Interactions between Aeromonas caviae and Yersinia enterocolitica isolated from a case of diarrhea: evaluation of antimicrobial susceptibility and immune response of infected macrophages.

Aeromonas species cause a wide spectrum of human diseases, primarily gastroenteritis, septicemia, and wound infections. Several studies have shown that about 40% of these cases involve mixed or polymicrobial infections between Aeromonas spp. and bacteria from other genera. However, the immune response of macrophages in front of the bacteria present in the mixed infections, as well as their impact on antimicrobial therapy, have not been investigated. This study evaluated the cell damage and immune response of the mouse macrophage BALB/c cell line (J774A.1) after performing a single and a mixed infection with a strain of Aeromonas caviae and Yersinia enterocolitica, both recovered from the same fecal sample from a patient with diarrhea. Macrophage cell damage was measured by the release of lactate dehydrogenase (LDH) while the immune response was evaluated studying the expression by RT-qPCR of six relevant immune-related genes. Additionally, the antimicrobial susceptibility pattern of the single and mixed strains in front of seventeen antibiotics was evaluated to determine the potential impact on the infection treatment. Macrophages infected with the mixture of the two strains showed a higher cell damage in comparison with the single infections and the immune-related genes, i.e., cytokines and chemokines genes (TNF-α, CCL20), and apoptotic and pyroptotic genes (TP53 and IL-1ß) were overexpressed. After infection with the mixed cultures, an increase in the antimicrobial resistance was observed for ciprofloxacin, trimethoprim, chloramphenicol, gentamicin and ertapenem. This study increased the knowledge about the synergetic effect of the bacteria involved in mixed infection and on their potential impact on the treatment and evolution of the infection.

Prognostic implications of myocardial injury in patients with and without COVID-19 infection treated in a university hospital.

INTRODUCTION AND OBJECTIVES: Cardiac troponin, a marker of myocardial injury, is frequently observed in patients with COVID-19 infection. Our objective was to analyze myocardial injury and its prognostic implications in patients with and without COVID-19 infection treated in the same period of time. METHODS: The present study included patients treated in a university hospital with cardiac troponin I measurements and with suspected COVID-19 infection, confirmed or ruled out by polymerase chain reaction analysis. The impact was analyzed of cardiac troponin I positivity on 30-day mortality. RESULTS: In total, 433 patients were distributed among the following groups: confirmed COVID-19 (n=186), 22% with myocardial injury (n=41); and ruled out COVID-19 (n=247), 21.5% with myocardial injury (n=52). The confirmed and ruled out COVID-19 groups had a similar age, sex, and cardiovascular history. Mortality was significantly higher in the confirmed COVID-19 group than in the ruled out group (19.9% vs 5.3%, P <.001). In Cox multivariate regression analysis, cardiac troponin I was a predictor of mortality in both groups (confirmed COVID-19 group: HR, 3.54; 95%CI, 1.70-7.34; P=.001; ruled out COVID-19 group: HR, 5.57; 95%CI, 1.70-18.20; P=.004). The predictive model analyzed by ROC curves was similar in the 2 groups (P=.701), with AUCs of 0.808 in the confirmed COVID-19 group (0.750-0.865) and 0.812 in the ruled out COVID-19 group (0.760-0.864). CONCLUSIONS: Myocardial injury is detected in 1 in every 5 patients with confirmed or ruled out COVID-19 and predicts 30-day mortality to a similar extent in both circumstances.

[Prognostic implications of myocardial injury in patients with and without COVID-19 infection treated in a university hospital]. / Implicaciones pronósticas del daño miocárdico en pacientes con y sin diagnóstico confirmado de COVID-19 atendidos en un hospital universitario.

INTRODUCTION AND OBJECTIVES: Cardiac troponin, a marker of myocardial injury, is frequently observed in patients with COVID-19 infection. Our objective was to analyze myocardial injury and its prognostic implications in patients with and without COVID-19 infection treated in the same period of time. METHODS: The present study included patients treated in a university hospital with cardiac troponin I measurements and with suspected COVID-19 infection, confirmed or ruled out by polymerase chain reaction analysis. The impact was analyzed of cardiac troponin I positivity on 30-day mortality. RESULTS: In total, 433 patients were distributed among the following groups: confirmed COVID-19 (n = 186), 22% with myocardial injury (n = 41); and ruled out COVID-19 (n = 247), 21.5% with myocardial injury (n = 52). The confirmed and ruled out COVID-19 groups had a similar age, sex, and cardiovascular history. Mortality was significantly higher in the confirmed COVID-19 group than in the ruled out group (19.9% vs 5.3%, P < .001). In Cox multivariate regression analysis, cardiac troponin I was a predictor of mortality in both groups (confirmed COVID-19 group: HR, 3.54; 95%CI, 1.70-7.34; P = .001; ruled out COVID-19 group: HR, 5.57; 95%CI, 1.70-18.20; P = .004). The predictive model analyzed by ROC curves was similar in the 2 groups (P = .701), with AUCs of 0.808 in the confirmed COVID-19 group (0.750-0.865) and 0.812 in the ruled out COVID-19 group (0.760-0.864). CONCLUSIONS: Myocardial injury is detected in 1 in every 5 patients with confirmed or ruled out COVID-19 and predicts 30-day mortality to a similar extent in both circumstances.

Antimicrobial susceptibility, virulence potential and sequence types associated with Arcobacter strains recovered from human faeces.

PURPOSE: The genus Arcobacter includes bacteria that are considered emergent pathogens because they can produce infections in humans and animals. The most common symptoms are bloody and non-bloody persistent diarrhea but cases with abdominal cramps without diarrhea or asymptomatic cases have also been described as well as cases with bacteremia. The objective was to characterize Arcobacter clinical strains isolated from the faeces of patients from three Spanish hospitals. METHODOLOGY: We have characterized 28 clinical strains (27 of A. butzleri and one of A. cryaerophilus) isolated from faeces, analysing their epidemiological relationship using the multilocus sequence typing (MLST) approach and screening them for their antibiotic susceptibility and for the presence of virulence genes.Results/Key findings. Typing results showed that only one of the 28 identified sequence types (i.e. ST 2) was already present in the MLST database. The other 27 STs constituted new records because they included new alleles for five of the seven genes or new combinations of known alleles of the seven genes. All strains were positive for the ciaB virulence gene and sensitive to tetracycline. However, 7.4 % of the A. butzleri and A. cryaerophilus strains showed resistance to ciprofloxacin. CONCLUSION: The fact that epidemiological unrelated strains show the same ST indicates that other techniques with higher resolution should be developed to effectively recognize the infection source. Resistance to ciprofloxacin, one of the antibiotics recommended for the treatment of Arcobacter intestinal infections, demonstrated in 10.7 % of the strains, indicates the importance of selecting the most appropriate effective treatment.