Clinical characteristics and outcome of bacteraemia caused by Enterobacter cloacae and Klebsiella aerogenes: more similarities than differences.

OBJECTIVES: The genus Enterobacter is a common cause of nosocomial infections. Historically, the most frequent Enterobacter species were those of Enterobacter cloacae complex and Enterobacter aerogenes. In 2019, E. aerogenes was re-classified as Klebsiella aerogenes owing to its higher genotypic similarity with the genus Klebsiella. Our objective was to characterise and compare the clinical profiles of bacteraemia caused by E. cloacae and K. aerogenes. METHODS: This 3-year multicentre, prospective cohort study enrolled consecutive patients with bacteraemia by E. cloacae or K. aerogenes. Baseline characteristics, bacteraemia features (source, severity, treatment), antibiotic susceptibility, resistance mechanisms and mortality were analysed. RESULTS: The study included 285 patients with bacteraemia [196 (68.8%) E. cloacae and 89 (31.2%) K. aerogenes]. The groups showed no differences in age, sex, previous use of invasive devices, place of acquisition, sources or severity at onset. The Charlson score was higher among patients with E. cloacae bacteraemia [2 (1-4) vs. 1 (0.5-3); P = 0.018], and previous antibiotic therapy was more common in patients with K. aerogenes bacteraemia (57.3% vs. 41.3%; P = 0.01). Mortality was 19.4% for E. cloacae and 20.2% for K. aerogenes (P = 0.869). Antibiotic susceptibility was similar for both species, and the incidence of multidrug resistance or ESBL production was low (6% and 5.3%, respectively), with no differences between species. CONCLUSION: Bacteraemias caused by E. cloacae and K. aerogenes share similar patient profiles, presentation and prognosis. Patients with E. cloacae bacteraemia had more co-morbidities and those with K. aerogenes bacteraemia had received more antibiotics.

HCV microelimination strategies: An interventional study in diagnosed patients without access to the system.

Hepatitis C virus (HCV) one-step diagnosis improves recovery in patients with active infection. However, patients with previous anti-HCV+ may be excluded. We aimed to identify and retrieve non-referred or lost-to-follow-up HCV-infected patients. All anti-HCV+ patients seen in our hospital between 2013 and 2018 were included. In the first phase, we identified anti-HCV+ patients who were not referred to the Gastroenterology Unit (GU) or lost-to-follow-up. In the second phase, recovered patients were invited for a one-step visit for liver evaluation. A total of 1330 anti-HCV+ patients were included: 21.7% had not been referred to GU, and 23.1% were lost-to-follow-up. In the second phase, 49.6% of patients were contacted, and 92.8% attended a medical consultation: 62.7% had active infection, 92.2% were treated, and 86.5% achieved SVR (ITT). We concluded that screening microbiological data and referring unidentified patients with active HCV infection directly to specialists is an effective tool in achieving HCV microelimination.

A prospective, multicenter case control study of risk factors for acquisition and mortality in Enterobacter species bacteremia.

BACKGROUND: Enterobacter is among the main etiologies of hospital-acquired infections. This study aims to identify the risk factors of acquisition and attributable mortality of Enterobacter bacteremia. METHODS: Observational, case-control study for risk factors and prospective cohort for outcomes of consecutive cases with Enterobacter bacteremia. This study was conducted in five hospitals in Spain over a three-year period. Matched controls were patients with negative blood cultures and same sex, age, and hospitalization area. RESULTS: The study included 285 cases and 570 controls. E. cloacae was isolated in 198(68.8%) cases and E. aerogenes in 89(31.2%). Invasive procedures (hemodialysis, nasogastric tube, mechanical ventilation, surgical drainage tube) and previous antibiotics or corticosteroids were independently associated with Enterobacter bacteremia. Its attributable mortality was 7.8%(CI95%2.7-13.4%), being dissimilar according to a McCabe index: non-fatal=3.2%, ultimately fatal=12.9% and rapidly fatal=0.12%. Enterobacter bacteremia remained an independent risk factor for mortality among cases with severe sepsis or septic shock (OR 5.75 [CI95%2.57-12.87], p<0.001), with an attributable mortality of 40.3%(CI95%25.7-53.3). Empiric therapy or antibiotic resistances were not related to the outcome among patients with bacteremia. CONCLUSIONS: Invasive procedures, previous antibiotics and corticosteroids predispose to acquire Enterobacter bacteremia. This entity increases mortality among fragile patients and those with severe infections. Antibiotic resistances did not affect the outcome.

First report of NDM-1-producing clinical isolate of Leclercia adecarboxylata in Spain.

We describe the case of NDM-1-producing Leclercia adecarboxylata recovered from the clinical sample of a patient hospitalized for a trauma-related injury to his foot. The isolate was resistant to all beta-lactams, quinolones, trimetroprim-sulfametoxazol, gentamicin and tobramicyn. The blaNDM-1 gene was located in a conjugative plasmid that also contained the blaSHV-12 gene and was preceded by a disrupted insertion sequence of ISAba125. The plasmid belongs to the incompatibility group X3, which is known to be an important vector for NDM-1 dissemination in China. This is the first reported case of NDM-1L. adecarboxylata in our country and evidences that species of uncertain clinical relevance can act as hidden sources of clinically important resistance determinants.

[Small-colony variants of Staphylococcus aureus: Usefulness of various test for diagnosis and susceptibility study]. / Variantes pequeñas de Staphylococcus aureus: utilidad de distintas pruebas para su diagnóstico y estudio de sensibilidad.

INTRODUCTION: Small colony variants of Staphylococcus aureus (SCVSA) are a sub-population with special features. METHODS: The phenotypic features and antibiotic susceptibility of four clinical isolates SCVSA were studied. RESULTS: Colonies grew in the usual culture media, except in Mueller Hinton. All isolates were resistant to ciprofloxacin and co-trimoxazole. DISCUSSION: As SCVSA are isolated with low frequency, it is necessary to determine the optimal methods for their identification and antibiotic susceptibility study.

[Molecular typing methods for infection monitoring and control]. / Técnicas de tipificación molecular para la vigilancia y control de la infección.

Molecular typing methods are useful in the surveillance and control of nosocomial outbreaks because they can provide information on the clonal relatedness among isolates, identify reservoirs, and determine routes of transmission. The gold standard assay for molecular typing is pulsed-field gel electrophoresis (PFGE) due to its high discriminatory power. Some major disadvantages of PFGE include the high cost of the equipment, its labor intensiveness (the technique is not automated) and the time required to analyze the profiles of DNA bands (pulsotypes). Although there are many molecular typing methods based on polymerase-chain reaction (PCR), the most widely used is repetitive sequence-based PCR (REP-PCR). Most of the PCR techniques used for molecular typing have none of the limitations of PFGE as they are less expensive and labor intensive (some, such as bioMérieux's Diversilab system, are commercially available) and generate DNA profiles that are easier to interpret, depending on the microorganism. The discriminatory power of PCR is generally lower than or similar to that of PFGE. Both PFGE and PCR require optimal laboratory standardization to guarantee good reproducibility. PCR methods are preferable in the study of small, timelimited outbreaks. In more complex outbreaks of longer duration, in which clonal evolution and dynamics are studied, the use of PFGE is preferable. Molecular typing methods based on DNA sequencing, such as multilocus sequence typing, are applicable in global epidemiological studies or in analyses of the population structure of microorganisms.