Julio García-Rodríguez

Infections caused by OXA-48-producing Klebsiella pneumoniae in a tertiary hospital in Spain in the setting of a prolonged, hospital-wide outbreak

OBJECTIVES We describe clinical and microbiological features of infections caused by OXA-48-producing Klebsiella pneumoniae (O48KP) in the setting of a prolonged, hospital-wide outbreak detected in January 2011. METHODS Clinical, demographic and microbiological data of patients with growth of O48KP in clinical specimens were collected until December 2011. PCR was used to detect carbapenemase and β-lactamase genes. The genetic relationships were determined by automated repetitive-sequence-based PCR. RESULTS Seventy-one patients with clinically guided cultures showing growth of O48KP were identified. Nine were considered to be colonizing rather than causing infection. The most frequent source of infection was the urinary tract (22/62), followed by surgical site infections (17/62). Blood cultures were positive in 23/62 patients. Many patients had significant comorbidity and prolonged hospital stays. In-hospital mortality among patients with O48KP infections was 43.5%. The MIC(90)s of ertapenem, imipenem and meropenem were >32, 16 and 16 mg/L, respectively. No single antimicrobial was active against all the isolates. The antibiotics most active against O48KP were amikacin (97.2% susceptible), colistin (90.1%), tigecycline (73%) and fosfomycin (66.2%). Although eight clones were identified, a predominant clone caused 73.2% of the infections. Multilocus sequence typing (MLST) of the predominant clone gave sequence type (ST) 405 and bla(TEM-1), bla(SHV-76), bla(CTX-M-15) and bla(OXA-1) genes and the insertion sequence IS1999 of the Tn1999 transposon were associated with bla(OXA-48) in this clone. CONCLUSIONS To our knowledge, this is the largest reported series of infections caused by O48KP in the setting of a single-centre outbreak and provides further input on the clinical relevance of infections caused by O48KP and the difficulties associated with its detection and control.

Initial Use of Echinocandins Does Not Negatively Influence Outcome in Candida parapsilosis Bloodstream Infection: A Propensity Score Analysis

BACKGROUND Concerns have arisen regarding the optimal antifungal regimen for Candida parapsilosis bloodstream infection (BSI) in view of its reduced susceptibility to echinocandins. METHODS The Prospective Population Study on Candidemia in Spain (CANDIPOP) is a prospective multicenter, population-based surveillance program on Candida BSI conducted through a 12-month period in 29 Spanish hospitals. Clinical isolates were identified by DNA sequencing, and antifungal susceptibility testing was performed by the European Committee on Antimicrobial Susceptibility Testing methodology. Predictors for clinical failure (all-cause mortality between days 3 to 30, or persistent candidemia for ≥72 hours after initiation of therapy) in episodes of C. parapsilosis species complex BSI were assessed by logistic regression analysis. We further analyzed the impact of echinocandin-based regimen as the initial antifungal therapy (within the first 72 hours) by using a propensity score approach. RESULTS Among 752 episodes of Candida BSI identified, 200 (26.6%) were due to C. parapsilosis species complex. We finally analyzed 194 episodes occurring in 190 patients. Clinical failure occurred in 58 of 177 (32.8%) of evaluable episodes. Orotracheal intubation (adjusted odds ratio [AOR], 2.81; P = .018) and septic shock (AOR, 2.91; P = .081) emerged as risk factors for clinical failure, whereas early central venous catheter removal was protective (AOR, 0.43; P = .040). Neither univariate nor multivariate analysis revealed that the initial use of an echinocandin-based regimen had any impact on the risk of clinical failure. Incorporation of the propensity score into the model did not change this finding. CONCLUSIONS The initial use of an echinocandin-based regimen does not seem to negatively influence outcome in C. parapsilosis BSI.

Efficacy of DNA amplification in tissue biopsy samples to improve the detection of invasive fungal disease

The performance of a pan-fungal PCR-based technique was evaluated to assess the aetiology of invasive fungal diseases (IFDs). A total of 89 formalin-fixed paraffin-embedded biopsy samples from 84 patients with proven IFD were studied. Culture of tissue was performed in 68 (81%) patients. The sensitivities of the PCR-based technique and microbiological culture of tissues were 89% and 56%, respectively (p <0.01). According to PCR results, Aspergillus species accounted for 67%, Candida species for 13%, zygomycetes for 11%, and rare and emerging fungi for 9%. Aspergillus species were significantly associated with lung samples (79.6%, p <0.01), Mucorales were associated with skin/subcutaneous samples, and Candida species were associated with gastrointestinal samples. Regarding biopsy samples with Aspergillus species, Aspergillus fumigatus DNA was detected in 43 of 50 (86%), and Aspergillus flavus in six of 50 (12%). PCR was positive in 24 of 30 (80%) cases with negative culture. In nine of the 84 patients, the PCR technique failed to amplify the DNA. Six also had negative cultures, and in the remaining three cases culture was positive (Rhizopus microsporus, Rhizopus arrhizus, and Sakseneae vasiformis), suggesting that the PCR technique was not as effective in amplifying the DNA of some species of Zygomycetes. In five cases, there was no correlation between culture results and those obtained with DNA amplification, indicating the possibility of a mixed infection or the presence of colonizer/contaminant microorganisms. In summary, PCR-based techniques for DNA amplification should be implemented in histopathology and microbiology departments, as they appear to be complementary to conventional methods for IFD detection.

Evaluation of matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry for identification of Candida parapsilosis, C. orthopsilosis and C. metapsilosis

We have evaluated matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry for the rapid identification of Candida parapsilosis, C. orthopsilosis and C. metapsilosis. A total of 103 isolates, including reference strains and clinical isolates, were identified by pyrosequencing of the ITS1 region and then assay by MALDI-TOF mass spectrometry. Concordance between the two methods was 100%, showing that MALDI-TOF may be useful as a rapid and reliable method for discrimination of species within the C. parapsilosis group.

Interhospital spread of NDM-7-producing Klebsiella pneumoniae belonging to ST437 in Spain

This study describes an interhospital spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) producing NDM-7 carbapenemase that started in December 2013 in Madrid, Spain. NDM-7-producing CRKP were isolated from urine, rectal swabs or blood samples from seven patients admitted to three different hospitals (Hospital Universitario La Paz, Hospital de Cantoblanco and Hospital Central de la Cruz Roja). The isolates were resistant to all antimicrobials tested except colistin and fosfomycin. One blood isolate was susceptible to minocycline and tigecycline but was resistant to fosfomycin. All isolates were closely related by pulsed-field gel electrophoresis (PFGE) and DiversiLab(®) analysis and belonged to multilocus sequence typing (MLST) sequence type 437. In addition, blaNDM-7, blaTEM-1, blaCTX-M-15 and aac(3)-IIa were identified. Family contacts of the index case were negative for NDM-producing bacteria. The outbreak occurred in two separate waves and the cases associated with Hospital de Cantoblanco had been admitted to the same room. Environmental samples from the trap of a sink and a shower in this room were positive for NDM-7-producing CRKP. To our knowledge, this is the first reported worldwide outbreak of NDM-7-producing CRKP. No relationship with the Indian continent, the Balkans or the Middle East could be established. Frequent transfer of aged or chronically ill patients between the facilities involved may have favoured the spread of NDM-7-producing CRKP. The spread of the second wave in Hospital de Cantoblanco probably occurred as a result of transmission from an environmental reservoir.

Mechanisms of linezolid-resistance among staphylococci in a tertiary hospital

ABSTRACT The mechanisms of linezolid resistance among 86 staphylococcal isolates from two intensive care units were investigated. The most frequent was the G2576T mutation in the 23S rRNA (82%). The cfr gene was found in 17% of the isolates, seven S. aureus and eight S. epidermidis isolates. Four of the S. epidermidis isolates had the G2576T mutation and the cfr gene. In four S. haemolyticus isolates, the mechanism could not be identified.

Empirical and targeted therapy of candidemia with fluconazole versus echinocandins: a propensity score–derived analysis of a population-based, multicentre prospective cohort

We compared the clinical efficacy of fluconazole and echinocandins in the treatment of candidemia in real practice. The CANDIPOP study is a prospective, population-based cohort study on candidemia carried out between May 2010 and April 2011 in 29 Spanish hospitals. Using strict inclusion criteria, we separately compared the impact of empirical and targeted therapy with fluconazole or echinocandins on 30-day mortality. Cox regression, including a propensity score (PS) for receiving echinocandins, stratified analysis on the PS quartiles and PS-based matched analyses, were performed. The empirical and targeted therapy cohorts comprised 316 and 421 cases, respectively; 30-day mortality was 18.7% with fluconazole and 33.9% with echinocandins (p 0.02) in the empirical therapy group and 19.8% with fluconazole and 27.7% with echinocandins (p 0.06) in the targeted therapy group. Multivariate Cox regression analysis including PS showed that empirical therapy with fluconazole was associated with better prognosis (adjusted hazard ratio 0.38; 95% confidence interval 0.17-0.81; p 0.01); no differences were found within each PS quartile or in cases matched according to PS. Targeted therapy with fluconazole did not show a significant association with mortality in the Cox regression analysis (adjusted hazard ratio 0.77; 95% confidence interval 0.41-1.46; p 0.63), in the PS quartiles or in PS-matched cases. The results were similar among patients with severe sepsis and septic shock. Empirical or targeted treatment with fluconazole was not associated with increased 30-day mortality compared to echinocandins among adults with candidemia.

Incidencia etaria y geográfica y patrón de sensibilidad a los antifúngicos de las especies de Candida causantes de candidemia en la población pediátrica española

INTRODUCTION There are few epidemiological studies on candidaemia in the paediatric population in Spain. We sought to determine the epidemiology of candidaemia in these patients. METHODS Prospective, observational and multicentre study in 44 Spanish hospitals. All candidaemia episodes in paediatric patients from 0 to 15 years old between January 2009 and February 2010 were studied. RESULTS There were 197 episodes and 200 species were isolated. The most frequent species was Candida parapsilosis sensu stricto (43%), followed by C. albicans (36%), C. tropicalis (6%), C. orthopsilosis, and C. glabrata (4%) respectively. C. albicans was the most prevalent in newborns, and C. parapsilosis was most frequent in the other age groups. As regards the regions of Spain, C. albicans was most prevalent in patients from Catalonia, the Balearic Islands and Canary Islands, and C. parapsilosis in patients from Andalusia, Castilla-León, Galicia, Valencia, and Madrid. The rate of resistance to fluconazole was 1.5% (4.1% with the new species-specific Clinical and Laboratory Standards Institute [CLSI] criteria). Fluconazole resistance was lower in neonates than the other age groups. The Neonatal Wards were the areas with most episodes (31.5%). In the multivariate analysis, the variables associated independently with candidaemia due to C. albicans were: catheter (OR: 5.967; 95% CI: 1.614-22.057; P=.007) and prematurity (OR: 2.229; 95% CI: 1.141- 4.631; P=.020). CONCLUSIONS The epidemiology of paediatric candidaemia varies between Spanish regions, but, globally, C. parapsilosis and C. albicans, are respectively, the first and second most frequently isolated species, and they show resistance rates to fluconazole of less than 5%.

Perspectives from Spanish infectious diseases professionals on 2009 A (H1N1) influenza: the third half

The first influenza pandemic in more than 40 years was declared in 2009. We aimed to evaluate the beliefs of Spanish infectious diseases professionals regarding several aspects of 2009 A (H1N1) influenza once the epidemic waned. An online survey was designed and distributed among members of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC). The survey considered hospital organization and preparedness planning and conduct, as well as the opinion of the infectious diseases professionals regarding several key issues. Between 7 March and 22 March 2010, 303 responses, corresponding to 12.8% of the SEIMC membership, were received. Of the respondents, 48.2% were microbiologists and 42.3% were clinicians dealing with infectious diseases. Forty-one per cent of respondents did not believe that 2009 A (H1N1) influenza had a more severe presentation than other seasonal influenzas. Only 5% fully agreed that 2009 A (H1N1) influenza had a more severe presentation. Influenza planning was available in 69.7% of represented institutions before the arrival of 2009 A (H1N1) influenza, and was considered to be useful, to different extents, by most professionals. In most institutions (88.3%), a multidisciplinary team was created to coordinate local pandemic influenza actions. The most successful protocols were those provided by regional healthcare authorities, followed by those from the CDC. The most problematic issues regarding 2009 A (H1N1) influenza were the management of patients in the emergency room and the vaccination and awareness of healthcare professionals (HCPs) regarding infection control. Microbiological diagnosis and the availability of antivirals were the least problematic areas. Although the majority of surveyed infectious diseases professionals did not believe that 2009 A (H1N1) influenza had an especially severe presentation, most of them agreed with the way that this epidemic was managed in their institutions.

Aplicación de la espectrometría de masas en micología

MALDI-TOF (matrix-assisted laser desorption ionization time-of-flight) mass spectrometry (MS) is becoming an essential tool in most microbiology laboratories. At present, by using a characteristic fungal profile obtained from whole cells or through simple extraction protocols, MALDI-TOF MS allows the identification of pathogenic fungi with a high performance potential. This methodology decreases the laboratory turnaround time, optimizing the detection of mycoses. This article describes the state-of-the-art of the use of MALDI-TOF MS for the detection of human clinical fungal pathogens in the laboratory and discusses the future applications of this technology, which will further improve routine mycological diagnosis.