Inoculum effect of CTX-M-15, OXA-48, and KPC-2 producing Klebsiella pneumoniae on meropenem and ceftazidime-avibactam efficacy.

The inoculum effect, characterized by diminished antibacterial activity at high bacterial inocula, is studied in the context of beta-lactam and beta-lactamase inhibitor combinations against beta-lactamase-producing Enterobacterales. The inhibition of ESBL + OXA-48 and KPC enzymes, in combination with ceftazidime, demonstrates encouraging results. In this study, 20 Klebsiella pneumoniae isolates were tested with different inocula (1-5 × 105 and 1-5 × 107 cfu/ml) using broth microdilution methods. The inoculum effect was observed in meropenem against OXA-48 + CTX-M-15- and KPC-2-producing isolates but not with ceftazidime/avibactam. Notably, meropenem exhibited inoculum effect against carbapenemase-producing strains, whereas ceftazidime-avibactam remained effective. We conclude that ceftazidime-avibactam is recommended for high-inoculum infections.

Carriage of multidrug-resistant Gram-negative bacilli: duration and risk factors.

Identification of risk factors influencing the duration of carriage of multidrug-resistant Gram-negative bacilli (MDR-GNB) may be useful for infection control. The aim of this study is to estimate the impact of several factors collected for routine hospital surveillance on the duration of carriage of selected MDR-GNB. From January 2015 to July 2021, patients with at least two clinical/surveillance samples positive for MDR-GNB different from ESBL-producing E. coli or AmpC - exclusively producing Enterobacterales were assessed. Microorganisms, age, number of admissions, clinical or rectal sample, sex, and admission service were evaluated as risk factors. Multivariate analysis was performed by a Cox proportional hazard model. A total of 1981 episodes of colonization were included. Involved microorganisms were ESBL-Klebsiella pneumoniae (KP) in 1057 cases (53.4%), other ESBL-non-E. coli Enterobacterales in 91 (4.6%), OXA-48-KP in 263 (13.3%), KPC-KP in 90 (4.5%), VIM-KP in 29 (1.5%), carbapenemase-producing non-KP Enterobacterales (CP-non-KP) in 124 (6.3%), and MDR Pseudomonas aeruginosa (MDR-PAER) in 327 (16.5%). No differences in duration of colonization were observed among ESBL-KP (median colonization time 320 days), ESBL-non-E. coli Enterobacterales (226 days), OXA48-KP (305 days), and MDR-PAER (321 days). For each group, duration of colonization was significantly longer than that of KPC-KP (median colonization time 60 days), VIM-KP (138 days), and CP-non-KP (71 days). Male sex (HR = 0.88; 95% CI 0.78-0.99), detection in Hepatology-Gastroenterology (HR = 0.71; 95% CI 0.54-0.93), clinical sample (HR = 0.61; 95% CI 0.53-0.69), and > 2 admissions after first detection (HR = 0.47; 95% CI 0.42-0.52) were independent predictors of longer carriage, whereas VIM-KP (HR = 1.61; 95% CI 1.04-2.48), KPC-KP (HR = 1.85; 95% CI 1.49-2.3), and CP-non-KP (HR = 1.92; 95% CI 1.49-2.47) were associated with shorter colonization time. Duration of colonization was significantly longer for ESBL-KP, other ESBL-non-E. coli Enterobacterales, OXA-48-KP, and MDR-PAER. For these microorganisms, prolonging surveillance up to 2.5-3 years should be considered. Male sex, clinical sample, multiple readmissions, admission service, and type of microorganism are independent predictors of the duration of carriage.

A comparative study between real-time PCR and loop-mediated isothermal amplification to detect carbapenemase and/or ESBL genes in Enterobacteriaceae directly from bronchoalveolar lavage fluid samples.

OBJECTIVES: To evaluate and compare the efficacy of real-time PCR (Xpert Carba-R) and loop-mediated isothermal amplification (Eazyplex® SuperBug CRE) for detecting carbapenemase carriage in Enterobacteriaceae directly from bronchoalveolar lavage (BAL). METHODS: Negative BAL samples were spiked with 21 well-characterized carbapenemase-producing Enterobacteriaceae strains to a final concentration of 102-104 cfu/mL. Xpert Carba-R (Cepheid, Sunnyvale, CA, USA), which detects five targets (blaKPC, blaNDM, blaVIM, blaOXA-48 and blaIMP-1), and the Eazyplex® SuperBug CRE system (Amplex-Diagnostics GmbH, Germany), which detects seven genes (blaKPC, blaNDM, blaVIM, blaOXA-48, blaOXA-181, blaCTXM-1 and blaCTXM-9), were evaluated for the detection of these genes directly from BAL samples. RESULTS: Xpert Carba-R showed 100% agreement with carbapenemase characterization by PCR and sequencing for all final bacteria concentrations. Eazyplex® SuperBug CRE showed 100%, 80% and 27% agreement with PCR and sequencing when testing 104, 103 and 102 cfu/mL, respectively. False negative results for Eazyplex® SuperBug CRE matched the highest cycle threshold values for Xpert Carba-R. Hands-on time for both assays was about 15 min, but Eazyplex® SuperBug CRE results were available within 30 min, whereas Xpert Carba-R took around 50 min. CONCLUSIONS: We here describe the successful use of two commercial diagnostic tests, Xpert Carba-R and Eazyplex® SuperBug CRE, to detect bacterial carbapenem resistance genes directly in lower respiratory tract samples. Our results could be used as proof-of-concept data for validation of these tests for this indication.

Activity of ceftazidime-avibactam against fluoroquinolone-resistant Enterobacteriaceae and Pseudomonas aeruginosa.

Ceftazidime-avibactam and comparator antibiotics were tested by the broth microdilution method against 200 Enterobacteriaceae and 25 Pseudomonas aeruginosa strains resistant to fluoroquinolones (including strains with the extended-spectrum ß-lactamase [ESBL] phenotype and ceftazidime-resistant strains) collected from our institution. The MICs and mechanisms of resistance to fluoroquinolone were also studied. Ninety-nine percent of fluoroquinolone-resistant Enterobacteriaceae strains were inhibited at a ceftazidime-avibactam MIC of ≤4 mg/liter (using the susceptible CLSI breakpoint for ceftazidime alone as a reference). Ceftazidime-avibactam was very active against ESBL Escherichia coli (MIC90 of 0.25 mg/liter), ESBL Klebsiella pneumoniae (MIC90 of 0.5 mg/liter), ceftazidime-resistant AmpC-producing species (MIC90 of 1 mg/liter), non-ESBL E. coli (MIC90 of ≤0.125 mg/liter), non-ESBL K. pneumoniae (MIC90 of 0.25 mg/liter), and ceftazidime-nonresistant AmpC-producing species (MIC90 of ≤0.5 mg/liter). Ninety-six percent of fluoroquinolone-resistant P. aeruginosa strains were inhibited at a ceftazidime-avibactam MIC of ≤8 mg/liter (using the susceptible CLSI breakpoint for ceftazidime alone as a reference), with a MIC90 of 8 mg/liter. Additionally, fluoroquinolone-resistant mutants from each species tested were obtained in vitro from two strains, one susceptible to ceftazidime and the other a ß-lactamase producer with a high MIC against ceftazidime but susceptible to ceftazidime-avibactam. Thereby, the impact of fluoroquinolone resistance on the activity of ceftazidime-avibactam could be assessed. The MIC90 values of ceftazidime-avibactam for the fluoroquinolone-resistant mutant strains of Enterobacteriaceae and P. aeruginosa were ≤4 mg/liter and ≤8 mg/liter, respectively. We conclude that the presence of fluoroquinolone resistance does not affect Enterobacteriaceae and P. aeruginosa susceptibility to ceftazidime-avibactam; that is, there is no cross-resistance.

In vitro activity of cefiderocol and other newly approved antimicrobials against multi-drug resistant Gram-negative pathogens recovered in intensive care units in Spain and Portugal.

OBJECTIVE: The antimicrobial resistance is a significant public health threat, particularly for healthcare-associated infections caused by carbapenem-resistant Gram-negative pathogens which are increasingly reported worldwide. The aim of this study was to provide data on the in vitro antimicrobial activity of cefiderocol and that of commercially available comparator antibiotics against a defined collection of recent clinical multi-drug resistant (MDR) microorganisms, including carbapenem resistant Gram-negative bacteria collected from different regions in Spain and Portugal. METHODS: A total of 477 clinical isolates of Enterobacterales, Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia were prospectively (n=265) and retrospectively (n=212) included (2016-2019). Susceptibility testing was performed using standard broad microdilution and results were interpreted using CLSI-2021 and EUCAST-2021 criteria. RESULTS: Overall, cefiderocol showed a good activity against Enterobacterales isolates, being 99.5% susceptible by CLSI and 94.5% by EUCAST criteria. It also demonstrated excellent activity against P. aeruginosa and S. maltophilia isolates, all being susceptible to this compound considering CLSI breakpoints. Regarding A. baumannii (n=64), only one isolate was resistant to cefiderocol. CONCLUSIONS: Our results are in agreement with other studies performed outside Spain and Portugal highlighting its excellent activity against MDR gram-negative bacteria. Cefiderocol is a therapeutic alternative to those available for the treatment of infections caused by these MDR bacteria.

Epidemiology and prognostic determinants of bacteraemic biliary tract infection.

OBJECTIVES: To determine the epidemiology of bacteraemia due to biliary tract infection (BTI) and to identify independent predictors of mortality. METHODS: This study was part of a bloodstream infection surveillance study that prospectively collected data on consecutive patients with bacteraemia in our institution from 1991 to 2010. BTI was the confirmed source of 1373 patients with bacteraemia, and the independent prognostic factors of 30 day mortality were determined. RESULTS: The mean age of patients with biliary sepsis was 71 years (± 14 years). The most frequent comorbidities were biliary lithiasis and solid-organ cancer [484 cases (35%) and 362 cases (26%), respectively]. The BTI was healthcare-associated in 33% of patients. Shock and mortality accounted for 209 and 126 cases, respectively (15% and 9%). The most frequent microorganisms isolated were Escherichia coli (749, 55%), Klebsiella spp. (240, 17%), Enterococcus spp. (171, 12%), Pseudomonas aeruginosa (86, 6%) and Enterobacter spp. (63, 5%). There were 47 (3%) cefotaxime-resistant (CTX-R) E. coli or Klebsiella spp. Inappropriate empirical antibiotic treatment was an independent factor associated with mortality (OR 1.4, 95% CI 1.1-1.7). Inappropriate empirical treatment was more frequent in P. aeruginosa and CTX-R Enterobacteriaceae bacteraemia. These microorganisms were significantly more common in patients with previous antibiotic therapy, solid-organ cancer or transplantation and in healthcare-associated bacteraemia. CONCLUSIONS: In patients with bacteraemic BTI, inappropriate empirical therapy was more frequent in P. aeruginosa and CTX-R Enterobacteriaceae infection and was associated with a higher mortality rate. In patients with bacteraemia due to BTI and solid-organ cancer or transplantation, healthcare-associated infection or previous antibiotic treatment, initial therapy with piperacillin/tazobactam or a carbapenem would be advisable.

A comparative study of two different methods of sample preparation for positive blood cultures for the rapid identification of bacteria using MALDI-TOF MS.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has lately been implemented as a solid technology for rapid microorganism identification in microbiology laboratories. This study compares two methods for bacterial separation from 85 positive blood culture before MALDI-TOF MS: (1) a conventional method that we used in our laboratory to prepare bacteria for susceptibility testing and (2) a new commercialized technique (Sepsityper). There were no significant differences in the identification of Gram-negative bacilli regardless of the bacterial separation method used. However, identification was greater for Gram-positive cocci when the Sepsityper method was used (84.15% vs. 100% in the identification to a genus level in staphylococci and 57.14% vs. 85.71% in the identification to a genus level of enterococci with the in-house and Sepsityper methods, respectively). Therefore, the Sepsityper method to prepare bacteria from a positive blood culture is more adequate for the further identification of Gram-positive cocci by MALDI-TOF MS.

Cefotaxime resistance and outcome of Klebsiella spp bloodstream infection.

We attempt to describe the epidemiology and outcome associated with cefotaxime-resistant (CTX-R) Klebsiella spp bacteraemia. Klebsiella spp bloodstream infection episodes prospectively collected through a blood culture surveillance programme from January 1991 to December 2008 in a single institution were analysed. A total of 910 monomicrobial episodes of Klebsiella spp bacteraemia were identified during the study period. The most important sources were from urinary tract infection, unknown sources, billiary focus and catheter related infection. There were 112 (12%) CTX-R isolates. Out of 112 isolates, 98 were CTX-R by Extended-Spectrum ß-Lactamase production. Shock on presentation and mortality were significantly more frequent in CTX-R than in CTX susceptible isolates. Inappropriate empirical therapy was received in 50 (45%) cases in the CTX-R Klebsiella spp group (13 cases of death, 26%). Predictive factors associated with CTX-R Klebsiella spp isolate were: previous ß-lactam therapy (OR = 4.16), nosocomial acquired bacteraemia (OR = 1.93), solid organ trasplantation (OR = 2.09) and shock (OR = 1.90). Independent risk factors associated with mortality in Klebsiella spp bacteraemia were: age (OR = 1.03), liver cirrhosis (OR = 2.63), ultimately or rapidly fatal prognosis of underlying disease (OR = 2.44), shock (OR = 8.60), pneumonia (OR = 4.96) or intraabdominal (OR = 3.85) source of bacteraemia and CTX-R isolate (OR = 4.63). Klebsiella spp is an important cause of bloodstream infection. CTX-R isolates have been increasing since 2000. CTX-R is an independent factor associated with mortality in Klebsiella spp bacteraemia.

Influence of empiric therapy with a beta-lactam alone or combined with an aminoglycoside on prognosis of bacteremia due to gram-negative microorganisms.

Evidence supporting the combination of aminoglycosides with beta-lactams for gram-negative bacteremia is inconclusive. We have explored the influence on survival of empirical therapy with a beta-lactam alone versus that with a beta-lactam-aminoglycoside combination by retrospectively analyzing a series of bacteremic episodes due to aerobic or facultative gram-negative microorganisms treated with single or combination therapy. The outcome variable was a 30-day mortality. Prognostic factors were selected by regression logistic analysis. A total of 4,863 episodes were assessed, of which 678 (14%) received combination therapy and 467 (10%) were fatal. Factors independently associated with mortality included age greater than 65 (odds ratio [OR], 2; 95% confidence interval [CI], 1.6 to 2.6), hospital acquisition (OR, 1.5; 95% CI, 1.2 to 1.9), a rapidly or ultimately fatal underlying disease (OR, 2.5; 95% CI, 2 to 3.2), cirrhosis (OR, 1.9; 95% CI, 1.4 to 2.6), prior corticosteroids (OR, 1.5; 95% CI, 1.1 to 2), shock on presentation (OR, 8.8; 95% CI, 7 to 11), pneumonia (OR, 2.8; 95% CI, 1.9 to 4), and inappropriate empirical therapy (OR, 1.8; 95% CI, 1.3 to 2.5). Subgroup analysis revealed that combination therapy was an independent protective factor in episodes presenting shock (OR, 0.6; 95% CI, 0.4 to 0.9) or neutropenia (OR, 0.5; 95% CI, 0.3 to 0.9). Combination therapy improved the appropriateness of empirical therapy in episodes due to extended-spectrum beta-lactamase (ESBL)- or AmpC-producing Enterobacteriaceae and Pseudomonas aeruginosa. In patients with gram-negative bacteremia, we could not find an overall association between empirical beta-lactam-aminoglycoside combination therapy and prognosis. However, a survival advantage cannot be discarded for episodes presenting shock or neutropenia, hence in these situations the use of combination therapy may still be justified. Combination therapy also should be considered for patients at risk of being infected with resistant organisms, if only to increase the appropriateness of empirical therapy.

Candida spp. bloodstream infection: influence of antifungal treatment on outcome.

OBJECTIVES: To assess the influence of new antifungal treatments on candidaemia outcome. METHODS: Candidaemia episodes prospectively collected through a blood culture surveillance programme in a single institution. The study was divided into two periods of time, 1994-2003 (A) and 2004-2008 (B), according to the introduction of echinocandin treatment. Non-conditional logistic regression methods with mortality as the dependent variable were used. RESULTS: Four hundred and thirty-three (3%) candidaemias out of 15 628 bloodstream infection episodes were analysed. Candida albicans was the most frequent species (211; 49%). Mortality was noted in 132 cases (30%). A total of 262 and 171 candidaemias were reported in period A and B, respectively. There were 94 deaths in period A (36%) and 38 in period B (22%, P = 0.03). Treatment in period A was amphotericin B in 89 patients (41 dead, 46%) and fluconazole in 151 (41 dead, 27%, P = 0.003). In period B, 113 patients received a triazole (26 dead, 23%), 30 an echinocandin (3 dead, 10%, P = 0.08) and 9 (0 dead) were treated with combined therapy (echinocandin and triazole). Mortality was higher in period A (94 dead, 36%) than in period B (38 dead, 27%), P = 0.03. Independent risk factors associated with mortality in period B were: age, chronic renal failure, ultimately or rapidly fatal prognosis of underlying disease and shock. Echinocandin alone or in combination therapy was associated with better outcome (odds ratio = 0.22, 95% confidence interval = 0.06-0.81, P = 0.02). CONCLUSIONS: In patients with candidaemia, echinocandin therapy results in a better outcome.

Antibiotic resistance in orthopaedic surgery: acute knee prosthetic joint infections due to extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae.

The aim of this study was to describe the prevalence and characteristics of knee prosthetic joint infections due to extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae. From 2000 to 2007, 132 infections out of 5,076 arthroplasties (2.6%) were registered. Seven out of 132 infections (5.3%) were due to ESBL-producing Enterobacteriaceae, Escherichia coli in six cases and Klebsiella pneumoniae in one. Open debridement and retention of the implant was the first surgical approach and all patients received intravenous carbapenems. Relapse was documented in four cases and remission in three. Therefore, debridement without prosthesis removal was associated with a high failure rate.

Performance of differential time to positivity as a routine diagnostic test for catheter-related bloodstream infections: a single-centre experience.

OBJECTIVE: To assess the performance of differential time to positivity (DTP) for the diagnosis of catheter-related bloodstream infections (CRBSI). METHODS: From all episodes of bloodstream infections (BSI) diagnosed during a 15-year period (2003-17) those in which a paired set of blood cultures drawn from a catheter and a peripheral vein were positive for the same microorganism and had a clinically and/or microbiologically defined source were selected. To assess diagnostic discrimination ability and accuracy of DTP for CRBSI, area under the receiver operating characteristic curves (AUC) and performance characteristics of a DTP ≥2 h were computed. RESULTS: A total of 512 BSI were included, of which 302 (59%) were CRBSI. Discrimination ability of DTP was low for Staphylococcus aureus (AUC 0.656 ± 0.06), coagulase-negative staphylococci (AUC 0.618 ± 0.081), enterococci (AUC 0.554 ± 0.117) and non-AmpC-producing Enterobacteriaceae (AUC 0.653 ± 0.053); moderate for Pseudomonas aeruginosa (AUC 0.841 ± 0.073), and high for AmpC-producing Enterobacteriaceae (AUC 0.944 ± 0.039). For the entire sample, DTP had a low-to-moderate discrimination ability (AUC 0.698 ± 0.024). A DTP ≥2 h has a low sensitivity for coagulase-negative staphylococci (60%) and very low for S. aureus (34%), enterococci (40%) and non-AmpC-producing Enterobacteriaceae (42%). A DTP cut-off of 1 h improved sensitivity (90%) for AmpC-producing Enterobacteriaceae. CONCLUSIONS: Differential time to positivity performs well for diagnosing CRBSI only when AmpC-producing Enterobacteriaceae and P. aeruginosa are involved. Performance is low for common Gram-positive organisms and non-AmpC-producing enteric bacilli; a negative test should not be used to rule out CRBSI due to these microorganisms. A DTP ≥1 h may improve accuracy for AmpC-producing Enterobacteriaceae, particularly Enterobacter spp.

[Surveillance of commensal flora evolution and infections in neutropenic cancer patients submitted to chemoprophylaxis]. / Vigilancia de la evolución de la flora comensal y de las infecciones en pacientes oncológicos con neutropenia sometidos a quimioprofilaxis.

The evolution of the flora and its resistance to different antimicrobials in neutropenic patients submitted to high-dose chemotherapy with autologous blood stem-cell transplantation, and the relation of these findings to the etiology of the infections the patients developed was studied in order to evaluate the suitability of the chemoprophylaxis and the empirical antibiotic therapy used. Forty-one patients were analyzed in a period of 28 months. The chemoprophylaxis used was levofloxacin, fluconazole and acyclovir. The empirical sequential treatment was an initial administration of cefepime, followed by teicoplanin and amikacin. Cultures were done of nasal and pharyngeal smears, Hickman catheter and stools, 1 day before chemoprophylaxis started and then on days 5 and 9. In the case of fever, three sets of blood cultures and urine cultures were done and samples from areas related to the clinical condition were analyzed. Levofloxacin induced the selection of resistant strains or species in the flora and in the infectious agents. Fluconazole also selected resistant species in the flora. Seventeen infections were documented in eleven patients, produced by Gram-positive bacteria in thirteen cases (81.25%) and by Gram-negative bacteria in three (18.75%). The coagulase negative staphylococci and Enterococcus faecalis were the most frequent agents of infection. We identified on nine occasions the same microorganism in the flora and in the pathological product; this suggests its endogenous origin and supports the use of prospective cultures of the flora, monitoring the sensibility of the microorganisms isolated to the antimicrobials used in chemoprophylaxis and empirical treatment.

Extended spectrum ß-lactamase-producing Escherichia coli faecal carriage in Spanish travellers returning from tropical and subtropical countries.

The aim of this study was to investigate the prevalence of extended-spectrum ß-lactamase (ESBL) -producing Escherichia coli in stool samples from 457 patients with travellers' diarrhoea who had travelled to tropical and subtropical countries. Ninety-seven ESBL-producing E. coli strains were isolated from 17.9% of the patients (82/457). CTX-M-15 was the most prevalent enzyme (80%) and India was the most visited country and showed the highest prevalence of positive samples (37.4%).

Epidemiology and prognostic determinants of bacteraemic catheter-acquired urinary tract infection in a single institution from 1991 to 2010.

OBJECTIVES: To determine the epidemiology of bacteraemic Catheter-Acquired Urinary Tract Infection (CA-UTI) and to identify independent predictors of mortality. METHODS: This study was part of a bloodstream infection surveillance study that prospectively collected data on consecutive patients with bacteraemia in our institution from 1991 to 2010. Factors associated with 30-day mortality were determined. RESULTS: CA-UTI was the confirmed source of 1007 bacteraemias. The most common microorganisms isolated were Escherichiacoli (42%), Klebsiella spp (15%), Enterococcus faecalis (12%) and Pseudomonas aeruginosa (12%). Along the 2006-2010 periods, antibiotic-resistant E. coli and Klebsiella spp isolates accounted for 49% of the bacteraemia due to CA-UTI. Shock and mortality accounted for 125 and 92 cases, respectively (12% and 9%). Factors associated with mortality were: inappropriate empirical treatment (OR: 1.86, 95% CI: 1.48-2.44), ultimately or rapidly fatal prognosis of underlying disease (OR: 2.56, 95% CI: 1.48-4.44) and shock on presentation (OR: 12.62, 95% CI: 7.61-20.95). Inappropriate empirical treatment was most frequent in cases of bacteraemia produced by antibiotic-resistant E. coli or Klebsiella spp, Enterococcus spp. and P. aeruginosa. Factors associated with the isolation of a microorganism of this type were previous antibiotic therapy and healthcare-associated bacteraemia (OR: 1.50, 95% CI: 1.16-2.14 and OR: 3.03, 95% CI: 2.22-4.01, respectively). CONCLUSIONS: In cases of previous antibiotic therapy or healthcare-associated bacteraemic CA-UTI may indicate the need to initiate empirical therapy activity against antibiotic-resistant Enterobacteriaceae, E. faecalis and P. aeruginosa.

Candida species bloodstream infection: epidemiology and outcome in a single institution from 1991 to 2008.

Candidaemia remains a major cause of morbidity and mortality in the healthcare setting. Candida spp. bloodstream infection episodes prospectively recorded through a blood culture surveillance programme in a single institution from 1991 to 2008 were included in the study. Data regarding candidaemia episodes were analysed, including specific fungal species and patient survival at 30 days after diagnosis. There were 529 candidaemia episodes during the study period (495 were nosocomial infections). The incidence of candidaemia caused by non-Candida albicans Candida spp. (52%) was higher than the incidence of candidaemia caused by C. albicans (48%). The overall crude 30 day mortality rate was 32%. Patients with Candida parapsilosis candidaemia had the lowest mortality rate (23%). Candida krusei candidaemia was most commonly associated with haematological malignancy (61%; P < 0.001), stem cell transplantation (22%; P = 0.004), neutropenia (57%; P = 0.001) and prior use of antifungal azole agents (26%; P < 0.001). Patients with C. krusei candidaemia had the highest crude 30 day mortality in this series (39%). Epidemiological studies are important to define clinical and microbiological candidaemia characteristics and to guide empirical treatment in every setting.

[Epidemiology and clinical presentation of Panton-Valentin leukocidin positive methicillin-resistant Staphylococcus aureus]. / Epidemiología y forma de presentación clínica de las infecciones originadas por Staphylococcus aureus resistente a meticilina productor de leucocidina de Panton-Valentine.

INTRODUCTION: the aim of our study was to review the epidemiology and clinical manifestations of infections due to Panton-Valentine leukocidin-positive methicillin-resistant Staphylococcus aureus (PVL-MRSA). MATERIAL AND METHODS: Medical history of patients infected by MRSA-PVL admitted to our hospital from January 2007 to July 2009 was reviewed. PVL and the type of cromosomic cassette were determined in all strains by PCR. RESULTS: A total of 37 cases were included. Seventy percent were males and the median age was 39 years. Sixtytwo percent were Spanish, 14 (37.8%) were HIV-positive and 11 (29.7%) were homosexual. The source of the infection was the skin and soft tissue in 36 cases and pneumonia in 1. Sixteen patients were hospitalized, 5 had bacteremia and 5 developed septic metastasis. The relapse rate was 24% (9 cases). The prevalence during the study period was 11.2% of all MRSA isolated (37 out of 329). All the strains had a cromosomic cassette type IV and were susceptible to cotrimoxazole, rifampin, vancomyin, daptomycin and linezolid. The MIC of vancomycin, measured by E-test, was ≥ 1.5 mg/L in 28 out of 34 cases (82.3%). CONCLUSIONS: Eleven percent of the MRSA strains isolated in our hospital are PVL positive. In general, skin and soft tissue infections are the most common and bacteremia or septic metastasis are frequent. In contrast to previous Spanish studies, more cases are observed in patients born in Spain and the infections are more severe.

Epidemiological study of resistance to nalidixic acid and other antibiotics in clinical Yersinia enterocolitica O:3 isolates.

Forty-six Yersinia enterocolitica O:3 clinical isolates resistant to nalidixic acid were studied. The use of molecular typing techniques, other indicators of resistance patterns, the plasmid profile, and the presence of genes that encode aminoglycoside-modifying enzyme production suggested to us a clonal dissemination of the studied strains.

Caracterización de enterobacterias portadoras de Blee aisladas de muestras invasivas / No disponible

No disponible