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ABSTRACT: The alarmingly increasing resistance rates among non-fermenting Gram-negative species, particularly Pseudomonas aeruginosa and Acinetobacter baumannii, intensified the interest in alternative antibiotic treatment options. Isepamicin, an old aminoglycoside, may play a role in the treatment of patients with infections caused by those multi-drug resistant pathogens. We evaluated the antimicrobial activity of isepamicin against non-fermenting Gram-negative isolates collected of the microbiological laboratory at the University Hospital of Heraklion, Crete, Greece from 2004 to the first trimester of 2011. We tested a total of 4,219 isolates (66.2 % Pseudomonas spp., 30 % Acinetobacter spp., 3.8 % other non-fermenters). The lower respiratory tract, pus, and urine were the most frequent sites of isolation (29.7 %, 19.9 %, and 12.9 %, respectively). Overall, 2768 (65.6 %) of the evaluated isolates were susceptible to isepamicin (including 79.9 % of Pseudomonas spp, 37.2 % of Acinetobacter spp, 43.1 % of other non-fermenters). Isepamicin exhibited higher antimicrobial activity compared to broad spectrum penicillins, cephalosporins, other aminoglycosides, carbapenems, and fluoroquinolones. Only colistin was more active than isepamicin. Additionally, 41.7 % of carbapenem-resistant and 53.2 % of colistin-resistant P. aeruginosa isolates were susceptible to isepamicin. The susceptibility rates for the respective types of A. baumannii isolates were 12 % and 6.2 %. Yet, isepamicin was active against 29.2 % of A. baumannii that were resistant to all other tested aminoglycosides. Isepamicin exhibits considerable antimicrobial activity against Gram-negative non-fermenters in a region with high antimicrobial resistance. Particularly, isepamicin may provide a therapeutic option for infections from carbapenem- and colistin-resistant P. aeruginosa and other aminoglycoside-resistant A. baumannii. Further modifications in the aminoglycoside molecule may provide formulations with enhanced antimicrobial activity.
European Journal of Clinical Microbiology 07/2012; 31(11):3191-8. · 2.86 Impact Factor
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ABSTRACT: In this study, we investigated the long-term trends in the epidemiology and susceptibility of bacterial enteropathogens among children in a well-defined area of adequate health standards. The study included all children younger than 14 years of age treated for enteritis at Heraklion University General Hospital on the island of Crete during the 18-year period from January 1993 to December 2010. Stool specimens were tested for Salmonella, Shigella, Campylobacter, enteropathogenic Escherichia coli (EPEC), Yersinia, and Aeromonas species. Of the 33,032 stool samples from patients of any age, 2,912 (8.82%) were positive for bacterial enteropathogens. The 1,597 isolates from children were identified as S. enterica (42.3%), Campylobacter spp. (33.6%), EPEC (17.4%), Y. enterocolitica (5.82%), A. hydrophila (0.44%), and Shigella spp. (0.38%). A decline in prevalence was observed for all bacterial enteropathogens. Taken as a total, enteropathogens were susceptible to gentamicin, ceftriaxone, ciprofloxacin, co-trimoxazole, and amoxicillin in 98.8%, 88.0%, 83.0%, 67.1%, and 59.6%, respectively. During the study period, the susceptibility rates decreased for co-trimoxazole (p<0.0001) and ciprofloxacin (p<0.001), and increased for amoxicillin (p<0.0001). Our findings suggest declining long-term trends in the prevalence of bacterial enteropathogens and changes in susceptibility rates to first-line antibacterial agents. These changing trends in the long-term morbidity and susceptibility call for ongoing surveillance and tailored management.
European Journal of Clinical Microbiology 12/2011; 31(8):1889-94. · 2.86 Impact Factor
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ABSTRACT: Pseudomonas aeruginosa is an unusual uropathogen that is mostly responsible for nosocomial or catheter associated urinary tract infections in adults. Data about P. aeruginosa urinary tract infections in children are scarce. We investigated P. aeruginosa urinary tract infections in children in a well-defined area.
Clinical, laboratory and radiological characteristics of all children with P. aeruginosa urinary tract infections were compared to those of gender matched children with community acquired Escherichia coli urinary tract infections during a 12-year period.
A total of 35 children with 43 P. aeruginosa urinary tract infection episodes representing 6.7% of total urinary tract infection cases during the study period were compared to 70 children with E. coli urinary tract infections. Children with P. aeruginosa more often presented with a history of at least 1 previous urinary tract infection episode (p <0.0001), hospitalization (p = 0.0001), use of antibiotics (p = 0.0001), malformations predisposing to urinary tract infections (p = 0.004), vesicoureteral reflux (p <0.0001), abnormal dimercapto-succinic acid scan (p = 0.0003), longer hospitalization and surgery. Use of antibiotics either as prophylaxis or as treatment within the preceding 2 months was demonstrated by multivariate logistic regression analysis as the single independent risk factor for P. aeruginosa urinary tract infections (odds ratio 21.6, 95% CI 4.65-100, p = 0.0001). P. aeruginosa isolates were often resistant to gentamicin (27.9%) and ceftazidime (13.9%) but remained sensitive to carbapenems and ciprofloxacin.
P. aeruginosa urinary tract infection is associated with distinct risk factors and outcomes, and should be considered in predisposed children with symptoms of urinary tract infection who are on prophylaxis or have a history of a recent course of antibiotics.
The Journal of urology 11/2011; 187(1):260-4. · 4.02 Impact Factor
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ABSTRACT: Fosfomycin represents a potential last-resort treatment option for infections with certain multidrug-resistant (MDR) Gram-negative pathogens. We evaluated double-drug combinations of fosfomycin with imipenem, meropenem, doripenem, colistin, netilmicin, and tigecycline for in vitro synergy against 100 MDR Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa clinical isolates, using the Etest method. Synergy was defined as a fractional inhibitory concentration index ≤ 0.5. The isolates were consecutively collected at a university hospital in Greece from various clinical specimens. Against 50 serine carbapenemase-producing K. pneumoniae isolates, synergy of fosfomycin with imipenem, meropenem, doripenem, colistin, netilmicin, and tigecycline was observed for 74.0%, 70.0%, 74.0%, 36.0%, 42.0%, and 30.0% of the isolates, respectively. Against 14 extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae isolates, synergy of fosfomycin with imipenem, meropenem, doripenem, colistin, netilmicin, and tigecycline was observed for 78.6%, 42.9%, 42.9%, 7.1%, 42.9%, and 21.4%, respectively; for 20 ESBL-producing E. coli isolates, the corresponding values were 55.0%, 25.0%, 30.0%, 15.0%, 25.0%, and 25.0%; and for 15 MDR P. aeruginosa isolates, the corresponding values were 46.7%, 53.3%, 73.3%, 13.3% , 13.3%, and 13.3%. Antagonism was not observed for any of the combinations tested. Further studies are needed in order to confirm the clinical relevance of the above findings.
European Journal of Clinical Microbiology 07/2011; 31(5):695-701. · 2.86 Impact Factor
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ABSTRACT: Infant colonization by Staphylococcus aureus has not been adequately investigated. In this study, we aimed to define determinants associated with the carriage of S. aureus in early infancy. Serial nasal swabs were collected from 128 infants and their mothers at months 0, 6, and 12 postpartum. S. aureus isolates were characterized by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), spa typing, and the presence of chromosomal mecA and of Panton-Valentine leukocidin (PVL) genes. S. aureus was isolated in 17.7% and 15.7% of swabs from infants and mothers, respectively. Carriage rates were higher in infants with carrier mothers, non-smoking mothers, and many siblings. Persistent carriage rates were higher in infants with carrier or non-smoking mothers. S. aureus typing revealed identical strains in 10/15 investigated infant-mother pairs. Among 19 investigated S. aureus isolates from infants, ten harbored mecA and two harbored PVL genes, and these determinants were concomitantly present in isolates from mothers. Resistance to methicillin was 43.6% among all isolates from infants. In conclusion, isolates from infants were commonly identical to isolates from their mothers, pointing to a principal role of maternal carriage in S. aureus colonization in infants.
European Journal of Clinical Microbiology 03/2011; 30(9):1111-7. · 2.86 Impact Factor
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ABSTRACT: We aimed to present our experience regarding infections caused by Serratia spp. in a region with relatively high antimicrobial resistance rates. We retrospectively reviewed the databases of the microbiological laboratory of the University Hospital of Heraklion, Crete (2/2004-12/2009). A total of 77 patients [67.5% men, mean age ± standard deviation (SD) = 56.9 ± 24.5 years) were identified; 37.7% were outpatients. Sixty-five (84.4%) of the 77 included patients had a Serratia marcescens isolate; the remaining 12 patients had a non-marcescens Serratia spp. The most frequently observed infections were respiratory tract infection (32.5%) and keratitis/endophthalmitis (20.8%). Seventy-three (94.9%) patients were cured. Four deaths were observed; three of them were considered as attributed to the Serratia infection. No difference was found regarding the characteristics and outcomes between patients with Serratia marcescens and non-marcescens infections. In addition, antipseudomonal penicillins and their combinations with beta-lactamase inhibitors, as well as carbapenemes, and fluoroquinolones exhibited high antimicrobial activity against both the tested Serratia marcescens and non-marcescens isolates. Our study adds useful information regarding the characteristics and outcomes of patients with Serratia infection, as well as the susceptibilities of the respective Serratia marcescens and non-marcescens isolates, in a region with relatively high levels of antimicrobial resistance.
European Journal of Clinical Microbiology 01/2011; 30(5):653-60. · 2.86 Impact Factor
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ABSTRACT: Saccharomyces boulardii has been and continues to be extensively used as a probiotic, with only rare associations with fungemia. This study evaluated the virulence of this yeast when given as a probiotic, and its role in preventing gastrointestinal (GI) colonization by Candida. Adult male Crl:CD1 (ICR) BR mice were given S. boulardii orally in three different doses or normal saline for 14 days. Stool cultures were performed at the time of discontinuation of yeast administration, as well as 1 and 2 weeks later. Gut colonization was proportional to the given dose but lasted only 1 week and no dissemination of the yeast was detected. S. boulardii was also given for 2 and 4 weeks to mice fed chow containing Candida albicans. S. boulardii in the gut did not affect Candida GI colonization. These findings suggest that oral administration of S. boulardii induces a substantial but short term increase of this yeast in the intestinal lumen and administration of the probiotic does not prevent subsequent GI colonization by C. albicans.
Medical mycology: official publication of the International Society for Human and Animal Mycology 11/2010; 49(4):395-9. · 2.13 Impact Factor
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ABSTRACT: Due to its increased non-susceptibility rates, Klebsiella pneumoniae has emerged as one of the most problematic pathogens.
The level of resistance to 25 antimicrobials of K. pneumoniae isolates from a teaching hospital in Greece and the evolution trends during 2 decades were examined.
A statistically significant increase in non-susceptibility rates was found for almost all antimicrobials examined. During 2008, the isolates presented non-susceptibility rates to aminoglycosides >50% and to quinolones >60%. Nowadays, 1 out of 10 isolates is non-susceptible to colistin. Moreover, the isolates non-susceptible to imipenem were almost doubled between 2007 (29%) and 2008 (50%). Among the imipenem-resistant isolates, 1 out of 4 was also resistant to colistin.
The effectiveness of carbapenems has been compromised and the increase in resistance to colistin is rapid and steep.
Chemotherapy 11/2010; 56(6):448-52. · 1.82 Impact Factor
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ABSTRACT: All Streptococcus pneumoniae strains isolated from paediatric clinical samples at Heraklion University General Hospital in the 10-year period 2000-2009 were tested for serotype and susceptibility to antimicrobials. Among a total of 258 strains, 159 were isolated in the 5-year period 2000-2004, before the introduction of the heptavalent pneumococcal conjugate vaccine (PCV7), and 99 in the post-PCV7 5-year period 2005-2009. The prevalence of PCV7-included serotypes decreased in the post-PCV7 period (p = 0.0002), but an increase was observed for serotypes 7F (p = 0.002) and 19A (p = 0.004). Pan-susceptibility rates and susceptibility to cotrimoxazole increased in the post-PCV7 period (p = 0.01 and p = 0.008, respectively), but serotype 19A emerged as a contributor to multi-resistance (p = 0.007). PCV7 was followed by decreased S. pneumoniae resistance and prevalence of vaccine-related serotypes but increased prevalence of serotypes 7F and 19A. Continuing surveillance is required after the recent introduction of PCV10 and PCV13.
European Journal of Clinical Microbiology 11/2010; 29(11):1449-51. · 2.86 Impact Factor
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ABSTRACT: Fluoroquinolones are broad-spectrum antibiotics increasingly utilized as empirical or prophylactic therapy in the management of cancer patients. We evaluated the effects of newer generation fluoroquinolones on the level of gastrointestinal (GI) colonization by Candida albicans in a previously established mouse model. Adult male Crl:CD1 (ICR) BR mice were fed chow containing Candida albicans or regular chow. The mice fed the Candida chow had their gut colonized by the yeast. Both groups were subsequently given levofloxacin, moxifloxacin, prulifloxacin or normal saline for 10 days. Stool cultures were performed immediately before, at the end, and one week after discontinuation of treatment to determine the level of intestinal yeast colonization. Candida-colonized mice treated with fluoroquinolones had substantially higher yeast counts in their stools than control mice fed Candida containing chow but treated with saline. Mice fed regular chow and treated with the study antibiotics or saline did not have any Candida in their stools. Dissemination of Candida to internal organs was not observed in any animal. In conclusion, we have shown that all fluoroquinolones tested induced substantial increases in the murine intestinal concentration of C. albicans.
Medical mycology: official publication of the International Society for Human and Animal Mycology 11/2010; 49(4):419-23. · 2.13 Impact Factor
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ABSTRACT: Clinical reports on infections by pandrug-resistant (PDR) bacteria are scarce. This observational case series study was conducted during a 2-year period at a university hospital. Patients infected by PDR gram-negative bacteria comprised the study cohort. An isolate was defined as PDR if it was resistant to all antibiotic classes available for empirical treatment. A total of 21 patients infected by PDR gram-negative bacteria were recorded. The mean APACHE II score on admission was 18.8, the mean Charlson comorbidity index was 2.9, and 20 (95.2%) patients had a history of intensive care unit hospitalization. All patients had recent exposure to multiple antibiotics (median, 6 antibiotic groups). Infections occurred at a mean of 41.5 days after admission. The mean length of stay after infection was 54.6 days and 5 (23.8%) patients died due to the infection. Treatment was mainly based on a colistin-containing regimen (47.6%) or tigecycline (33.3%). All patients treated with tigecycline had total resolution of the infection and a notably shorter length of hospital stay after infection. In conclusion, PDR gram-negative bacterial infections are associated with considerable prolongation of hospitalization and mortality, although the mortality is not as high as that expected. Tigecycline appears to be effective for the successful treatment of PDR infections
European Journal of Clinical Microbiology 03/2010; 29(3):301-5. · 2.86 Impact Factor
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ABSTRACT: We report on the serotype distribution and the antimicrobial susceptibility patterns (ASP) to 19 antibiotics of 195 Streptococcus pneumoniae isolates (41 invasive) collected over the period 2001-2008 from adult patients.
Pneumococcal isolates were serotyped by the Quellung reaction, and ASP testing was performed using E-test.
Isolates with intermediate and high-level resistance to penicillin increased from 17 and 12.4% over the period 2001-2004 to 31.1 and 16.7% over the years 2005-2008, respectively (p = 0.03). Macrolide resistance increased from 27.6 to 38.9%, but this was not significant (p = 0.13), while resistance to trimethoprim-sulfamethoxazole did not change over time, with approximately one fourth of the isolates being resistant. Only one isolate was resistant to fluoroquinolones. Multi-resistance was observed among 42 (58.1%) penicillin non-susceptible strains. The isolates tested belonged to 20 different serotypes. Serotypes 19F and 19A were the most common among penicillin-resistant isolates. The currently licensed 23-valent pneumococcal polysaccharide vaccine covered 98.4% of all 186 typeable S. pneumoniae strains.
Our study emphasizes the importance of continued serotyping and surveillance of antimicrobial susceptibility of all S. pneumoniae clinical isolates, especially invasive ones, in order to guide the clinician in the choice of appropriate empirical antibiotic therapy for serious pneumococcal infections.
Chemotherapy 01/2010; 56(4):325-32. · 1.82 Impact Factor
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ABSTRACT: To report the epidemiologic, bacteriologic, and clinical features of a Chryseobacterium meningosepticum outbreak in a neonatal intensive care unit (NICU) of a referral teaching hospital.
From April to October 2002, a strain of C. meningosepticum was isolated from four neonates in the NICU. All neonates were colonized in the endotracheal tubes and respiratory secretions, but none of them progressed to clinical infection. Multiple samples were obtained for cultures.
Pulsed-field gel electrophoresis (PFGE) of isolates showed them to be representatives of a single strain. Environmental surveillance did not reveal the C. meningosepticum source. None of the neonates received specific treatment. The outbreak was only controlled by reinforcement of the usual measures and no additional colonization/infection was confirmed for more than a year after the last case.
This study suggests that C. meningosepticum colonization in neonates does not necessarily lead to infection and that such colonization outbreaks may be controlled with emphasis on the standard precautions.
European Journal of Clinical Microbiology 09/2009; 28(12):1415-9. · 2.86 Impact Factor
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Journal of chemotherapy (Florence, Italy) 05/2009; 21(2):222-5. · 1.08 Impact Factor
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ABSTRACT: Haemophilus influenzae is an important human pathogen.
The purpose of the present retrospective study is to describe the antibiotic susceptibility to several common antibiotics of 930 consecutive clinical isolates of H. influenzae over the period of 1996-2005 in a tertiary general hospital on the island of Crete, Greece.
Overall, 9.5% of the isolates were beta-lactamase producing. Resistance to ampicillin and amoxicillin-clavulanate was observed in 11 and 0.6% of the strains, respectively, remaining stable throughout the study period. Resistance to tetracycline increased from 1.6% in 1996 to 38% in 2005, while resistance to ciprofloxacin and ofloxacin was <1%. A significant decrease in resistance to trimethoprim-sulfamethoxazole was observed during the study period. No significant changes in resistance to other antimicrobials were seen.
Amoxicillin-clavulanate and older quinolones remain potent agents against H. influenzae. Constant surveillance ofantibiotic susceptibility of H. influenzae clinical isolates is important in order to guide appropriate empirical antibiotic therapy.
Chemotherapy 10/2008; 54(6):492-8. · 1.82 Impact Factor
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ABSTRACT: In this investigation, we sought to investigate the characteristics of Citrobacter spp. infections. A retrospective cohort study in a 700-bed, tertiary care, university hospital was carried out during the period from June 1994 to January 2006. Seventy-eight patients (70 adults) with Citrobacter spp. isolates were identified. C. freundii was more common (71.8%), followed by C. koseri (23.1%) and C. braakii (3.8%). The most common associated clinical syndromes were urinary tract infections (52.6% of cases, including eight cases of asymptomatic bacteriuria), as well as intra-abdominal (14.1%), surgical site (7.7%), skin and soft tissue (6.4%), and respiratory tract infections (6.4%). In 29.5% of patients, Citrobacter spp. isolates were associated to polymicrobial infections, principally at sites other than the urinary tract. Antibiograms of 38 consecutive Citrobacter spp. isolates (29 C. freundii) were available. Most active agents were colistin (100%), fosfomycin (100%), imipenem (97.4%), gentamicin (89.5%), nitrofurantoin (89.5%), ciprofloxacin (80.6%), and cefepime (73.7%). Most patients (82.1%) had at least one underlying illness. Combination antimicrobial therapy was administered in 28.2% of cases. One patient died during hospitalization. The length of hospital stay was longer in patients with polymicrobial compared to monomicrobial infections (23 versus 13 days, respectively, p = 0.02). The isolation of Citrobacter species, although rather infrequent, was clinically relevant in the great majority of cases. Further attention should be paid to these pathogens.
European Journal of Clinical Microbiology 09/2008; 28(1):61-8. · 2.86 Impact Factor
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European Journal of Clinical Microbiology 09/2007; 26(8):607-9. · 2.86 Impact Factor
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A Gikas,
E I Kritsotakis, S Maraki,
M Roumbelaki,
D Babalis,
E Scoulica,
C Panoulis,
E Saloustros,
E Kontopodis,
G Samonis,
Y Tselentis
Journal of Hospital Infection 07/2007; 66(2):194-6. · 3.39 Impact Factor
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European Journal of Clinical Microbiology 03/2007; 26(2):151-2. · 2.86 Impact Factor
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ABSTRACT: Morganella morganii is a commensal Gram-negative bacillus of the intestinal tract of humans and other mammals and reptiles. Few reports exist in the literature regarding infections caused by this organism.
A retrospective study at the 650-bed University Hospital of Heraklion, Crete, Greece was performed during a 4-year period (2001-2004) to identify and analyze infections caused by M. morganii.
Twenty-four patients had M. morganii isolated from clinical specimens during the study period. Thirteen patients (54%) suffered from skin and soft tissue infections, five from pyelonephritis, three from female genital tract infections, one from pneumonia, one from gangrenous appendicitis, and one from tonsillitis. M. morganii was a constituent of polymicrobial infections in 14 patients (58%). The patients received various antibiotics, i.e., six patients received ciprofloxacin, four piperacillin/tazobactam, two amoxicillin/clavulanic acid, one ticarcillin/clavulanic acid, one ceftriaxone, one imipenem, and one cefuroxime monotherapy, whereas the remaining eight received antibiotic combinations. Two (both debilitated) of 24 patients (8%) died, despite antibiotic treatment.
Skin and soft tissue infection was the commonest type of infection due to M. morganii in our series. M. morganii is commonly a part of polymicrobial infections and can rarely cause fatalities in debilitated patients.
Infection 01/2007; 34(6):315-21. · 2.66 Impact Factor
