBLs were characterized by PCR and sequencing of bla(ESBL) genes. Quinolone resistance determinants (qnr genes) were characterized by PCR. Genotyping of strains was performed by pulsed-field gel electrophoresis (PFGE). RESULTS: The presence of an ESBL was confirmed in all strains by a double-disk synergy test. All strains were resistant to amoxicillin, piperacillin, gentamicin, ciprofloxacin, chloramphenicol, sulfamethoxazole and trimethoprim, but susceptible to ceftazidime/clavulanic acid, piperacillin/tazobactam, cefoxitin, imipenem and meropenem; PCR sequencing using primers targeting bla(ESBL) genes revealed TEM-52 beta-lactamase. PFGE genotyping demonstrated the clonal relatedness of TEM-52-producing P. mirabilis strains isolated from different clinical samples and wards within the hospital. Bla(TEM-52) in 3 isolates was carried by a 70-kb conjugative plasmid. CONCLUSIONS: Our findings indicate the emergence of the TEM-52 enzyme among P. mirabilis in Croatia.

[Guidelines for prevention, control and treatment of infections caused by methicillin-resistant Staphylococcus aureus (MRSA): changes and updates of chapter 7.0: treatment of patients with MRSA infection]. / Smjernice za prevenciju, kontrolu i lijecenje infekcija koje uzrokuje meticilin-rezistentni Staphylococcus aureus (MRSA): izmjena i dopuna poglavlja 7.0.: lijecenje bolesnika s MRSA - infekcijom.

Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen throughout the world, and as well in Croatia. Therefore it was decided to develop guidelines with the aim to reduce the number of patients infected/colonized with MRSA in healthcare facilities and in nursing homes in Croatia, consequently reducing MRSA-related morbidity and mortality. An interdisciplinary team of experts developed these guidelines using existing international guidelines from different countries, and literature reviews about prevention, control, treatment and laboratory diagnosis of MRSA infections. Grades of evidence for specific recommendations were determined using CDC/HICPAC grading system. Categorization is based on existing data, theoretical basis, applicability and economic impact. After a broad discussion in different professional societies, Guidelines were accepted. In the meantime, several new possibilities appeared in the treatment of patients with MRSA infections in Croatia, so the Chapter 7.0 Treatment of patients with MRSA infections is changed and updated according to the new treatment possibilities. The rest of the Guidelines was not changed.

Occurrence of OXA-107 and ISAba1 in carbapenem-resistant isolates of Acinetobacter baumannii from Croatia.

Carbapenem-resistant isolates of Acinetobacter baumannii from intensive care units at Split University Hospital, Split, Croatia, were studied. Most (100 of 106) had ISAba1 inserted upstream of a bla(OXA-107) gene, encoding an unusual OXA-51-type oxacillinase. Pulsed-field gel electrophoresis revealed that the isolates formed three clusters belonging to the sequence group 2 (European clone 1) lineage.

Helicobacter pylori eradication therapy success regarding different treatment period based on clarithromycin or metronidazole triple-therapy regimens.

BACKGROUND: The study compares the eradication success of standard first-line triple therapies of different durations (7, 10, and 14 days). MATERIALS AND METHODS: A total of 592 naive Helicobacter pylori-positive patients were randomized to receive pantoprazole, amoxicillin, and clarithromycin or metronidazole for 14 days (PACl14 or PAM14), 10 days (PACl10 or PAM10), or 7 days (PACl7 or PAM7). H. pylori eradication was assessed by histological, microbiological, and rapid urease examination. RESULTS: The intention-to-treat (ITT) and per-protocol (PP) analyses have shown no overall statistically significant differences between the eradication success of PACl and PAM treatment groups (ITT p = .308, PP p = .167). Longer treatment duration has yielded statistically significant increase in eradication success for clarithromycin (ITT p = .004; PP p = .004) and metronidazole (ITT p = .010; PP p = .034) based regimens. Namely, PACl10, PACl14, and PAM14 protocols resulted in eradication success exceeding 80% in ITT and 90% in PP analysis. Primary resistance to clarithromycin and metronidazole equals 8.2% and 32.9%, respectively. Prolonging the metronidazole-based treatment duration in patients with resistant strains resulted in statistically significant higher eradication success. CONCLUSIONS: For all antimicrobial combinations, 14 days protocols have led to a significant increase of H. pylori eradication success when compared to 10 and 7 days, respectively. Prolonging the treatment duration can overcome the negative effect of metronidazole resistance. Only PAM14, PACl10 protocols achieved ITT success > 80% and should be recommended as the first line eradication treatment in Croatia.

Effect of aminglycoside administration on the occurrence and multiplication of resistant bacteria.

In the prospective study the susceptibility of 41 Escherichia coli strains and 55 Pseudomonas aeruginosa strains to gentamicin, netilmicin and amikacin was tested at a 2-year interval (period I April 1998 to March 1999, and period II April to July 2001). Genotyping was performed by pulsed-field gel electrophoresis, and a clone based on 80% or 90% similarity was determined for each of the study bacteria. In 24 (32.0%) clones, strains showed no variation over 2-year interval, supporting the hypothesis on a priori susceptible strains. Transformation from susceptibility in period I to resistance in period II was demonstrated in 5 (6.7%) clones, a pattern consistent with the concept of bacterial development of resistance under the influence of antibiotics. However, there were 10 (13.3%) clones whose strains exhibited an inverse pattern. Accordingly, two-way transformation of susceptibility took place during the study period. The utilization of the study aminoglycosides had no major impact on the variation of microbial susceptibility. Changes in microbial susceptibility were found to follow some regular patterns, which were not influenced by the study aminoglycosides. Two phenomena were observed: (i) there were stable clones that did not develop resistance in spite of selective antibiotic challenge; and (ii) changes of susceptibility in isolated bacteria from both inpatient and outpatient strains of the same clone were two-way and reversible.

Clonal dissemination of highly virulent extended-spectrum beta-lactamase-producing Escherichia coli strains isolated from the urine of non-hospitalised patients in Zagreb region.

Recent data suggest that extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli is an emergent cause of urinary tract infections in non-hospitalised patients in different countries. The aim of this study was to characterise ESBL-producing E. coli strains isolated from the urine of outpatients in the Zagreb region of Croatia. During the 5-month study period, a total of 2451 E. coli strains were isolated from the urine of non-hospitalised patients with significant bacteriuria. A total of 39 ESBL-producing E. coli strains (1.59%) were collected and characterised.

Coronal microleakage of two root-end filling materials using a polymicrobial marker.

The purpose of this study was to evaluate polymicrobial coronal leakage of mineral trioxide aggregate (MTA) and amalgam. There were 108 single-rooted teeth randomly divided into 3 groups of 32 teeth each and positive and negative control groups of 6 teeth and obturated with gutta percha and either Diaket (3M/ESPE, Seefeld, Germany), AH Plus (Dentsply, De Trey, Konstanz, Germany), or Ketac Endo (3M/ESPE). These groups were further divided into 2 subgroups of 16 teeth in which root ends were resected and obturated with either MTA or zinc-free amalgam. The samples have been incorporated in a dual-chamber leakage model with a polymicrobial marker of five facultative anaerobes on the coronal part. Leakage was observing during a period of 90 days. The least leakage was found in a combination of Diaket and MTA (76.9 +/-14.8 days) followed by AH Plus and MTA (66.1 +/- 18.7), Diaket and amalgam (60.0 +/- 23.1), AH Plus and amalgam (56.9 +/- 22.1), and Ketac Endo and MTA (42.1 +/- 17.8), whereas the greatest leakage was observed in the Ketac Endo and amalgam group (40.0 +/- 17.24). Samples filled with MTA showed significantly better sealing than samples filled with amalgam (p < 0.05).

Impact of aminoglycoside cycling in six tertiary intensive care units: prospective longitudinal interventional study.

AIM: To determine the effect of aminoglycoside cycling in six tertiary intensive care units (ICU) on the rates of sepsis, aminoglycoside resistance patterns, antibiotic consumption, and costs. METHODS: This was a prospective longitudinal interventional study that measured the effect of change from first-line gentamicin usage (February 2002-February 2003) to amikacin usage (February 2003-February 2004) on the aminoglycoside resistance patterns, number of patients with gram-negative bacteremia, consumption of antibiotics, and the cost of antimicrobial drugs in 6 tertiary care ICUs in Zagreb, Croatia. RESULTS: The change from first-line gentamicin to amikacin usage led to a decrease in the overall gentamicin resistance of gram-negative bacteria (GNB) from 42% to 26% (P<0.001; z-test of proportions) and netilmicin resistance from 33% to 20% (P<0.001), but amikacin resistance did not change significantly (P=0.462), except for Acinetobacter baumanni (P=0.014). Sepsis rate in ICUs was reduced from 3.6% to 2.2% (P<0.001; chi(2) test), with a decline in the number of nosocomial bloodstream infections from 55/100 patient-days to 26/100 patient-days (P=0.001, chi(2) test). Furthermore, amikacin use led to a 16% decrease in the overall antibiotic consumption and 0.1 euro/patient/d cost reduction. CONCLUSION: Exclusive use of amikacin significantly reduced the resistance of GNB isolates to gentamicin and netilmicin, the number of GNB nosocomial bacteremias, and the cost of total antibiotic usage in ICUs.