Enterobacterales carrying chromosomal AmpC β-lactamases in Europe (EuESCPM): Epidemiology and antimicrobial resistance burden from a cohort of 27 hospitals, 2020-2022

INTRODUCTION

The ESCPM group (Enterobacter species including Klebsiella aerogenes - formerly Enterobacter aerogenes, Serratia species, Citrobacter freundii complex, Providencia species and Morganella morganii) has not yet been incorporated into systematic surveillance programs.

METHODS

We conducted a multicentre retrospective observational study analysing all ESCPM strains isolated from blood cultures in 27 European hospitals over a 3-year period (2020-2022). Diagnostic approach, epidemiology, and antimicrobial susceptibility were investigated.

RESULTS

Our study comprised 6,774 ESCPM isolates. MALDI-TOF coupled to mass spectrometry was the predominant technique for bacterial identification. Susceptibility to new β-lactam/β-lactamase inhibitor combinations and confirmation of AmpC overproduction were routinely tested in 33.3% and 29.6% of the centres, respectively. The most prevalent species were E. cloacae complex (44.8%) and S. marcescens (22.7%). Overall, third-generation cephalosporins (3GC), combined third- and fourth-generation cephalosporins (3GC + 4GC) and carbapenems resistance phenotypes were observed in 15.7%, 4.6%, and 9.5% of the isolates, respectively. AmpC overproduction was the most prevalent resistance mechanism detected (15.8%). Among carbapenemase-producers, carbapenemase type was provided in 44.4% of the isolates, VIM- (22.9%) and OXA-48-enzyme (16%) being the most frequently detected. E. cloacae complex, K. aerogenes and Providencia species exhibited the most notable cumulative antimicrobial resistance profiles, with the former displaying 3GC, combined 3GC + 4GC and carbapenems resistance phenotypes in 15.2%, 7.4%, and 12.8% of the isolates, respectively. K. aerogenes showed the highest rate of both 3GC resistant phenotype (29.8%) and AmpC overproduction (32.1%), while Providencia species those of both carbapenems resistance phenotype (42.7%) and carbapenemase production (29.4%). ESCPM isolates exhibiting both 3GC and combined 3GC + 4GC resistance phenotypes displayed high susceptibility to ceftazidime/avibactam (98.2% and 95.7%, respectively) and colistin (90.3% and 90.7%, respectively). Colistin emerged as the most active drug against ESCPM species (except those intrinsically resistant) displaying both carbapenems resistance phenotype (85.8%) and carbapenemase production (97.8%).

CONCLUSIONS

This study presented a current analysis of ESCPM species epidemiology in Europe, providing insights to inform current antibiotic treatments and guide strategies for antimicrobial stewardship and diagnostics.

From Forgotten Pathogen to Target for New Vaccines: What Clinicians Need to Know about Respiratory Syncytial Virus Infection in Older Adults

Respiratory syncytial virus (RSV) is increasingly recognized as being implicated in acute illness in older adults, with a significant weight in hospitalizations for respiratory illness and death. By means of a best-evidence review, this paper aims to investigate whether RSV can be considered a forgotten pathogen in older patients, looking at trends in the literature volume and exploring possible epidemiological and clinical features underlying the focus given to it. We then present an assessment of its disease burden and present and future strategies for its reduction, particularly in light of the recent availability of new vaccines.

Performance evaluation of Bruker UMIC® microdilution panel and disc diffusion to determine cefiderocol susceptibility in Enterobacterales, Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Achromobacter xylosoxidans and Burkolderia species

PURPOSE

Cefiderocol susceptibility testing (AST) represents an open challenge for clinical microbiology. Herein, we evaluated the performance of the UMIC® Cefiderocol broth microdilution (BMD) test and disc diffusion on Gram-negative species.

METHODS

UMIC® Cefiderocol BMD test, disc diffusion and reference BMD were in parallel performed on a collection of 256 clinical isolates. Categorical agreement (CA), essential agreement (EA), bias, major errors (MEs) and very major errors (VMEs) were calculated for both AST methods.

RESULTS

The UMIC® Cefiderocol BMD strip exhibited an EA < 90% (85.5%), a CA higher than 90% (93.7%) and a low number of VMEs (n = 4, 4.2%) and MEs (n = 12, 7.4%). UMIC® Cefiderocol identified 96.2% of the resistant isolates [Enterobacterales, (39/40); P. aeruginosa (19/19); A. xylosoxidans (5/6); S. maltophilia (5/6); Burkholderia spp. (8/8)]. Disc diffusion showed a high CA (from 94.9 to 100%) regardless of disc manufacturer in Enterobacterales, P. aeuroginosa, A. baumannii and S. maltophilia. However, high rates of results falling in the area of technical uncertainty (ATU) were observed in Enterobacterales (34/90, 37.8%) and P. aeruginosa (16/40, 40%). Disc diffusion showed a poor performance in A. xylosoxidans and Burkholderia spp. if PK/PD breakpoint was used (overall, 5/9 VMEs; in contrast, the use of P. aeruginosa-specific breakpoints resulted in 100% of CA with 24.6% of results in the ATU).

CONCLUSION

In conclusion, disc diffusion and UMIC® Cefiderocol are valid methods for the determination of cefiderocol susceptibility. Given the high number of results in the ATU by disc diffusion, a combined use of both AST methods may represent a solution to overcome the challenge of cefiderocol susceptibility testing in routine microbiology laboratories.

Prevalence and mortality of ceftazidime/avibactam-resistant KPC-producing Klebsiella pneumoniae bloodstream infections (2018-2022)

INTRODUCTION

Ceftazidime/avibactam-resistance in Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) is a topic of great interest for epidemiological, diagnostic, and therapeutical reasons. However, data on its prevalence and burden on mortality in patients with bloodstream infection (BSI) are lacking. This study was aimed at identifying risk factors for mortality in patients suffering from ceftazidime/avibactam-resistant KPC-Kp BSI.

METHODS

An observational retrospective study (January 2018-December 2022) was conducted at a tertiary hospital including all consecutive hospitalized adult patients with a ceftazidime/avibactam-resistant KPC-Kp BSI. Data on baseline clinical features, management, and admission outcomes were analyzed.

RESULTS

Over the study period, among all the KPC-Kp BSI events recorded, 38 (10.5%) were caused by ceftazidime/avibactam-resistant KPC-Kp strains, 37 events being finally included. The ceftazidime/avibactam-resistant KPC-Kp strains revealed susceptibility restoration to at least one carbapenem in more than 60% of cases. In-hospital and 30-day all-cause mortality rates were 22% and 16.2%, respectively. Non-survivors suffered from more baseline comorbidities and experienced a more severe ceftazidime/avibactam-resistant KPC-Kp BSI presentation (i.e., both the Pitt Bacteremia and INCREMENT-CPE scores were significantly higher). Presenting with a higher Charlson Comorbidity Index, chronic kidney disease-KDIGO stage 3A or worse-having recently gone through renal replacement therapy, having suffered from an acute kidney injury following the ceftazidime/avibactam-resistant KPC-Kp BSI, and being admitted for cardiac surgery were the strongest predictors of mortality.

CONCLUSION

Ceftazidime/avibactam resistance in KPC-Kp BSI easily emerged in our highly KPC-Kp endemic area with remarkable mortality rates. Our findings might provide physicians possibly actionable information when managing patients with a ceftazidime/avibactam-resistant KPC-Kp BSI.

Bloodstream Infections by Pantoea Species: Clinical and Microbiological Findings from a Retrospective Study, Italy, 2018-2023

(1) Background: The widespread use of MALDI-TOF coupled to mass spectrometry has improved diagnostic accuracy by identifying uncommon bacteria. Among Enterobacterales, Pantoea species have been seen to be implicated in several human infections, but their clinical and microbiological framework is currently based on a few anecdotal reports. (2) Methods: We conducted this five-year (2018-2023) single-center study aimed at investigating the prevalence and clinical and microbiological findings of Pantoea species bloodstream infections. (3) Results: Among the 4996 bloodstream infection Gram-negative isolates collected during the study period, Pantoea species accounted for 0.4% (n = 19) of isolates from 19 different patients, 5 of them being pediatric cases. Among Pantoea species isolates, P. agglomerans was the most frequently detected (45%; n = 9) followed by P. eucrina (30%; n = 6) and P. septica (15%; n = 3). Malignancy (35.7%) in adults and malignancy (40%) and cerebrovascular disease following meconium aspiration (40%) in pediatric patients as comorbidities and shivering and/or fever following parenteral infusion (36.8%) as a symptom/sign of Pantoea species bloodstream infection onset were the most frequently observed clinical features. Among adults, primary bloodstream infection was the most frequent (50%), whereas among pediatric patients, the most commonly identified sources of infection were catheter-related (40%) and the respiratory tract (40%). Overall, Pantoea species bloodstream infection isolates displayed high susceptibility to all the antibiotics except for ampicillin (63.2%), fosfomycin (73.7%), and piperacillin/tazobactam (84.2%). Targeted antibiotic treatment was prescribed as monotherapy for adults (71.4%) and combination therapy for pediatric patients (60%). The most prescribed antibiotic regimens were piperacillin/tazobactam (21.4%) in adults and meropenem- (40%) and aminoglycoside-containing (40%) antibiotics in pediatric patients. The overall 28-day all-cause mortality rate was 5.3% (n = 1). (4) Conclusions: The prevalence and 28-day mortality rate of Pantoea species bloodstream infections were low. The prescription of targeted therapy including broad-spectrum antibiotics could indicate an underestimation of the specific involvement of the Pantoea species in the onset of the disease, warranting further studies defining their pathogenic potential.

Prevalence and Impact on Mortality of Colonization and Super-Infection by Carbapenem-Resistant Gram-Negative Organisms in COVID-19 Hospitalized Patients

BACKGROUND

The relationship between superinfection by multidrug-resistant Gram-negative bacteria and mortality among SARS-CoV-2 hospitalized patients is still unclear. Carbapenem-resistant Acinetobacter baumannii and carbapenemase-producing Enterobacterales are among the most frequently isolated species when it comes to hospital-acquired superinfections among SARS-CoV-2 patients.

METHODS

Herein, a retrospective study was carried out using data from adult patients hospitalized for COVID-19. The interaction between in-hospital mortality and rectal carriage and superinfection by carbapenemase-producing Enterobacterales and/or carbapenem-resistant Acinetobacter baumannii was assessed.

RESULTS

The incidence of KPC-producing Klebsiella pneumoniae and/or carbapenem-resistant Acinetobacter baumannii rectal carriage was 30%. Bloodstream infection and/or pneumonia due to KPC-producing Klebsiella pneumoniae and/or carbapenem-resistant Acinetobacter baumannii occurred in 20% of patients. A higher Charlson comorbidity index (OR 1.41, 95% CI 1.24-1.59), being submitted to invasive mechanical ventilation/ECMO ≥ 96 h (OR 6.34, 95% CI 3.18-12.62), being treated with systemic corticosteroids (OR 4.67, 95% CI 2.43-9.05) and having lymphopenia at the time of admission (OR 0.54, 95% CI 0.40-0.72) were the features most strongly associated with in-hospital mortality.

CONCLUSIONS

Although KPC-producing Klebsiella pneumoniae and/or carbapenem-resistant Acinetobacter baumannii rectal carriage, and/or bloodstream infection/pneumonia were diagnosed in a remarkable percentage of COVID-19 patients, their impact on in-hospital mortality was not significant. Further studies are needed to assess the burden of antimicrobial resistance as a legacy of COVID-19 in order to identify future prevention opportunities.

Performance Evaluation of BD Phoenix and MicroScan WalkAway Plus for Determination of Fosfomycin Susceptibility in Enterobacterales

BACKGROUND

Fosfomycin is an old bactericidal drug that has gained increasing interest in the last decade for its potential use in multi-drug resistant gram-negative infections. However, evidence on fosfomycin susceptibility testing reports a poor correlation between commercial methods vs. reference agar dilution (AD) for Enterobacterales (EB). The study aimed at assessing the performance of two automated systems for the determination of fosfomycin susceptibility in EB clinical isolates.

METHODS

Fosfomycin susceptibility testing results of two collections of 100 non-duplicate clinical EB strains obtained using two different platforms (BD Phoenix and MicroScan WalkAway Plus) were compared with those obtained by AD. Categorical agreement (CA), major error (ME) and very major error (VME) rates were calculated.

RESULTS

BD Phoenix exhibited a 6.9% rate of false-resistant results and achieved a CA of 69%, whereas MicroScan WalkAway Plus achieved 3.7% of false-resistant results and 72% of CA. Both automated systems showed poor detection of resistant isolates, with 49.1% and 56.2% of false-susceptible results for BD Phoenix and Microscan WalkAway Plus, respectively.

CONCLUSIONS

Overall, agar dilution remains the most suitable method for routine laboratory antimicrobial susceptibility testing of fosfomycin on Enterobacterales strains, given the poor performance of automated systems. The application of both automated systems, in the clinical laboratories reporting of fosfomycin, should be reviewed in light of the accuracy results falling below the acceptable threshold.

Activity of cefiderocol and synergy of novel β-lactam-β-lactamase inhibitor-based combinations against metallo-β-lactamase-producing gram-negative bacilli: insights from a two-year study (2019-2020)

This study was aimed at analyzing the prevalence of metallo-β-lactamase-producing Gram-negative bacilli (MBL-GNB) and evaluating both in vitro activity of cefiderocol and synergy of novel β-lactam-β-lactamase inhibitor-based combinations. Carbapenemase-producing Enterobacterales and meropenem-non-susceptible P. aeruginosa clinical strains were collected (2019-2020) and prevalence of MBL-producers investigated. Activity of cefiderocol was evaluated and synergistic effects of cefiderocol in combination with ceftazidime/avibactam vs aztreonam plus ceftazidime/avibactam vs meropenem/vaborbactam plus aztreonam were compared. Among carbapenemase-producing Enterobacterales, 87% (n = 307) produced KPC, 11.6% (n = 41) produced MBL, and 1.4% (n = 5) produced OXA-48-like. Among MBL-producing Enterobacterales, 78.1% (n = 32) and 21.9% (n = 9) were VIM- and NDM-producers, respectively. Among meropenem-non-susceptible P. aeruginosa, 1.9% (n = 8) produced VIM-type MBL. Cefiderocol resistance rate in VIM-producing Enterobacterales, VIM-producing P. aeruginosa, and NDM-producing Enterobacterales, was 6.2%, 12.5%, and 88.9%, respectively. Among MBL-producers tested, cefiderocol in combination with ceftazidime/avibactam showed a synergy rate of 20%, while for both aztreonam plus ceftazidime/avibactam and meropenem/vaborbactam plus aztreonam was 40%. Prevalence of MBL-producing Enterobacterales was remarkable. VIM-producing isolates were almost all susceptible to cefiderocol, while NDM-producers were often resistant. Meropenem/vaborbactam in combination with aztreonam showed similar synergistic activity to ceftazidime/avibactam plus aztreonam but the addition of aztreonam reduced MICs below the resistance breakpoint only for meropenem/vaborbactam.

Rapid diagnostics and ceftazidime/avibactam for KPC-producing Klebsiella pneumoniae bloodstream infections: impact on mortality and role of combination therapy

This study was aimed at investigating risk factors for mortality in patients suffering from KPC-producing Klebsiella pneumoniae (KPC-Kp) bloodstream infections (BSIs), evaluating the impact of rapid diagnostics and ceftazidime/avibactam use. This observational retrospective study (January 2017-May 2021) included all patients with a KPC-Kp BSI. Uni-multivariable analyses were carried out to evaluate the effect of clinical variables on both in-hospital death (IHD) and 30-day all-cause mortality, and the role of the combination of ceftazidime/avibactam plus polymyxin. One hundred and ninety-six patients met the study's inclusion criteria. Older age, having undergone renal replacement therapy during the 30 days preceding the KPC-Kp BSI onset, having an INCREMENT-CPE score ≥ 8, and having suffered from a superimposed and/or following KPC-Kp BSI treatment candidemia were found to be the main factors associated with both mortality rates. Among protective factors, the centrality of ceftazidime/avibactam in monotherapy (IHD: OR: 0.34; CI 95%: 0.11-1.00-30-day all-cause mortality: OR: 0.18; CI 95%: 0.04-0.77) or combination (IHD: OR: 0.51; CI 95%: 0.22-1.19-30-day all-cause mortality: OR: 0.62; CI 95%: 0.21-1.84) emerged and became even more evident once the effect of ceftazidime/avibactam plus polymyxin was removed. Rapid diagnostics may be useful to adopt more effective strategies for the treatment of KPC-Kp BSI patients and implement infection control measures, even if not associated with higher patient survival. Ceftazidime/avibactam, even when used alone, represents an important option against KPC-Kp, while combined use with polymyxin might not have altered its efficacy. Patient comorbidities, severity of BSI, and complications such as candidemia were confirmed to have a significant burden on survival.

Disc Diffusion and ComASP® Cefiderocol Microdilution Panel to Overcome the Challenge of Cefiderocol Susceptibility Testing in Clinical Laboratory Routine

Cefiderocol susceptibility testing represents a major challenge for clinical microbiology. Although disc diffusion showed robustness to test cefiderocol susceptibility, large areas of technical uncertainty (ATU) are reported by current EUCAST breakpoints. Herein, we evaluated the in vitro activity of cefiderocol on a collection of 286 difficult-to-treat Gram-negative isolates using disc diffusion and ComASP^® cefiderocol microdilution panel. Broth microdilution (BMD) in iron-depleted Mueller-Hinton broth was used as reference method. Following the EUCAST guidelines, disc diffusion allowed to determine cefiderocol susceptibility (susceptible or resistant) in 78.6%, 88.1%, 85.4% and 100% of Enterobacterales, P. aeruginosa, A. baumannii and S. maltophilia isolates tested, respectively. ComASP^® cefiderocol panel showed 94% and 84% of overall categorical agreement and essential agreement. Only one very major error and two major errors were observed, for MIC values nearly close to the resistance breakpoint (2 mg/L). Overall, 20.5% of the carbapenemase-producing Enterobacterales that achieved ATU results by the disc diffusion method tested resistant by both ComASP^® panel and reference BMD. Conversely, all VIM-producing P. aeruginosa showed MIC values in the susceptible range (≤2 mg/L). Lastly, only six out of seven (85.7%) A. baumannii isolates showing inhibition zones <17 mm tested resistant by both ComASP^® panel and the reference BMD suggesting that inhibition zone <17 mm are not unequivocally suggestive of resistance. Our results, although obtained on a limited number of isolates, suggest that the combination of disc diffusion with a ComASP^® cefiderocol microdilution panel could be a viable solution to overcome the challenge of cefiderocol susceptibility testing in routine microbiology laboratories.

Multicentre Surveillance of Candida Species from Blood Cultures during the SARS-CoV-2 Pandemic in Southern Europe (CANCoVEU Project)

Introduction: Surveillance of Candida species isolates from blood cultures (BCs) in Europe is considered fragmented, unable to allow the definition of targets of antifungal stewardship recommendations especially during the SARS-CoV-2 pandemic. Methods: We performed a multicentric retrospective study including all consecutive BC Candida isolates from six Southern European tertiary hospitals (1st January 2020 to 31st December 2021). Etiology, antifungal susceptibility patterns, and clinical setting were analyzed and compared. Results: C. albicans was the dominant species (45.1%), while C. auris was undetected. Candida species positive BC events increased significantly in COVID-19 ICUs in 2021 but decreased in other ICUs. Resistance to azole increased significantly and remained very high in C. albicans (fluconazole from 0.7% to 4.5%, p = 0.03) and C. parapsilosis complex (fluconazole up to 24.5% and voriconazole up to 8.9%), respectively. Resistance to caspofungin was remarkable in C. tropicalis (10%) and C. krusei (20%), while resistance to at least one echinocandin increased in 2021, especially in C. parapsilosis complex (from 0.8% to 5.1%, p = 0.05). Although no significant differences were observed over the study period, fluconazole and echinocandin resistance increased in COVID-19 ICUs by up to 14% and 5.8%, respectively, but remained undetected in non-intensive COVID-19 wards. Conclusions: Antifungal stewardship activities aimed at monitoring resistance to echinocandin in C. tropicalis and C. krusei, and against the spread of fluconazole resistant C. parapsilosis complex isolates are highly desirable. In COVID-19 patients, antifungal resistance was mostly present when the illness had a critical course.

Activity of ceftolozane-tazobactam, ceftazidime-avibactam, meropenem-vaborbactam, cefiderocol and comparators against Gram-negative organisms causing bloodstream infections in Northern Italy (2019-2021): emergence of complex resistance phenotypes

Herein we assessed the frequency of Gram-negative organisms causing bloodstream infections and activity spectrum of ceftolozane-tazobactam (CTZ), ceftazidime-avibactam (CZA), meropenem-vaborbactam (MEV), cefiderocol (CFDC) and comparators. Overall, 1605 Gram-negative isolates were consecutively collected during 2019-2021. Enterobacterales represented more than 75% and exhibited >90% susceptibility to CZA (97%), amikacin (91.8%) and meropenem (90.6%). ESBL-producing Enterobacterales isolates showed high rates of susceptibility towards CZA (100%), carbapenems (89.1-100%) and CTZ (84.9-95.1%). MEV displayed the highest activity against KPC-producing Enterobacterales (MIC50/90, 0.75/4 mg/L; 92.9% susceptible) followed by CZA (MIC50/90, ≤2/>8 mg/L; 89.3% susceptible), CFDC (MIC50/90, 0.25/4 mg/L, 87.5% susceptible) and colistin (MIC50/90, ≤2/4 mg/L, 83.9% susceptible). High proportions of P. aeruginosa isolates were susceptible to colistin (97.8%), CZA (97.2%), CTZ (96.1%) and amikacin (94.5%). CFDC showed potent activity against Acinetobacter baumannii (MIC50/90, 0.5/1 mg/L; 97.2% susceptible), multi-drug resistant P. aeruginosa (MIC50/90, 0.25/1 mg/L; 96% susceptible), and Stenotrophomonas maltophilia (MIC50/90, 0.12/0.25 mg/L; 100% susceptible).

Evaluation of a diagnostic algorithm for rapid identification of Gram-negative species and detection of extended-spectrum β-lactamase and carbapenemase directly from blood cultures

Objectives

To evaluate a rapid diagnostic algorithm based on MALDI-TOF MS, lateral flow immunoassays (LFIAs) and molecular testing performed directly from positive blood cultures (BCs) for Gram-negative species identification and detection of CTX-M extended-spectrum β-lactamases and main carbapenemases.

Methods

Non-duplicate BCs positive to Gram-negative bacteria at microscope examination were subjected to species identification by direct MALDI-TOF MS following recovery of bacterial pellet by Rapid MBT Sepsityper® kit. Subsequently, NG-Test® CARBA 5 and NG-Test® CTX-M MULTI LFIAs were performed according to identified microbial species. Eazyplex® SuperBug CRE molecular assay was performed in cases of NG-Test® CARBA 5 negative results in patients with documented carbapenemase-producers carriage. Results of rapid diagnostic workflow were compared with those obtained by conventional diagnostic routine.

Results

Overall, the direct MALDI-TOF MS protocol allowed reliable identification to the species level of 92.1% of the 2133 monomicrobial BCs. Rate of matched identification was significantly higher for Enterobacterales (97.3%) in comparison to non-fermenting Gram-negative species (80.2%), obligate anaerobic bacteria (42.1%) and fastidious Gram-negative species (41.5%). The overall sensitivity of NG-Test® CARBA 5 and NG-Test® CTX-M MULTI was 92.2% and 91.6%, respectively. Integration of Easyplex® SuperBug CRE allowed the detection of blaKPC mutants associated with ceftazidime/avibactam resistance, reaching 100% sensitivity in carbapenemase detection. Both LFIAs and molecular testing showed no false-positive results.

Conclusions

Algorithms based on MALDI-TOF MS, LFIAs and molecular testing may represent a cost-effective tool to timely identify Gram-negative species and detect resistance markers directly from BCs. According to local epidemiology, these results may allow antimicrobial stewardship interventions including prompt use of new approved drugs.

Rapid determination of ceftazidime/avibactam susceptibility of carbapenemase-producing Enterobacterales directly from blood cultures: a comparative evaluation of EUCAST disc diffusion RAST and direct Etest® RAST

OBJECTIVES

To evaluate the performance of two rapid antimicrobial susceptibility testing (RAST) methods to determine ceftazidime/avibactam susceptibility directly from blood cultures (BCs).

METHODS

A total of 246 Escherichia coli or Klebsiella pneumoniae isolates were tested for ceftazidime/avibactam susceptibility directly from BC bottles using EUCAST RAST and Etest® RAST. Results obtained after 4, 6 and 8 h of incubation were compared with those obtained by reference broth microdilution on pure overnight subcultures.

RESULTS

In total, the proportion of readable zones after 4 h of incubation was 96.7% and reached 100% after 6 and 8 h of incubation. EUCAST RAST yielded >98% of categorical agreement (CA) with all reading times. Major error (ME) and very major error (VME) rates were inferior to 3%, for each of the reading times. The proportion of results in the area of technical uncertainty (ATU) was almost similar (3.8%-4.1%) at the different reading times. DET-RAST yielded 97.5%, 98% and 99.6% of CA with readings at 4, 6 and 8 h, respectively. One (0.6%) ME was observed at each reading time, whereas five (5.9%) and four (4.5%) VMEs were observed analysing readings at 4 and 6 h, respectively. No VME was observed with readings at 8 h.

CONCLUSIONS

EUCAST RAST was accurate to determine ceftazidime/avibactam susceptibility of carbapenemase-producing K. pneumoniae and E. coli directly from BC bottles. DET-RAST has the advantage of determining MIC values and avoiding ATU results but showed to be an accurate method only with reading at 8 h.

Increased blaKPC Copy Number and OmpK35 and OmpK36 Porins Disruption Mediated Resistance to Imipenem/Relebactam and Meropenem/Vaborbactam in a KPC-Producing Klebsiella pneumoniae Clinical Isolate

Herein, we report the in vivo evolution of imipenem/relebactam-resistance in KPC-producing K. pneumoniae (KPC-Kp) isolated from a critically-ill patient treated with multiple combination therapies based on ceftazidime-avibactam or meropenem-vaborbactam. Imipenem/relebactam-resistance was associated to meropenem-vaborbactam cross-resistance and was due to truncated OmpK35 and OmpK36 porins and increased copy of blaKPC copy number. Genome analysis demonstrated that imipenem/relebactam-resistant KPC-Kp harbored a second copy of blaKPC-carrying Tn4401 in a ColRNAI plasmid as a consequence of a transposition event.

Occurrence of multi-carbapenemases producers among carbapenemase-producing Enterobacterales and in vitro activity of combinations including cefiderocol, ceftazidime-avibactam, meropenem-vaborbactam, and aztreonam in the COVID-19 era

PURPOSE

To evaluate the prevalence of multi-carbapenemase-producing Enterobacterales (EB) and the activity of cefiderocol (CFDC), meropenem-vaborbactam (MEV), ceftazidime-avibactam (CZA), and combinations of CZA plus aztreonam (ATM), MEV plus ATM and CFDC plus CZA against them.

METHODS

A collection of carbapenemase-producing EB clinical isolates (n = 1242) was investigated by lateral flow immunoassay NG-Test CARBA-5 and molecular testing. Cefiderocol MICs were determined using broth microdilution SensititreTM panel. MICs of CZA and MEV were determined by the gradient diffusion method. Antimicrobial synergy testing was performed using gradient diffusion strip crossing.

RESULTS

KPC were the most frequent carbapenemases (83.2%), followed by VIM (9.2 %), OXA-48-like (4.3 %) and NDM enzymes (4.1%). Multi-carbapenemase producers were found in 10 (0.8%) isolates. Three combinations of two different carbapenemases were observed: KPC+VIM (n = 4), NDM+OXA-48-like (n = 4), and VIM+OXA-48-like (n = 2). CFDC showed potent activity against eight out of ten dual-carbapenemases producers, while resistance or reduced susceptibility was shown towards CZA and MEV. CFDC in combination with CZA showed no synergistic effects and only two additive effects on seven (87.5%) of the CFDC-susceptible strains. Conversely, CZA plus ATM and MEV plus ATM combinations were synergistic against all ATM-resistant strains regardless of dual-carbapenemases phenotype.

CONCLUSIONS

The occurrence of multi-carbapenemase producers is not uncommon in Northern Italy area. MEV in combination with ATM might be considered as a potential therapeutic option, alternative to CZA plus ATM. CFDC susceptibility testing and synergy evaluation of ATM-based combinations should be performed in the lab routine to evaluate the most in vitro active antimicrobial regimen.

Trueperella bernardiae bloodstream infection following onco-gynaecologic surgery and literature review

Trueperella bernardiae is a Gram-positive commensal bacillus of the human skin and oropharynx. It is known as an opportunistic human pathogen causing surgical wound, skin, and soft tissue, osteoarticular, and bloodstream infections (BSIs) with severe complications. We report a case of surgical wound related T. bernardiae BSI following onco-gynaecologic surgery together with a comprehensive literature review of T. bernardiae infections to alert clinicians about this emerging pathogen.

In vitro activity of cefiderocol against ceftazidime-avibactam susceptible and resistant KPC-producing Enterobacterales: cross-resistance and synergistic effects

PURPOSE

To assess the in vitro activity of cefiderocol (CFDC) against a collection of both ceftazidime-avibactam (CZA) susceptible and resistant KPC-producing Enterobacterales (KPC-EB) isolates. Secondly, to assess its synergistic activity in combination with different antibiotics.

METHODS

One hundred KPC-EB isolates were tested: 60 CZA susceptible and 40 CZA resistant. Among them, 17 pairs of CZA susceptible and resistant KPC-producing Klebsiella pneumoniae (KPC-Kp) isolates were collected from 17 distinct patients before and after CZA treatment, respectively. CFDC susceptibility was evaluated by both broth microdilution (lyophilized panels; Sensititre; Thermo Fisher) and disk diffusion testing. Results were interpreted using EUCAST breakpoints. Synergistic activity of CFDC in combination with CZA, meropenem-vaborbactam, imipenem, and amikacin against six characterized KPC-Kp strains, before and after acquisition of CZA resistance, was evaluated using gradient diffusion strip crossing method.

RESULTS

CFDC resistance rate was significantly higher in CZA resistant EB subset than in the susceptible one (p < 0.001): 82.5% vs 6.7%. MIC50 and MIC90 values were 0.25 and 2 mg/L, 8 and 64 mg/L in CZA-susceptible and CZA-resistant subset, respectively. KPC-Kp isolates harboring KPC-D179Y or KPC-Δ242-GT-243 variants showed CFDC MICs ranging from 4 to 64 mg/L. CFDC showed in vitro synergistic effect mostly with CZA, against both CZA susceptible and resistant isolates, resulting in a synergy rate of 66.7%.

CONCLUSIONS

CZA resistance mechanisms in KPC-EB impair the in vitro activity of CFDC, often leading to co-resistance. CFDC in combination with the new β-lactamases inhibitors might represent a strategy to enhance its activity.

Burden of primary influenza and respiratory syncytial virus pneumonia in hospitalized adults: insights from a two-year multi-centre cohort study (2017-2018)

This two-year (2017-2018) multi-centre study on 356 adults hospitalized for influenza A/B and RSV pneumonia analysed factors associated with non-invasive ventilation (NIV) failure and in-hospital death (IHD.) Patients with both obstructive sleep apnoea or obesity hypoventilation syndrome and influenza-A virus pneumonia showed a higher risk for NIV failure (OR 4.66; 95% CI 1.42-15.30). Patients submitted to NIV showed a higher risk for IHD, regardless of comorbidities (influenza-A OR 3.00; 95% CI 1.35-6.65, influenza-B OR 4.52; 95% CI 1.13-18.01, RSV OR 5.61; 95% CI 1.26-24.93). The increased knowledge of influenza-A/B and RSV pneumonia burden may contribute to a better management of patients with viral pneumonia. This article is protected by copyright. All rights reserved.

Exposure to the agricultural fungicide tebuconazole promotes Aspergillus fumigatus cross-resistance to clinical azoles

Resistance to clinical triazoles in Aspergillus fumigatus is a growing concern for individuals at high risk of Aspergillus infection. Two triazole resistance selection routes are currently being investigated: one occurring in triazole-treated patients in healthcare settings, and the second taking place in the environment due to the widespread use of agricultural triazoles. This study aimed to assess the ability of agricultural azoles to promote cross-resistance to clinical azoles in A. fumigatus. Five A. fumigatus isolates susceptible to clinical azoles were exposed to the triazole 14α-demethylase inhibitor, tebuconazole (TBC), and then antifungal susceptibility tests for voriconazole, itraconazole, posaconazole and isavuconazole were performed. Under TBC selection pressure, all A. fumigatus isolates exhibited resistance to clinical triazoles. However, only two displayed a multiresistant phenotype to clinical azoles. TBC exposure was also associated with delayed conidia formation and progressive absence of conidiation. Noteworthy, no TBC-exposed clones harbored TR34/L98H mutation, as judged by real-time PCR assays. The observation that TBC exposure promotes cross-resistance to clinical triazoles warrants careful and thorough assessment of the human health risk associated with agricultural azoles. The absence of TR34/L98H mutation in cross-resistant A. fumigatus isolates suggests that other cyp51A mutations may be involved in clinical azole cross-resistance.

Evaluation of an antigen-based test for hospital point-of-care diagnosis of SARS-CoV-2 infection

Background

An accurate diagnosis is essential to identify and manage SARS-CoV-2 infected patients and implement infection control measures. Although real-time reverse transcription polymerase chain reaction (RT-PCR) is the current recommended laboratory method, several rapid antigen point-of-care tests (POCTs) were developed as frontline testing for SARS-CoV-2 infection diagnosis.

Objectives

The aim of this study was to assess a recently CE-approved POCT, SARS-CoV-2 Ag Test on the LumiraDx™ Platform (LumiraDx GmbH, Cologne, Germany) for the identification of SARS-COV-2 infected subjects at hospital setting.

Methods

LumiraDx POCT was implemented in three hospital settings: adult and pediatric emergency departments and occupational medicine department along two-month period during the second peak of Italian SARS-CoV-2 pandemic. Rapid antigen testing was performed on direct nasal swabs and results were compared with those obtained by Xpert Xpress SARS-CoV-2 assay.

Results

Overall sensitivity, specificity, NPV and PPV were 90.3%, 92.1%, 95.1%, and 84.9%, respectively, compared to reference method. Sensitivity, specificity, PPV and NPV for symptomatic group were 89.3% [95% IC 84.2-93.3], 88.2% [95% IC 72.5-96.7], 97.8% [95% IC 94.6-99.1], and 58.8% [95% IC 48.4-68.5], respectively. Sensitivity, specificity, PPV and NPV for asymptomatic group were 92.1% [95% IC 85-96.5], 92.3% [95% IC 89.9-94.4], 67.9% [95% IC 61.3-73.8], and 98.5% [95% IC 97.1-99.2], respectively. False positive and negative antigen testing results in both symptomatic and asymptomatic group were observed.

Conclusion

SARS-CoV-2 Ag POCT may represent an interesting tool to rapidly identify symptomatic or asymptomatic infected subjects. However, in hospital setting in which false negative or false positive results may have relevant implications, confirmatory NAAT always remains necessary for the appropriate management of patients.

Severity of RSV infection in Southern European elderly patients during two consecutive winter seasons (2017-2018)

In Europe, the respiratory syncytial virus (RSV) surveillance system is very heterogeneous and there is growing evidence of the importance of RSV infections resulting in hospitalization of elderly patients. The aim of this study was to assess the severity of RSV infection in the elderly living in the aged Southern European countries. We conducted a retrospective study of elderly patients ( ≥65‐year old) admitted for laboratory‐confirmed RSV infection in three tertiary hospitals in Portugal, Italy, and Cyprus over two consecutive winter seasons (2017–2018). Uni‐multivariable analyses were carried out to evaluate the effect of clinical variables on radiologically confirmed pneumonia, use of noninvasive ventilation (NIV), and in‐hospital death (IHD). A total of 166 elderly patients were included. Pneumonia was evident in 29.5%. NIV was implemented in 16.3%, length of stay was 11.8 ± 12.2 days, and IHD occurred in 12.1%. Multivariable analyses revealed that the risk of pneumonia was higher in patients with chronic kidney disease (CKD) (odds ratio [OR]: 2.57; 95% confidence interval [CI]: 1.12–5.91); the use of NIV was higher in patients with obstructive sleep apnea or obesity hypoventilation syndrome (OSA or OHS) (OR: 5.38; 95% CI: 1.67–17.35) and CKD (OR: 2.52; 95% CI: 1.01–6.23); the risk of IHD was higher in males (OR: 3.30; 95% CI: 1.07–10.10) and in patients with solid neoplasm (OR: 9.06; 95% CI: 2.44–33.54) and OSA or OHS (OR: 8.39; 95% CI: 2.14–32.89). Knowledge of factors associated with RSV infection severity may aid clinicians to set priorities and reduce disease burden. Development of effective antiviral treatment and vaccine against RSV is highly desirable.

Acute liver failure due to radiographically occult infiltration of urothelial cancer

Introduction

Acute liver failure (ALF) due to diffuse infiltrating solid malignancy without any focal lesions on radiographic imaging is rare.

Case report

A 70-year-old man was admitted due to mental confusion, abdominal pain, and ALF. Three years before, he had undergone a left nephrectomy for urothelial carcinoma followed by adjuvant chemotherapy. The abdominal computed tomography (CT) showed hepatomegaly and ascites. Ascitic fluid had transudate characteristics, with no malignant cells. Percutaneous liver biopsy (LB) showed diffuse liver infiltration of metastatic urothelial carcinoma. The patient rapidly deteriorated and died in a week due to ALF.

Discussion

History of solid cancer and hepatomegaly and/or liver failure without other obvious explanation should encourage to perform LB.

Conclusion

LB is warranted to avoid misdiagnosis, prolonged hospital stays, and delay in palliative care.

Fast-track identification of CTX-M-extended-spectrum-β-lactamase- and carbapenemase-producing Enterobacterales in bloodstream infections: implications on the likelihood of deduction of antibiotic susceptibility in emergency and internal medicine departments

This study aims at presenting a reliable fast-track diagnostics for the detection of CTX-M ESBL- (CTX-M-p) and carbapenemase-producers (CA-p) directly from blood cultures (BCs) of patients with Enterobacterales (EB) bloodstream infections (BSIs) admitted in emergency and internal medicine departments and its contribution in estimation of in vitro antibiotic susceptibility. A fast-track workflow including MALDI-TOF species identification and two lateral flow immunochromatographic assays for the detection of CTX-M-p and CA-p directly from BCs was performed in parallel with conventional routine, and results were compared. A total of 236 BCs of patients suffering from EB BSI were included. Accuracy of the fast-track workflow ranged from 99.6 to 100%. Among E. coli isolates, CTX-M-p (20.5%) were susceptible to ceftolozane-tazobactam (C/T, 97%), ceftazidime-avibactam (CZA, 100%), and piperacillin-tazobactam (TZP, 84.8%), whereas CTX-M-and-main-carbapenemases-non-producer (CTX-M-CA-np, 79.5%) isolates were susceptible to all the antibiotics tested. Among K. pneumoniae isolates, CTX-M-p (23.3%) were poorly susceptible to TZP (40%) but widely susceptible to C/T (90%), CZA (100%), and amikacin (90%), whereas CTX-M-CA-np (55.8%) were also susceptible to cefepime. CA-p K. pneumoniae (20.9%) were susceptible to CZA (88.9%). All the species other than E. coli and K. pneumoniae were CTX-M-CA-np and were widely susceptible to the antibiotics tested except for isolates of the inducible and derepressed AmpC- or AmpC/ESBL-p species. Rapid identification of species and phenotype together with knowledge of local epidemiology may be crucial to determine the likelihood of deduction of in vitro antibiotic susceptibility on the same day of positive BC processing.

Ceftazidime-avibactam resistance and restoration of carbapenem susceptibility in KPC-producing Klebsiella pneumoniae infections: A case series

OBJECTIVES

Since the introduction of the β-lactam/β-lactamase inhibitor ceftazidime-avibactam (CZA), rapid evolution of resistance has been reported in different KPC-producing Klebsiella pneumoniae isolates. In this multicenter retrospective study, we describe the emergence of CZA resistance and evaluate the mutations that might be responsible for the restoration of carbapenem susceptibility.

METHODS

During a study period of 18 months, KPC-producing K. pneumoniae isolates of five hospitalized patients were collected with phenotypic development of CZA resistance.

RESULTS

In vitro restoration of carbapenem susceptibility during treatment was observed in 3 isolates. Whole genome sequencing of these isolates showed a D179Y mutation in the KPC gene of 2 variants and a KPC-2 with a Δ242-GT-243 deletion (KPC-14). Two KPC-3 variants showed CZA resistance with sustained carbapenemase activity without genomic adaptations in the KPC gene.

CONCLUSIONS

This study confirms the emergence of CZA resistance in KPC K. pneumoniae. The role of carbapenems in treating patients with these variants is unclear and combination therapies warrant further investigation.

Direct Ethylenediaminetetraaceticacid-Modified β-Lactam Inactivation Method: An Improved Method to Identify Serine-Carbapenemase-, Metallo-β-Lactamase-, and Extended-Spectrum-β-Lactamase-Producing Enterobacterales Directly from Positive Blood Culture

Rapid identification of extended-spectrum-β-lactamase (ESBL)-, serine carbapenemase-, and metallo-β-lactamase (MBL)-producing Enterobacterales directly from positive blood culture (BC) bottles is of paramount importance to early optimize antimicrobial management and infection control measures. In this study, we describe and evaluate an improved variant of direct β-lactam inactivation method, named direct ethylenediaminetetraaceticacid-modified-β-lactam inactivation method (deBLIM). The deBLIM test is designed to detect ESBL or carbapenemase activity and to differentiate serine-carbapenemases from MBLs directly from Enterobacterale-positive BCs. The deBLIM was evaluated on both aerobic and anaerobic BCs spiked with 167 characterized Enterobacterale isolates. The deBLIM showed 100% sensitivity in detecting KPC and OXA-48-like serine carbapenemase, CTX-M, SHV variants, and TEM-10 ESBLs both in aerobic and anaerobic conditions. In contrast, a significant discrepancy between aerobic and anaerobic BCs was observed in detecting MBLs. The sensitivity rate in aerobic BCs was of 100% for all metalloenzyme types, whereas only 56.1% and 80% of VIM and NDM producers were detected in anaerobic bottles, respectively. IMP-producing Escherichia coli NCTC 13476 was also not detected in the anaerobic BC. No false positive result was observed among ESBL producers and broad-spectrum-β-lactamase nonproducers, demonstrating an overall specificity of 100%. The deBLIM could be a cost-effective screening method for the identification of ESBLs, serine carbapenemases, and MBLs directly from Enterobacterale-positive BCs on the same day of bottle positivity detection. Nevertheless, it must be considered its poor performance in detecting MBLs in the anaerobic condition.

Detection of Carbapenemase and CTX-M Encoding Genes Directly from Bronchoalveolar Lavage Using the CRE and ESBL ELITe MGB Assays: Toward Early and Optimal Antibiotic Therapy Management of Critically Ill Patients with Pneumonia

The detection of carbapenemase extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (EB) has become a major issue among critically ill patients, especially due to their impact on appropriate antimicrobial therapy. This study aimed at evaluating the potential contribution of molecular assays to early optimization of empirical antibiotic therapy among critically ill patients with carbapenemase- and/or CTX-M-producing EB pneumonia. The CRE and ESBL ELITe MGB^® assays were evaluated directly on 197 bronchoalveolar lavage (BAL) samples obtained from 120 patients. Molecular results were then compared to routine culture-based diagnostic results, and a retrospective analysis of the therapeutic antimicrobial management was performed. Among the 197 clinical specimens, bla_KPC-like and bla_CTX-M-like were detected in 20 (10.2%) and 12 (6.1%) specimens belonging to 15 and 11 patients, respectively. Positive predictive value (PPV) and negative predictive value (NPV) of the CRE ELITe MGB Kit were 85% [95% confidence interval [CI]: 64.9-94.6] and 100%, respectively. PPV and NPV of the ESBL ELITe MGB Kit were 75% [95% CI: 49.4-90.2] and 100%, respectively. Retrospective analysis of the therapeutic antimicrobial management at the time of BAL collection showed that in ∼50% of patients with carbapenemase- and CTX-M-producing EB pneumonia empirical antibiotic therapy could have been optimized at least 48-72 hr earlier if positive molecular data had been used. The CRE and ESBL ELITe MGB assays might be an interesting tool for expediting optimization of empirical antibiotic therapy in critically ill patients with pneumonia, depending on local epidemiology of antibiotic resistance, patient risk stratification for EB infection, and availability of an antimicrobial stewardship team.

Influenza and respiratory syncytial virus infections in the oldest-old continent

SARS-CoV-2 dramatically revealed the sudden impact of respiratory viruses in our lives. Influenza and respiratory syncytial virus (RSV) infections are associated with high rates of morbidity, mortality, and an important burden on healthcare systems worldwide, especially in elderly patients. The aim of this study was to identify severity predictors in the oldest-old admitted with influenza and/or RSV infections. This is a multicenter, retrospective study of all oldest-old patients (≥ 85 years old) admitted for laboratory-confirmed influenza and/or RSV infection in three tertiary hospitals in Portugal, Italy, and Cyprus over two consecutive winter seasons. The outcomes included the following: pneumonia on infection presentation, use of non-invasive ventilation (NIV), and in-hospital death (IHD). The association with possible predictors, including clinical features and type of virus infection, was assessed using uni- and multivariable analyses. A total of 251 oldest-old patients were included in the study. Pneumonia was evident in 32.3% (n = 81). NIV was implemented in 8.8% (n = 22), and IHD occurred in 13.9% (n = 35). Multivariable analyses revealed that chronic obstructive pulmonary disease (COPD) or asthma was associated with pneumonia (OR 1.86; 95% CI 1.02-3.43; p = 0.045). COPD or asthma (OR 4.4; 95% CI 1.67-11.6; p = 0.003), RSV (OR 3.12; 95% CI 1.09-8.92; p = 0.023), and influenza B infections (OR 3.77; 95% CI 1.06-13.5; p = 0.041) were associated with NIV use, respectively, while chronic kidney disease was associated with IHD (OR 2.50; 95% CI 1.14-5.51; p = 0.023). Among the oldest-old, chronic organ failure, such as COPD or asthma, and CKD predicted pneumonia and IHD, respectively, beyond the importance of viral virulence itself. These findings could impact on public health policies, such as fostering influenza immunization campaigns, home-based care programs, and end-of-life care. Filling knowledge gaps is crucial to set priorities and advise on transition model of care that best fits the oldest-old.

RESIST-5 O.O.K.N.V. and NG-Test Carba 5 assays for the rapid detection of carbapenemase-producing Enterobacterales from positive blood cultures: a comparative study

We prospectively compared the performance of RESIST-5 O.O.K.N.V. and NG-Test Carba 5 assays directly from blood cultures spiked with 130 characterized Enterobacterales isolates. Overall, both assays yielded 100% sensitivity to detect KPC-type carbapenemases and OXA-48-like carbapenemases. Both assays failed to detect KPC-31 and KPC-33, D179Y point mutation variants of KPC-3 and KPC-2, that are deprived of carbapenemase activity and confer resistance to ceftazidime-avibactam. On blood culture bacterial pellets, NDM- and VIM-type carbapenemases were detected in 50.0% and 52.2%, respectively, by RESIST-5 O.O.K.N.V. vs 100% by NG-Test Carba 5. The sensitivity of RESIST-5 O.O.K.N.V. improved to 100% and 95.6%, respectively, by performing the assay on 4-h early subculture.

Recurrent Klebsiella pneumoniae Infection Causing Transcatheter Aortic Valve Implantation (TAVI)-Related Endocarditis

The authors report the case of an 86-year-old woman presenting with recurrent Klebsiella pneumoniae bacteraemia. She had severe aortic stenosis submitted to a recent transcatheter aortic valve implantation (TAVI). Initially, Klebsiella pneumoniae bacteraemia from a urinary source was diagnosed. Following another 4 episodes of bacteraemia with the same agent, the source was ultimately found to be a periprosthetic abscess. Considering the patient’s unsuitability for surgery, a decision was made for life-long antimicrobial therapy. This approach has been successful in preventing recurrences or complications. Endocarditis is one of the most severe complications seen following TAVI, often carrying a poor prognosis. Even though Klebsiella spp. are common pathogens for healthcare-associated infections among the elderly, they are seldom the causative agent for endocarditis. Being the first reported case of TAVI-related Klebsiella endocarditis, it was successfully managed using a medical approach.

Accuracy of the ELITe MGB assays for the detection of carbapenemases, CTX-M, Staphylococcus aureus and mecA/C genes directly from respiratory samples

INTRODUCTION

Bacterial lower respiratory tract infections (BLRTI) may represent serious clinical conditions which can lead to respiratory failure, intensive care unit admission and high hospital costs. The detection of carbapenemase- and extended-spectrum β-lactamase (ESBL)-producing Enterobacterales, as well as meticillin-resistant Staphylococcus aureus (MRSA), has become a major issue, especially in healthcare-associated infections. This study aimed to determine whether molecular assays could detect genes encoding carbapenemases, ESBL and MRSA directly from respiratory samples in order to expedite appropriate therapy and infection control for patients with BLRTI.

METHODS

The carbapenem-resistant enterobacterales (CRE), ESBL and MRSA/SA ELITe MGB assays were performed directly on 354 respiratory specimens sampled from 318 patients admitted with BLRTI. Molecular results were compared with routine culture-based diagnostics results.

RESULTS

Positive (PPV) and negative (NPV) predictive values of the CRE ELITe MGB kit were 75.9% [95% confidence interval (CI) 60.3-86.7] and 100%, respectively. PPV and NPV of the ESBL ELITe MGB kit were 80.8% (95% CI 63.6-91.0) and 99.1% (95% CI 96.6-99.8), respectively. PPV and NPV of the MRSA/SA ELITe MGB kit were 91.7% (95% CI 73.7-97.7)/100% and 98.3% (95% CI 89.8-99.3)/96.8% (95% CI 81.6-99.5), respectively.

DISCUSSION

Validity assessment of molecular assays detecting the main antibiotic resistance genes directly from respiratory samples showed high accuracy compared with culture-based results. Molecular assays detecting the main carbapenemase, ESBL, S. aureus and meticillin resistance encoding genes provide an interesting tool with potential to expedite optimization of antibiotic therapy and infection control practices in patients with BLRTI.

Bacterial etiology and antimicrobial resistance trends in ocular infections: A 30-year study, Turin area, Italy

PURPOSE

Bacterial ocular infections can result in loss of all or part of the ocular structures, contributing to a high disability charge. Local surveillance of etiology and susceptibility patterns is crucial for an appropriate empiric management of ocular infections. The aim of this study was to analyze of bacterial spectrum in culture-proven ocular infections and trends of antimicrobial susceptibility patterns.

METHODS

A monocentric retrospective study was performed including ocular infection cases diagnosed at the Microbiology Unit of Turin Ophthalmic Hospital between 1988 and 2017. Spectrum of pathogens that caused bacterial culture-proven ocular infections and trends of antimicrobial susceptibility patterns were analyzed.

RESULTS

A total of 15,517 culture-positive isolates were identified as causative agents of ocular infections. Gram-positive bacteria were deemed to cause infection in 73.5% of cases. Staphylococcus spp. and Pseudomonas spp., coagulase-negative staphylococci, Staphylococcus aureus were the leading causative pathogens of keratitis, endophthalmitis, and conjunctivitis, respectively. Statistically significant changes in temporal trends were observed for all analyzed microorganism groups except for Enterobacteriaceae group. Overall, fluoroquinolones and chloramphenicol demonstrated to be the most effective antimicrobials in vitro toward bacterial ocular infections, followed by tetracycline, ampicillin, and aminoglycosides. Enterobacteriaceae isolates showed higher multi-drug resistance rate, followed by coagulase-negative staphylococci. Analysis of resistance rates over time highlighted increasing resistance trend for aminoglycosides among Gram-negative and for both aminoglycosides and fluoroquinolones among Gram-positive pathogens, especially for S. aureus.

CONCLUSION

This study provided a 30-year assessment of bacterial ocular infections in an urban area of Italy, giving support to epidemiological consciousness and guiding empiric antimicrobial therapy.

Rubella serosurvey and factors related to vaccine hesitancy in childbearing women in Italy

Voluntary termination of pregnancy (VTP), pre-conception and post-partum phases, as well as Occupational Medicine consultation for healthcare workers are opportunities for screening and vaccinating rubella seronegative childbearing women. However, data about vaccination acceptance following these phases is rarely reported. A retrospective study over a 2-year period (2016-2017) was performed, evaluating the prevalence of rubella seronegative women which underwent VTP (wVTP), mothers in early puerperal phase (mEPP) and childbearing healthcare workers (CbHW) aged 15-49 years. Anti-rubella vaccination rates and factors associated with vaccine hesitancy (VH) were investigated. Anti-rubella IgG titres were assessed in 8623 women. Seroprevalence of rubella susceptibility was 7.9% (wVTP 6.4%; mEPP 17.4%; CbHW 9.3%). Anti-rubella vaccination rates were found to be different in the three groups (wVTP 37.1%; mEPP 10.9%; CbHW 25.4%), specifically in 2016 and among women born in Italy. VH rate was higher in 2017, especially among wVTP and CbHW. Anti-rubella vaccination rates in wVTP vs. mEPP was higher in women born in Italy but not in those born abroad. Multivariable analyses demonstrated significantly higher risk of VH for mEPP (OR 8.2; 95% CI: 3.9-16.9) and women reporting history of allergy to drugs, food or environmental agents (OR 2.7; 95% CI: 1.4-5.1). During the analyzed period childbearing women included in this study were not adequately protected against rubella. Anti-rubella vaccination rates were widely unsatisfactory. Being mEPP and reporting allergy were significantly associated to higher rates of VH. Tailored strategies targeting on vaccine safety are needed for retention of these women in immunisation programmes.

Ralstonia mannitolilytica bacteraemia: a case report and literature review

Ralstonia mannitolilytica is a difficult-to-diagnose, aerobic, Gram-negative bacillus, mainly causing healthcare infections in immunocompromised hosts. We report the first case of R. mannitolilytica bacteraemia in a kidney transplant recipient. Identification of R. mannitolilytica was finally performed by 16S rRNA gene sequencing. All cases of R. mannitolilytica bacteraemia reported in the English language literature over the past 20 years are reviewed to alert clinicians to the epidemiological, clinical, diagnostic, prognostic and microbiologic features of this emerging pathogen.

Pasteurella infections in a tertiary centre - from cellulitis to multiple-organ failure: Retrospective case series

The purpose of this article is to review the clinical features of pasteurellosis in a tertiary centre over a period of 4½ years. We have identified eight cases of Pasteurella multocida and one case of Pasteurella canis infection, with a large diversity of clinical pictures and outcomes. All patients were elderly and/or immunocompromised and 55.6% reported animal exposure. Soft tissue infections were the most prevalent (55.6%), followed by pneumonia (22.2%) and sepsis (22.2 %). All isolates were susceptible to beta-lactam antibiotics using in vitro sensitivity testing. The overall mortality was 33.3%, which occurred in patients with no evidence of animal contact.

Infections on the rise: Raoultella spp., clinical and microbiological findings from a retrospective study, 2010-2014

We performed a retrospective analysis of clinical and laboratory data over 5 years in a tertiary centre to assess clinical and microbiological characteristics of patients with Raoultella spp. infection. Raoultella spp. were deemed responsible for clinical infections in 57 patients (R. planticola, n = 32 and R. ornithinolytica, n = 25). The most prevalent diagnoses for R. planticola were cystitis (50%; n = 16) followed by bacteraemia and pneumonia (9.4%; n = 3); for R. ornithinolytica, cystitis (36%; n = 9) followed by pneumonia (24%; n = 6). Immunodeficiency was present in 18 patients (56.3%) with R. planticola and in 16 patients (64%) with R. ornithinolytica infection. Of these, 55.6% and 37.5% had diabetes and 27.8% and 18.% were solid organ transplant recipients, respectively. All isolates were sensitive to third-generation cephalosporins, fluoroquinolones and aminoglycosides. Mortality of infections with R. planticola (n = 5; 15.6%) was higher than for R. ornithinolytica (n = 2; 8.0%), but the difference was not statistically significant.

The impact of the Lisbon Football Derby on the profile of emergency department admissions

BACKGROUND

Variations in emergency department admissions have been reported to happen as a result of major sports events. The work presented assessed changes in volume and urgency level of visits to a major Emergency Department in Lisbon during and after the city's football derby.

MATERIAL AND METHODS

Volume of attendances and patient urgency level, according to the Manchester Triage System, were retrospectively analyzed for the 2008-2011 period. Data regarding 24-hour periods starting 45 minutes before kick-off was collected, along with data from similar periods on the corresponding weekdays in the previous years, to be used as controls. Data samples were organized according to time frame (during and after the match), urgency level, and paired accordingly.

RESULTS

A total of 14 relevant periods (7 match and 7 non-match) were analyzed, corresponding to a total of 5861 admissions. During the match time frame, a 20.6% reduction (p = 0.06) in the total number of attendances was found when compared to non-match days. MTS urgency level sub-analysis only showed a statistically significant reduction (26.5%; p = 0.05) in less urgent admissions (triage levels green-blue). Compared to controls, post-match time frames showed a global increase in admissions (5.6%; p = 0.45), significant only when considering less urgent ones (18.9%; p = 0.05).

DISCUSSION

A decrease in the total number of emergency department attendances occurred during the matches, followed by a subsequent increase in the following hours. These variations only reached significance among visits triaged green-blue.

CONCLUSION

During major sports events an overall decrease in emergency department admissions seems to take place, especially due to a drop in visits associated with less severe conditions.