C-terminal deletion of RelA protein is suggested as a possible cause of infective endocarditis recurrence with Enterococcus faecium.

Infective endocarditis (IE) caused by Enterococcus spp. represents the third most common cause of IE, with high rates of relapse compared with other bacteria. Interestingly, late relapses (>6 months) have only been described in Enterococcus faecalis, but here we describe the first reported IE relapse with Enterococcus faecium more than a year (17 months) after the initial endocarditis episode. Firstly, by multi locus sequence typing (MLST), we demonstrated that both isolates (EF646 and EF641) belong to the same sequence type (ST117). Considering that EF641 was able to overcome starvation and antibiotic treatment conditions surviving for a long period of time, we performed bioinformatic analysis in identifying potential genes involved in virulence and stringent response. Our results showed a 13-nucleotide duplication (positions 1638-1650) in the gene relA, resulting in a premature stop codon, with a loss of 167 amino acids from the C-terminal domains of the RelA enzyme. RelA mediates the stringent response in bacteria, modulating levels of the alarmone guanosine tetraphosphate (ppGpp). The relA mutant (EF641) was associated with lower growth capacity, the presence of small colony variants, and higher capacity to produce biofilms (compared with the strain EF646), but without differences in antimicrobial susceptibility patterns according to standard procedures during planktonic growth. Instead, EF641 demonstrated tolerance to high doses of teicoplanin when growing in a biofilm. We conclude that all these events would be closely related to the long-term survival of the E. faecium and the late relapse of the IE. These data represent the first clinical evidence of mutations in the stringent response (relA gene) related with E. faecium IE relapse.

Rapid Detection of Piperacillin-Tazobactam Resistance in Klebsiella pneumoniae and Escherichia coli.

Rapid determination of susceptibility to piperacillin-tazobactam (TZP) is very important since the development of antibiotic resistance and inadequate treatment could increase the risk of clinical failure in infected patients, especially if such resistance is unknown to the clinician. Therefore, based on color change from orange to yellow of phenol red due to glucose metabolism (bacterial growth) in the presence of an adequate concentration of TZP (10 mg/L piperacillin and 5 mg/L tazobactam), the RapidTZP test has been developed to detect TZP resistance in Escherichia coli and Klebsiella pneumoniae isolates in a maximum of 3 h. A total of 140 isolates, 43 of E. coli and 97 of K. pneumoniae, were used to evaluate the performance of the test, 60 being resistant to TZP. The sensitivity and specificity of the test were 98.24% and 100%, respectively. Additionally, the RapidTZP test was validated by a pellet obtained directly from blood culture bottles. A total of 37 positive blood cultures for E. coli and 43 for K. pneumoniae were used for validation, 8 of them resistant to TZP. The sensitivity and specificity shown in the evaluation were 100% for both parameters. This new test is easy, fast, and accurate, providing results in 3 h. IMPORTANCE TZP is an antibiotic widely used for the empirical treatment of severe infections such as bloodstream infections. However, resistance to TZP in K. pneumoniae and E. coli has been increasing in the last few years. Thus, rapid detection of TZP resistance is critical to optimize the empirical treatment of patients with severe infections. In this study, we developed and evaluated a rapid test (RapidTZP) for the detection of TZP resistance in K. pneumoniae and E. coli directly from positive hemocultures in just 3 h. This rapid test has been validated on 138 K. pneumoniae and E. coli clinical isolates directly from agar plates and 80 K. pneumoniae and E. coli isolates causing bloodstream infections. The results demonstrate that the RapidTZP test has great clinical potential to optimize the empirical treatment of patients with bloodstream infections.

[Sero-epidemiological study of SARS-CoV-2 infection among healthcare personnel in a healthcare department]. / Estudio de sero-epidemiología de la infección por SARS-CoV-2 en profesionales sanitarios de un departamento sanitario.

OBJECTIVE: Estimate IgG antibody prevalence against SARS-CoV-2 in healthcare personnel (HCP) of a healthcare department (HD). METHOD: Prevalence study. The presence of IgG antibodies against SARS-CoV-2 was determined in HCP of the HD. Enzyme linked immunosorbent assays (ELISA) tests were used. Field work took place from April 24, 2020 to May 8, 2020. The age, sex, occupation (physician, nurse, etc.) and the work area (Primary Care, Emergency Room, etc.) were gathered. The IgG antibody prevalence was then calculated with its 95% confidence interval (95% CI). To study the association between HCP characteristics and the presence IgG the Chi Square test was used, and to study the magnitude of association, the Odds Ratio (95% CI) was calculated. RESULTS: Of the 4813 HCP in the HD, 4179 (87,1%) participated. Of these, 73,3% (3065) were women and 26,7% (1114) men. The global prevalence of IgG antibodies against SARS-CoV-2 was 6,6% (95% CI: 5,8-7,3). There were statistically significant differences depending on the occupation, from 8,7% (95% CI: 6,9-10,6) on medics down to 3,2% (95% CI: 1,0-8,0) on personnel not associated with health care. The other characteristics did not associate significantly to antibody presence against SARS-CoV-2. CONCLUSION: The SARS-CoV-2 infection frequency in HCP is similar to the estimated in the general population for big cities in Spain. This highlights the effectiveness of the infection control and prevention programme in this healthcare department targeted at healthcare personnel.

Sero-epidemiological study of SARS-CoV-2 infection among healthcare personnel in a healthcare department.

OBJECTIVE: Estimate IgG antibody prevalence against SARS-CoV-2 in healthcare personnel (HCP) of a healthcare department (HD). METHOD: Prevalence study. The presence of IgG antibodies against SARS-CoV-2 was determined in HCP of the HD. Enzyme linked immunosorbent assays (ELISA) tests were used. Field work took place from April 24, 2020 to May 8, 2020. The age, sex, occupation (physician, nurse, etc.) and the work area (Primary Care, Emergency Room, etc.) were gathered. The IgG antibody prevalence was then calculated with its 95% confidence interval (95% CI). To study the association between HCP characteristics and the presence IgG the Chi Square test was used, and to study the magnitude of association, the Odds Ratio (95% CI) was calculated. RESULTS: Of the 4813 HCP in the HD, 4179 (87,1%) participated. Of these, 73,3% (3065) were women and 26,7% (1114) men. The global prevalence of IgG antibodies against SARS-CoV-2 was 6,6% (95% CI: 5,8-7,3). There were statistically significant differences depending on the occupation, from 8,7% (95% CI: 6,9-10,6) on medics down to 3,2% (95% CI: 1,0-8,0) on personnel not associated with health care. The other characteristics did not associate significantly to antibody presence against SARS-CoV-2. CONCLUSION: The SARS-CoV-2 infection frequency in HCP is similar to the estimated in the general population for big cities in Spain. This highlights the effectiveness of the infection control and prevention programme in this healthcare department targeted at healthcare personnel.

[Effectiveness of flu vaccine in the prevention of severe cases. Season 2018-2019]. / Efectividad de la vacuna de la gripe para prevenir casos graves. Temporada 2018/2019.

OBJECTIVE: To know the effectiveness of the 2018/2019 flu vaccine for the prevention of severe cases of flu in a tertiary hospital. METHOD: Case-control study. We included all patients hospitalized with influenza confirmed by laboratory during 2018/2019 season. Those who met the criteria of severe case of influenza (pneumonia, multiorgan failure, septic shock, ICU admission or death) were considered as cases. Non severe cases of influenza were included in the control group. We calculated the effectiveness of the raw and adjusted vaccine (to prevent severe cases of influenza) and its 95% confidence interval using formula VE=(1-odds ratio)×100. RESULTS: Effectiveness of flu vaccine adjusted by age group and comorbidities was 60.7% (20.5-80.5). In the analysis adjusted and restricted to each sex, age group and presence of comorbidities, the influenza vaccine had a positive effect in all groups and categories, with effectiveness in the age group 65 years or more being 55.0% (2.6-79.2). CONCLUSIONS: Flu vaccination reduced the severity of influenza in hospitalized patients. These findings should be taken into account to improve vaccination strategies and achieve better vaccination coverage in the high-risk population in order not only to decrease flu cases, but also their severity.