Prognostic factors for nosocomial bacteraemia outcome: a prospective study in a Greek teaching hospital.

Epidemiological and clinical features were studied as potential prognostic factors for outcomes of bacteraemic patients in a tertiary care teaching hospital in Greece. The prospective study was conducted over 12 months and enrolled 153 consecutive hospital-acquired bacteraemic episodes in 137 patients. The crude in-hospital mortality rate was 27% (37/137). The mean lengths of stay and of antimicrobial treatment were significantly longer for patients with a fatal outcome than for survivors (P<0.0001 and P=0.001, respectively). Needs for mechanical ventilation, urinary catheters and parenteral nutrition before or during the onset of episodes were significantly associated with fatalities [odds ratio (OR)=5.54, 95% confidence intervals (CI) 2.22-14.0, P<0.0001; OR=0.70, 95% CI 0.63-0.79, P=0.021; OR=5.03, 95% CI 1.88-13.95, P<0.0001, respectively]. Also, in logistic regression analysis, mechanical ventilation (OR=5.5, 95% CI 1.2-7.9, P=0.02) and parenteral nutrition (OR=8.8, 95% CI 3.8-11.4, P=0.003) were independent predictors of mortality. No differences between fatalities and survivors were found in sex, age, smoking habit, intensive care unit hospitalization, need for a nasogastric catheter and previous surgery. Neutropenia was associated with a fatal outcome (OR=3.65, 95% CI 1.24-10.91, P=0.006). None of the bacterial pathogens were significantly associated with an adverse outcome, whereas Staphylococcus aureus was recovered more frequently from survivors (P=0.02). Fatalities were more often associated with an intravascular catheter origin (P=0.002), whereas bacteraemias in survivors were associated with a skin/soft tissue origin (P=0.02). Various prognostic factors were associated with outcome in our bacteraemic population, and can be employed to identify bacteraemic patients at risk of death and to develop local strategies for its prevention.

Increasing prevalence of high-level gentamicin resistance among Enterococci isolated in Greece.

High-level gentamicin-resistant enterococci (HLGRE) (MIC >512 microg/ml) were frequently recovered in the AHEPA University Hospital, Thessaloniki, Greece, during a 15-month period (67/158, 42.4%). PCR testing showed that high-level gentamicin resistance was attributable to the presence of the aac(6')-aph(2") gene, while the recently described genes aph (2")-Ic and aph(2")-Id were not detected. High-level gentamicin resistance could be transferred with varying frequency from 41 of 57 Enterococcus faecalis and 5 of 10 Enterococcus faecium isolates. All transconjugants acquired high-level resistance to streptomycin. HLGRE cause therapeutic problems in our region, since none of the clinically available aminoglycosides can be used in severe infections.

Genetic relatedness of group A streptococci of the newly designated serotype M90 causing a food-borne outbreak and sporadic infections.

Twenty-six isolates of the newly designated M90 serotype group A Streptococcus (GAS) from a large food-borne outbreak of pharyngitis in Greece and six M90 sporadic isolates from UK, were typed by pulsed-field gel electrophoresis (PFGE). Twenty-four outbreak isolates were identical and two closely related. The Greek isolates were possibly related with one UK isolate, while other sporadic isolates exhibited distinct PFGE profiles from the former isolates.

Pheromone responses and high-level aminoglycoside resistance of conjugative plasmids of Enterococcus faecalis from Greece.

Fifteen of 22 clinical isolates of Enterococcus faecalis with high-level aminoglycoside resistance isolated in Greece, which were tested for mating ability, co-transferred pheromone response genes together with aminoglycoside resistance determinants to a sensitive recipient strain. Nine of them belonged to the same pulsotype, while the remaining six isolates were genetically unrelated. The prgB gene, which encodes aggregation substance, was detected in all the clinical isolates and transconjugants by both PCR and DNA hybridization but prgA, which encodes the surface exclusion protein, was only detected in two isolates, whereas it is present in most pheromone response plasmids from other sources.

Outbreak of infections caused by Pseudomonas aeruginosa producing VIM-1 carbapenemase in Greece.

Resistance to imipenem and meropenem was observed in 211 (16.5%) isolates of Pseudomonas aeruginosa recovered in a Greek university hospital during 1996 to 1998. In six isolates selected from throughout this period, high-level resistance to both carbapenems (MICs >/= 128 microg/ml) was associated with production of the class B beta-lactamase VIM-1. bla(VIM)-bearing isolates belonged to serotype O:12 and were indistinguishable by pulsed-field gel electrophoresis.

Outbreak of infections in a Greek university hospital involving a single clone of high-level aminoglycoside-resistant Enterococcus faecalis.

Among 145 Enterococcus faecalis isolates recovered during a 15-month period (April 1997-June 1998) in AHEPA University Hospital, Thessaloniki, Greece, 94 (65%) exhibited high-level resistance to gentamicin or streptomycin and 61 (42%) to both aminoglycosides; 73% of the high-level aminoglycoside-resistant E. faecalis isolates belonged to a single clone carrying the gene aac(6')-Ie-aph(2")-Ia. These findings differ from those of other regions, where high-level aminoglycoside-resistance genes are dispersed into genetically unrelated strains.

Study on the use of an enzyme-linked immunosorbent assay in determining human antibodies to diphtheria toxin as compared with a reference toxin neutralization assay.

Serum samples from 156 Greek persons were assessed by an IgG-specific enzyme-linked immunosorbent assay (ELISA) and a reference tissue culture toxin-neutralization (TN) assay for the quantitation of diphtheria toxin antibodies. By the reference method, 7.7% of the persons were susceptible to diphtheria (antitoxin < 0.01 IU/ml), 28.8% had basic protection (antitoxin 0.01-0.09 IU/ml) and 63.5% were fully protective (antitoxin > or = 0.1 IU/ ml), while the corresponding figures were 17.9, 36.5 and 45.5% when they were tested by the immunoassay. None of the samples been susceptible by the TN assay were found to have some protection when tested by ELISA. However, three (6.7%) of the 45 samples showing a basic protection with TN, were fully protective when titrated by the immunoassay. In addition, 31 (31.3%) of the 99 samples been fully protective by the bioassay, were found to be either basically protective or susceptible by means of the ELISA. Overall, validity features of the immunoassay were: sensitivity 68.7%, specificity 94.7%, positive predictive value 95.8% and negative predictive value 63.5%. The ELISA tested in our study could be used to determine diphtheria antitoxin in individuals needed a booster immunization (susceptible or basic protective samples), although it might falsely include in the above categories samples that are within the fully protective levels of antibodies.

Diphtheria immunity of Albanian and other eastern European immigrants in Greece compared with the local population--the risk of reemergence in Greece.

A large number of immigrants have come to Greece from diphtheria-endemic countries during the past 8 years. Information on the immune status against diphtheria among immigrants from Albania and the New Independent States (NIS) of the former USSR, as well as the Greek population, is essential in planning public health control measures. The main objective of the study was to determine the risk of the spread of diphtheria if new cases arrived in the country. Diphtheria antitoxin (DAT) in sera from 185 healthy individuals from northern Greece and 227 immigrants from Albania and the NIS was titrated using a quantitative ELISA test. The participants were adults aged 22 to 46 years. Titers were considered as protective when DAT levels were higher or equal to 0.1 IU/ml. Albanian immigrants exhibited the highest rates of protective titers (99 of 167, 59.3%), while lower immunity rates were detected among immigrants from the NIS (20 of 60, 33.3%) (1.5 < OR = 2.9 < 5.4, p = 0.0007) as well as among Greek participants (47 of 185, 25.4%) (2.8 < OR = 4.4 < 7.0, p = 0.00001). Immunity rates did not differ between Greek and NIS participants. DAT levels of persons with protective titers differed between the three population groups (analysis of variance, p = 0.0005), with the highest mean DAT values detected among NIS immigrants (0.613 IU/ml). Lower values were found among protected Albanians (0.482 IU/ml) and Greeks (0.314 IU/ml). There was no significant age- and sex-related difference in immunity rates and DAT levels among the groups. The low immunity rates among Greek adults might suggest that they have had no natural contact with toxigenic strains of corynebacteria. A booster dose of diphtheria toxoid for local adults is recommended, to reduce their risk of acquiring toxigenic strains from individuals who may carry the bacteria without exhibiting clinical disease.

Reported needlestick and sharp injuries among health care workers in a Greek general hospital.

Between July 1990 and June 1996, 284 exposures to infectious material were reported by 247 health care workers (HCWs) at AHEPA University Hospital, Thessaloniki, Greece, representing an overall rate of 2.4% reported injuries per 100 HCWs/year. Nurses reported the highest rates of incidents (3.0%) and in all but one working group women exhibited higher injury rates per year than male HCWs. Young workers (21-30 years old) were primarily affected in incidents (P < 0.001). Needles were the most common implement causing injury (60.6%) and resheathing of used needles as well as garbage collection were common causes of injury. None of the HCWs seroconverted in exposures where immune status to blood-borne pathogens was estimated. Efforts by the infection control committee need to be more intense, in order to increase the rate of reported staff injuries. This will facilitate identification of unsafe practices and provide more adequate preventive measures.

Apparent increased prevalence of high-level aminoglycoside-resistant Enterococcus durans resulting from false identification by a semiautomated software system.

Identification of enterococci by using a semiautomated system (PASCO; Difco Laboratories, Detroit, Mich.) in the AHEPA University Hospital, Thessaloniki, Greece, revealed a high proportion of Enterococcus durans, particularly among isolates highly resistant to gentamicin and streptomycin. When 14 isolates were further tested by a conventional biochemical scheme and by PCR, all were reidentified as Enterococcus faecalis. Antibiotic resistance and pulsed-field gel electrophoresis patterns showed that unrelated strains were misidentified.

High rates of resistance to piperacillin/tazobactam among Escherichia coli and Klebsiella pneumoniae strains isolated in a Greek hospital.

The activities of piperacillin/tazobactam (PTZ) and 10 other beta-lactams were evaluated by a broth microdilution method using the PASCO system in 1078 Escherichia coli and 447 Klebsiella pneumoniae strains isolated from hospitalized patients in a Greek hospital. Overall, 10.5% of the former and 62.6% of the latter strains displayed resistance to PTZ. Most of the PTZ-resistant strains (71.2%) expressed extended spectrum beta-lactamases and were also resistant to broad spectrum cephalosporins and aztreonam. The high rates of PTZ resistance in E. coli and K. pneumoniae and the extensive cross-resistance to other beta-lactams suggest that PTZ should be used with caution in our clinical setting.

Diversity of beta-lactamases among Klebsiella pneumoniae strains isolated in a university hospital in Greece.

Among 48 clinical strains of Klebsiella pneumoniae isolated in a university hospital in Northern Greece, 29 (60.4%) exhibited resistance to third generation cephalosporins (3GC) and aztreonam. Thirty-two (66.7%) of the isolates were found resistant to the combination of ampicillin/sulbactam and six (12.5%) exhibited resistance to all the above antibodies plus cefoxitin. Resistance to 3GC was related mostly with the presence of a beta-lactamase exhibiting pI 8.2 and substrate profile of an SHV-5 type enzyme and rarely (in two of the cefoxitin resistant strains) with the presence of plasmid-mediated class C cephalosporinases. Resistance to the ampicillin/sulbactam combination was associated with the presence of a beta-lactamase with pI 5.4, presumably representing a TEM-1 beta-lactamase. These findings record a diversity of beta-lactamases and explain, at least partly, the various beta-lactam resistance patterns observed in our K. pneumoniae sample.

Multidrug resistance among methicillin-resistant Staphylococcus aureus in Greece.

A total of 472 strains of Staphylococcus aureus isolated in a university hospital in Thessaloniki, Greece during 1993-1994 were studied; 202 (42.8%) of them were characterized as methicillin-resistant (MRSA) and were mainly recovered from respiratory materials. The minimal inhibitory concentrations (MICs) of methicillin-susceptible (MSSA) and methicillin-resistant strains to 10 alternative antibiotics were also compared. All MRSA isolates were resistant to penicillin and most of them, in contrast to MSSA, exhibited resistance to gentamicin, tobramycin, tetracycline, erythromycin and ciprofloxacin with resistance rates ranging from 89.6% to 59.4%. Also, considerable proportions of MRSA were found resistant to co-trimoxazole (47.0%) and rifampicin (27.7%). All isolates were sensitive to vancomycin while susceptibility to chloramphenicol was of equal incidence among the examined populations. Overall, MRSA vs. MSSA exhibited a significantly (chi 2; P < 10-8) higher incidence of resistance to 8 out of the 10 antibiotics examined.

Complicated suppurative otitis media in a Greek diver due to a marine halophilic Vibrio sp.

Halophilic vibrios are distinct from non-cholera vibrios and have been recognized increasingly as potentially pathogenic bacteria in extraintestinal infections. A case of suppurative chronic otitis media in a Greek diver with Vibrio alginolyticus recovered from an ear drainage culture, is reported. The patient received appropriate antimicrobial therapy and her hearing improved significantly after a tympanoplasty type I was performed. The association of halophilic Vibrio spp. infections with prolonged seawater contact, particularly in subtropical climates, is discussed. In swimmers with extensive exposure to salt water, individual preventive measures and aetiological treatment of ear infections seems to be required in order to reduce the severity of possible Vibrio spp. ear infections.