In Vivo Evolution of GES ß-Lactamases Driven by Ceftazidime/Avibactam Treatment of Pseudomonas aeruginosa Infections.

The mechanisms underlying an in vivo switch in the resistance phenotype of P. aeruginosa after ceftazidime-avibactam treatment was investigated. The initial isolate (a blood culture) was resistant to meropenem but remained susceptible to antipseudomonal cephalosporins and combinations with ß-lactamase inhibitors. One week after ceftazidime-avibactam therapy, a subsequent isolate (a rectal swab) recovered from the same patient showed the opposite phenotype. Whole-genome sequence analysis revealed a single SNP difference between both (ST235) isolates, leading to a P162S change in blaGES-5, creating blaGES-15. Thus, blaGES-1, blaGES-5, and blaGES-15 were cloned and expressed in the wild-type strain PAO1. Susceptibility profiles confirmed the P162S substitution reverted the carbapenemase phenotype determined by the G170S change of GES-5 back into the ESBL phenotype of GES-1.

Clinical features and disease progression of elderly patients at the ICU setting.

OBJECTIVE: To describe and characterize a cohort of octogenarian patients admitted to the ICU of the University Central Hospital of Asturias (HUCA). DESIGN: Retrospective, observational and descriptive study of 14 months' duration. SETTING: Cardiac and Medical intensive care units (ICU) of the HUCA (Oviedo). PARTICIPANTS: Patients over 80 years old who were admitted to the ICU for more than 24 h. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: Age, sex, comorbidity, functional dependence, treatment, complications, evolution, mortality. RESULTS: The most frequent reasons for admission were cardiac surgery and pneumonia. The average admission stay was significantly longer in patients under 85 years of age (p = 0,037). 84,3% of the latter benefited from invasive mechanical ventilation compared to 46,2% of older patients (p = <0,001). Patients over 85 years of age presented greater fragility. Admission for cardiac surgery was associated with a lower risk of mortality (HR = 0,18; 95% CI (0,062-0,527; p = 0,002). CONCLUSIONS: The results have shown an association between the reason for admission to the ICU and the risk of mortality in octogenarian patients. Cardiac surgery was associated with a better prognosis compared to medical pathology, where pneumonia was associated with a higher risk of mortality. Furthermore, a significant positive association was observed between age and frailty.

Nosocomial Pneumonia Caused in an Immunocompetent Patient by the Emergent Monophasic ST34 Variant of Salmonella enterica Serovar Typhimurium: Treatment-Associated Selection of Fluoroquinolone and Piperacillin/Tazobactam Resistance.

The present report describes an uncommon case of nosocomial pneumonia caused by Salmonellaenterica in an immunocompetent patient. The patient was admitted to ICU of a tertiary hospital due to low level of consciousness, aphasia and seizure episodes. Four days after hospitalization, he developed nosocomial pneumonia, which evolved into septic shock. Gram-negative bacilli were recovered from blood, tracheal aspirate and fecal samples of the patient. The isolates, which were identified as Salmonella enterica, proved to be resistant to ciprofloxacin, amoxicillin/clavulanic acid and piperacillin/tazobactam. Four months before, the same bacterial species was recovered from feces and blood cultures of the patient, admitted to the nephrology ward of the same hospital with diagnosis of gastroenteritis and acute renal failure. However, at that time, the isolates were susceptible to the above-mentioned antibiotics. Genome sequencing revealed that all isolates were closely related and belonged to the emergent ST34 monophasic variant of S. enterica serovar Typhimurium. Since the patient has received therapy with fluoroquinolones and amoxicillin/clavulanic acid, these results support treatment-associated selection of the acquired resistances. In conclusion, this case represents a paradigm of selective pressure leading to in vivo development of resistance to highly relevant antibiotics, including the piperacillin/tazobactam combination used for empirical management of severe infections at ICU.

Evaluation and Clinical Impact of Biofire FilmArray Pneumonia Panel Plus in ICU-Hospitalized COVID-19 Patients.

Microbiological diagnosis by using commercial multiplex quantitative PCR systems provides great advantages over the conventional culture. In this work, the Biofire FilmArray Pneumonia Panel Plus (FAPP+) was used to test 144 low respiratory tract samples from 105 COVID-19 patients admitted to an Intensive Care Unit (ICU), detecting 78 pathogens in 59 (41%) samples. The molecular panel was evaluated by using the conventional culture (CC) as comparator, which isolated 42 pathogens in 40 (27.7%) samples. The overall percentage of agreement was 82.6%. Values of sensitivity (93%), specificity (62%), positive predictive value (50%), and negative predictive value (96%) were obtained. The mean time elapsed from sample extraction to modification of antibiotic treatment was 7.6 h. A change in antimicrobial treatment after the FAPP+ results was performed in 27% of patients. The FAPP+ is a highly sensitive diagnostic method that can be used to significantly reduce diagnostic time and that allows an early optimization of antimicrobial treatment.

Spread of OXA-48-producing Klebsiella pneumoniae among COVID-19-infected patients: The storm after the storm.

The impact of secondary infections by multidrug-resistant bacteria in COVID-19- infected patients has yet to be evaluated. Here, we report the clinical and molecular features of an outbreak of seven patients carrying CTX-M-15- and OXA-48-producing Klebsiella pneumoniae belonging to ST326 during COVID-19 pandemic in an ICU in northern Spain. Those patients were admitted to beds close to each other, two of them developed ventilator-associated pneumonia (VAP), one exhibited primary bacteremia and the remaining four were considered to be colonized. None of them was colonized prior to admission to the ICU an all, except one of those who developed VAP, were discharged. Hydroxychloroquine and lopinavir/ritonavir were administered to all of them as COVID-19 therapy and additionally, three of them received tocilizumab and corticosteroids, respectively. Reusing of personal protective equipment due to its initial shortage, relaxation in infection control measures and negative-pressure air in ICU rooms recommended for the protection of health care workers (HCWs), could have contributed to this outbreak. Maximization of infection control measures is essential to avoid secondary infections by MDR bacteria in COVID-infected patients.

SARS-CoV-2 analysis on environmental surfaces collected in an intensive care unit: keeping Ernest Shackleton's spirit.

BACKGROUND: Intensive care unit workers are at high risk of acquiring COVID-19 infection, especially when performing invasive techniques and certain procedures that generate aerosols (< 5 µm). Therefore, one of the objectives of the health systems should implement safety practices to minimize the risk of contagion among these health professionals. Monitoring environmental contamination of SARS-CoV-2 may help to determine the potential of the environment as a transmission medium in an area highly exposed to SARS-CoV-2, such as an intensive care unit. The objective of the study was to analyze the environmental contamination by SARS-CoV-2 on surfaces collected in an intensive care unit, which is dedicated exclusively to the care of patients with COVID-19 and equipped with negative pressure of - 10 Pa and an air change rate of 20 cycles per hour. Furthermore, all ICU workers were tested for COVID-19 by quantitative RT-PCR and ELISA methods. RESULTS: A total of 102 samples (72 collected with pre-moistened swabs used for collection of nasopharyngeal exudates and 30 with moistened wipes used in the environmental microbiological control of the food industry) were obtained from ventilators, monitors, perfusion pumps, bed rails, lab benches, containers of personal protective equipment, computer keyboards and mice, telephones, workers' shoes, floor, and other areas of close contact with COVID-19 patients and healthcare professionals who cared for them. The analysis by quantitative RT-PCR showed no detection of SARS-CoV-2 genome in environmental samples collected by any of the two methods described. Furthermore, none of the 237 ICU workers was infected by the virus. CONCLUSIONS: Presence of SARS-CoV-2 on the ICU surfaces could not be determined supporting that a strict cleaning protocol with sodium hypochlorite, a high air change rate, and a negative pressure in the ICU are effective in preventing environmental contamination. These facts together with the protection measures used could also explain the absence of contagion among staff inside ICUs.