Tsioutis, Constantinos

Limited data exist regarding prognostic factors and optimal antimicrobial treatment of infections caused by extensively drug-resistant Acinetobacter baumannii (XDR-AB). This retrospective cohort study included 93 adult patients who developed ventilator-associated pneumonia (VAP) due to XDR-AB in the ICU of the University Hospital of Heraklion, Greece, from October 2012 to April 2015. XDR-AB isolates were mainly susceptible to colistin (93.5%) and tigecycline (25.8%), whereas 6 (6.5%) were pandrug-resistant. Prior to infection, patients had long durations of mechanical ventilation and hospital stay and multiple exposures to antibiotics. Median Charlson co-morbidity and APACHE II scores were 2 and 17, respectively. Mortality at 28 days of infection onset was high (34.4%) despite high rates of in-vitro-active empirical (81.7%) and definitive (90.3%) treatment. Active colistin-based combination therapy (n = 55) and monotherapy (n = 29) groups had similar 28-day mortality (27.6% vs. 30.9%, respectively) and Kaplan–Meier survival estimates over time. In multivariable Cox regression, advanced age (aHR = 1.05 per year increase, 95% CI 1.02–1.09), rapidly fatal underlying disease (aHR = 2.64, 95% CI 0.98–9.17) and APACHE II score (aHR = 1.06 per unit increase, 95% CI 0.99–1.14) were identified as independent predictors of 28-day mortality, but no difference in mortality hazards between the active colistin-based combination therapy and monotherapy groups was produced (aHR = 0.88, 95% CI 0.35–2.38). These results support the use of colistin as a first-line agent against VAP in settings where XDR-AB is endemic, but oppose the introduction of colistin-based combination therapy as standard treatment.

Background: In this first attempt to implement a standardized surveillance system of surgical site infections (SSI) in a Greek hospital, our objective was to identify areas for improvement by comparing main epidemiologic and microbiologic features of SSI with international data. Methods: The National Nosocomial Infections Surveillance (NNIS) system protocols were employed to prospectively collect data for patients in 8 surgical wards who underwent surgery during a 9-month period. SSI rates were benchmarked with international data using standardized infection ratios. Risk factors were evaluated by multivariate logistic regression. Results: A total of 129 SSI was identified in 2420 operations (5.3%), of which 47.3% developed after discharge. SSI rates were higher for 2 of 20 operation categories compared with Spanish and Italian data and for 12 of 20 categories compared with NNIS data. Gram-positive microorganisms accounted for 52.1% of SSI isolates, and Enterococci were predominant. Alarming resistance patterns for Enterococcus faecium and Acinetobacter baumannii were recorded. Potentially modifiable risk factors for SSI included multiple procedures, extended duration of operation, and antibiotic prophylaxis. SSI was associated with prolongation of postoperative stay but not with mortality. Conclusion: Comparisons of surveillance data in our hospital with international benchmarks provided useful information for infection control interventions to reduce the incidence of SSI.

Data concerning clinical characteristics, microbiology, treatment and outcomes of external ventricular drainage-associated infections (EVDAI) are limited. All hospitalized patients with EVDAI in a University Hospital between January 2009 and December 2015 were retrospective recorded. Only the first episode per patient was included. An antibiotic was considered “active” when its pharmacokinetic properties were appropriate for EVDAI and the implicated microorganism was in vitro susceptible. During the 7-year study period, 36 EVDAI were identified. Median patient age was 53years and 23 (63.9%) were male. Catheter types were intraventricular (70.6%) and lumbar (29.4%). Median catheterization duration before infection was 14days. Gram-negative bacteria (GNB) predominated (57.9%), followed by gram-positives (36.8%) and fungi (5.3%). Administered antibiotics were considered “active” in 69.4% of empirical and in 86.1% of definitive treatment regimens. In 10 infections, intraventricular/intrathecal (IVT) antibiotics were administered. Eleven patients died (30.6%) during hospitalization. Patients who died had higher rates of EVDAI by GNB (p=0.011) and higher rates of treatment with intravenous colistin (p=0.019 for empirical and p=0.006 for definitive colistin). Compared to EVDAI by other pathogens, patients with EVDAI by GNB had longer catheter-days before infection (p<0.001) and higher mortality (p=0.011). In our study, GNB were a frequent cause of EVDAI, and were related with high rates of inactive treatment and mortality. Intravenous colistin alone is not effective and treatment should include IVT antibiotics and intravenous antibiotics that achieve adequate CSF levels.

mcr-1 has been reported as the first plasmid-encoded gene conferring colistin resistance. In KPC-producing Klebsiella pneumoniae (KPC-KP), however, colistin resistance is rapidly emerging through other mechanisms. Resistance is frequently due to disruption of the mgrB gene by insertion sequences, e.g. ISL3. The aim of this study was to investigate the expansion of mgrB-mutated KPC-KP isolates. In addition, the localisation and targets of ISL3 sequences within the core and accessory genome of common KPC-KP lineages were identified. A total of 29 clinical K. pneumoniae isolates collected from Italian patients were randomly selected. Whole genome sequences were analysed for resistance genes, plasmids and insertion sequences. In addition, 27 colistin-resistant KPC-KP isolates from a previous study from Crete (Greece) were assessed. Clonal expansion of KPC-KP isolates with various mutations in mgrB among all lineages was observed. In two Italian MLST ST512 isolates and eight Greek ST258 isolates, an identical copy of ISL3 was inserted in mgrB nucleotide position 133. ISL3, a transposable restriction–modification system of 8154 nucleotides, was located on pKpQIL-like plasmids and may transpose into the chromosome. In four isolates, chromosomal integration of ISL3 in diverse inner membrane proteins other than mgrB was identified. Colistin resistance is most often explained by clonal expansion of isolates with mutated mgrB. pKpQIL-like plasmids, which are omnipresent in KPC-KP, carry insertion sequences such as ISL3 that have mgrB as a target hotspot for transposition. Transposition of insertion sequences from plasmids and subsequent clonal expansion may contribute to the emerging colistin resistance in KPC-KP.

A 54-year-old otherwise healthy male, who was being evaluated for prolonged fever, developed clinical and ultrasonographic signs compatible with acute acalculous cholecystitis. Diagnosis of murine typhus was confirmed by serology and the patient was treated with doxycycline. He improved rapidly and all clinical and laboratory abnormalities returned to normal. The present case dictates that knowledge of the local epidemiology and keeping a high index of clinical suspicion can help recognize uncommon manifestations of murine typhus, in order to treat appropriately and avoid unnecessary investigations and interventions.

Background: The characteristics of Rickettsia typhi infection in elderly patients have not been extensively described in the literature. Methods: We conducted a prospective study on murine typhus in patients > 65 years old in two endemic areas of Greece. Results: Forty-nine elderly patients were analyzed, including 30 (61.2%) males. The clinical triad of fever (100% of patients), headache (83.7%), and rash (73.5%), occurred in 63% of patients, whereas malaise (85.7%), anorexia (65.3%), and myalgia (59.2%) were also common. Frequent laboratory findings were transaminasemia (89.8%), lactate dehydrogenase elevation (65.3%), hematuria (55.1%), thrombocytopenia (53.1%), anemia (51%), leucopenia (40.8%), and mild hyponatremia (23.5%). Complications developed in 16 patients (32.7%); no deaths were recorded. Conclusions: The main clinical and laboratory characteristics of murine typhus are similar in elderly and younger adults. However, elderly patients have a more severe clinical picture, evidenced by a higher complication rate and longer duration of fever, even with appropriate treatment. To our knowledge, this is the first study to focus on murine typhus in a geriatric population.

Public awareness and advances in the diagnostic approach to Q fever have provided important information on epidemiological and clinical aspects of this zoonosis. Coxiella burnetii infection exhibits various acute or chronic clinical forms, and infection during pregnancy may jeopardize the integrity of the fetus. The presentation of infection is often nonspecific and this hinders prompt diagnosis. Therapeutic regimens vary, and treating Q fever during pregnancy and childhood is often challenging. Increasing clinical experience with C. burnetii infections has helped create treatment protocols and follow-up algorithms that have considerably improved management and prognosis. Vaccines are available, although their use is still limited.

We describe a case of Streptomyces lanatus pneumonia in an immunocompetent 52-year-old woman. Bronchoalveolar lavage culture grew Streptomyces, which was identified by 16S rRNA sequencing. The infection resolved completely after successful treatment with doxycycline for 6 months. We also review the literature on human invasive Streptomyces infections.