Serotype epidemiology and multidrug resistance patterns of Salmonella enterica infecting humans in Italy

BACKGROUND: Salmonella enterica is the zoonotic agent most frequently responsible for foodborne infections in humans worldwide. In this work the presence of S. enterica was investigated in 734 unique enteropathogenic isolates collected from human patients between 2011 and 2012. RESULTS: All Salmonella spp. isolates were subjected to serotyping and antimicrobial susceptibility testing. Isolates displaying phenotypes and antimicrobial susceptibility profiles different from the reference strains were genotipically characterized. Several plasmid-embedded resistance determinants were identified and characterized. Non-typhoidal serotypes were most frequently diagnosed; monophasic Salmonella typhimurium 1,4 [5],12:i- and S. typhimurium represented the most prevalent serovars. Five isolates displayed phenotypes with extremely reduced susceptibility to antimicrobials: we detected multidrug resistance elements belonging to Ambler class A and class C in two non-typhoidal S. enterica serovars, i.e. Rissen and monophasic S. typhimurium 1,4 [5],12:i-, and in one typhoidal serovar, i.e., Paratyphi B. These resistance determinants have been so far almost exclusively associated with non-Salmonella members of the Enterobacteriaceae family. Alarmingly, two colistin resistant Salmonella enteritidis were also found. CONCLUSIONS: This work draws the attention to the still low, but rising, percentage of multidrug resistant Salmonella isolates infecting humans in Italy. Our results suggest that prompt monitoring of Salmonella serovar dissemination and resistance to antimicrobials is highly required

Prevalence, molecular epidemiology and intra-hospital acquisition of Klebsiella pneumoniae strains producing carbapenemases in an Italian teaching hospital from January 2015 to September 2016.

Objectives: We described Klebsiella pneumoniae producing carbapenemase (CPKP) spread from 01/01/2015 to 13/09/16 in a tertiary level hospital. Methods: The first positive surveillance rectal swab (SRS) or clinical sample (CS) collected in the medical department (MD), surgical department (SD) and intensive care department (ICD) were included in the study. A validated in-house Real-Time PCR method was used to detect carbapenemases; multilocus sequence typing (MLST) was used for further characterization of the strains. Results: 21535 patients were included: 213 CPKP strains from surveillance rectal swab (SRS) and 98 from clinical samples (CS) were collected. The percentage of CPKP detected in SRS with respect to CS increased in the medical MD from 2015 to 2016 (p = 0.01) and in ICD from 2012 to 2015 (p = 0.0001), while it decreased in SD from 2014 to 2016 (p = 0.003); 68.5% of the positive SRS had a previous negative SRS; CPKP was more frequently identified in CS than in SRS in MD. Twelve strains harboured more than one carbapenemase gene. Many other species harbouring a carbapenemase gene were collected. Conclusions: MDs need more inclusive surveillance criteria. The late detection of positive SRS underlined the risk of colonization during hospitalization

Intra-hospital acquisition of colonization and infection by Klebsiella pneumoniae strains producing carbapenemases and carriage evolution: A longitudinal analysis in an Italian teaching hospital from January 2017 to August 2019

Abstract Objectives We present an updated picture (1/1/2017–31/08/2019) of the frequency of carbapenemase producing Klebsiella pneumoniae (CPKP) in surveillance rectal swabs (SRS) and in clinical samples (CS) of patients admitted to a tertiary level hospital, focusing on longitudinal evolution of CPKP detected in SRS and on colistin resistant strains. Methods Retrospective longitudinal analysis. Only the first positive CPKP strain isolated from each patient was included. Results 638 CPKP strains were identified (471 in SRS and 167 in CS). SRS frequency increased over time in the medical department, remained high in the surgical department (SD) and decreased in the intensive care department. Most SRS–71.3%–and 49.1% of CS had nosocomial origin; about half of the SRS were identified in the SD. Regarding SRS evolution, carriage was confirmed in 39.5% of patients, no more testing in 25.5%, clinical involvement in 24.8 %, and negative result in 10.2%. Rates of colistin resistance were 20.1% in 2017, 31.2% in 2018 and 26.9% in 2019. Conclusions CPKP diffusion is still an important issue despite the surveillance program. It is vital to enhance medical staff's awareness on this because most CPKP first detections in SRS occurred during hospital stay due to a nosocomial acquisition with a comparable picture over time. Colistin resistance is increasing

Prevalence of Klebsiella pneumoniae strains producing carbapenemases and increase of resistance to colistin in an Italian teaching hospital from January 2012 To December 2014

The aim of this study was to characterize the spread of carbapenemase-producing Klebsiella pneumoniae (CPKP) in a tertiary level hospital using ongoing active surveillance with rectal swab cultures. Furthermore, this study analyzed the presence of CPKP in the clinical samples (CS) of a single patient as well as the evolution of Colistin-sensitive strains (CoS) to Colistin-resistant strains (CoR)

Modeling the contribution of male testosterone levels to the duration of positive COVID testing among hospitalized male COVID-19 patients

Background: A growing body of evidence is emerging suggesting testosterone can affect all cells involved in the immune response to both bacterial and viral infections, and the testosterone effect on the immune response could explain the greater susceptibility of men to infections including COVID-19. We aimed to explore the predictive role of male serum total testosterone (TT) levels on the time till viral negativity testing among hospitalized COVID-19 patients. Methods: The univariate effect of risk factors for the duration of COVID-19 viral positivity was evaluated using the log-rank test and Kaplan-Meier estimates. A multivariable Cox regression model was developed to test the role of TT levels and the subsequent odds for shorter viral positivity intervals. Results: Increasing serum TT levels and the need for an oxygen administration strategy were independently predictive for respectively reduced and increased days to negativization (Hazard Ratio [HR]: 1.39, 95% CI: 0.95-2.03 and HR: 0.19, 95% CI: 0.03-1.18). Conclusion: Baseline higher TT levels for male COVID-19 patients at hospital admission are associated with shorter durations of positive COVID-19 testing and thus viral clearance. Our preliminary findings might play a relevant to help pandemic control strategies if these will be verified in future larger multicentric and possibly randomized trials

Efficacy of three BCG strains (Connaught, TICE and RIVM) with or without secondary resection (re-TUR) for intermediate/high-risk non-muscle-invasive bladder cancers: results from a retrospective single-institution cohort analysis

PURPOSE: (I) To evaluate the clinical efficacy of three different BCG strains in patients with intermediate-/high-risk non-muscle-invasive bladder cancer (NMIBC). (II) To determine the importance of performing routine secondary resection (re-TUR) in the setting of BCG maintenance protocol for the three strains.METHODS: NMIBCs who received an adjuvant induction followed by a maintenance schedule of intravesical immunotherapy with BCG Connaught, TICE and RIVM. Only BCG-naive and those treated with the same strain over the course of follow-up were included. Cox proportional hazards model was developed according to prognostic factors by the Spanish Urological Oncology Group (CUETO) as well as by adjusting for the implementation of re-TUR.RESULTS: n=422 Ta-T1 patients (Connaught, n=146; TICE, n=112 and RIVM, n=164) with a median (IQR) follow-up of 72 (60-85) were reviewed. Re-TUR was associated with improved recurrence and progression outcomes (HRRFS: 0.63; 95% CI 0.46-0.86; HRPFS: 0.55; 95% CI 0.31-0.86). Adjusting for CUETO risk factors and re-TUR, BGC TICE and RIVM provided longer RFS compared to Connaught (HRTICE: 0.58, 95% CI 0.39-0.86; HRRIVM: 0.61, 95% CI 0.42-0.87) while no differences were identified between strains for PFS and CSS. Sub-analysis of only re-TUR cases (n=190, 45%) showed TICE the sole to achieve longer RFS compared to both Connaught and RIVM.CONCLUSION: Re-TUR was confirmed to ensure longer RFS and PFS in intermediate-/high-risk NMIBCs but did not influence the relative single BCG strain efficacy. When routinely performing re-TUR followed by a maintenance BCG schedule, TICE was superior to the other strains for RFS outcomes

Stool-specimen testing practices adopted by clinical microbiology laboratories in the Veneto Region, Italy

In order to correctly analyze data of laboratory diagnoses of infectious gastroenteritis for epidemiological purposes, a survey on analytical methods applied by hospital-based clinical microbiology laboratories has been conducted in the Veneto Region (Italy). The survey has been carried out in 2005 through a questionnaire collecting data on laboratory protocols and materials used for faecal specimens analysis. Laboratories from all the Local Health Units and University Hospitals of the Region returned the questionnaire. Almost all the laboratories routinely tested for the main foodborne pathogens: 23/23 for Salmonella, 22/23 for Shigella and 19/23 for Campylobacter jejuni. A great variety of analytical methods was applied for pathogen isolation; among these is worth of notice the inappropriate use of selenite broth for Shigella enrichment.Among noncultural methods, immunoassays were largely adopted. The survey allowed to appraise stool-specimen testing practices among laboratories of the Veneto Region; overall the compliance with guidelines proposed by the main national and international scientific societies resulted rather good

Talking of... Dientamoeba fragilis

Introduction: Dientamoeba fragilis is a protozoan parasite of human gastrointestinal tract with worldwide distribution and a controversial pathogenic role. Data on prevalence and geographical distribution are underestimated for difficult microscopic recognition and “fragility” of the protozoan. Generally to perform the O & P exam for identification of D. fragilis it is necessary to recur to a permanent stain and to an expert microscopist. Methods: we analyzed fecal samples of 3907 patients enrolled among the patients referred to the Service of Microbiology of Padova University Hospital for routine parassitology examinations from June 2011 to June 2012. The aim of this study was to document the prevalence and the clinical features of D. fragilis infection. The laboratory detection rate of the organism is greatly enhanced by use of preservative to fix stool specimens immediately after passage. As previously described for a rapid identification of D. fragilis, in unstained fixed fecal material by direct microscopy (400X), the demonstration of the characteristic “golf-club” and “acanthopodia-like” structures are suitable. Results: in this study the prevalence was found to be 6.8%, higher than our previous reports. Out of the 267 patients in which we detected D. fragilis, 26.0% presented with extra-intestinal symptoms, 19.8% reported gastrointestinal complaints and 17.0% referred abdominal pain. Conclusions: D. fragilis, even if considered a neglected parasite, is not rare and the presence of this fecal agent is associated to various intestinal and probably systemic clinical symptoms, even though asymptomatic carriers have been reported. D. fragilis infects in high rates among close household contacts; so the Authors stress the importance of screening close contacts to prevent re-infections after treatment

Multilocus sequence typing of Campylobacter jejuni and Campylobacter coli from humans and chickens in North-Eastern Italy.

This paper reports the multilocus sequence typing (MLST) of 57 C. jejuni and C. coli isolates from humans and chickens in Italy and the identification of 17 new sequence types (STs). A high genetic diversity was detected among C. jejuni/C. coli and human/chicken isolates, with a predominance of clonal complexes CC21 and CC828. Although human STs were not the same as those found in chickens, 3 CCs overlapped between human and chicken isolates. Genotyping of Campylobacter strains by MLST should be encouraged in order to implement surveillance and con- trol of infection in humans and in animal reservoirs in Italy