scholarly journals Prognostic factors of severe community-acquired staphylococcal pneumonia in France

2021 ◽  
pp. 2004445
Author(s):  
Yves Gillet ◽  
Anne Tristan ◽  
Jean-Philippe Rasigade ◽  
Mitra Saadatian-Elahi ◽  
Coralie Bouchiat ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Older Patients ◽  
Methicillin Resistance ◽  
Community Acquired Pneumonia ◽  
Genetic Lineage ◽  
Virulence Determinants ◽  
Multicentre Cohort Study ◽  
Staphylococcal Pneumonia ◽  
Specific Factors ◽  
Multicentre Cohort

PurposeStaphylococcus aureus causes severe forms of community-acquired pneumonia (CAP), namely staphylococcal pleuropneumonia in young children and staphylococcal necrotising pneumonia in older patients. Methicillin resistance, the Panton-Valentine leukocidin (PVL) toxin, as well as less specific factors have been associated with poor outcome in severe CAP, but their respective roles are unclear.MethodsA prospective multicentre cohort study of severe staphylococcal CAP was conducted in 77 paediatric and adult intensive care units in France between January 2011 and December 2016. After age-clustering, risk factors for mortality, including pre-existing conditions, clinical presentation, laboratory features, strain genetic lineage, PVL, other virulence factors, and methicillin resistance were assessed using univariate and multivariable Cox and LASSO regressions.ResultsOf 163 included patients, aged one month to 87 years, 85 (52.1%) had PVL-positive CAP; there were 20 (12.3%) patients aged <3 years (hereafter “toddlers”), among whom 19 (95%) had PVL-positive CAP. The features of PVL-positive CAP in toddlers matched with the historical description of staphylococcal pleuropneumonia, with a lower mortality (n=3/19, 15%) compared to PVL-positive CAP in older patients (n=31/66, 47%). Mortality in older patients was independently predicted by PVL-positivity (hazard ratio 1.81, 95% CI, 1.03 to 3.17) and methicillin resistance (2.37, 95% CI 1.29 to 4.34) independently from S. aureus lineages and the presence of other virulence determinants.ConclusionPVL was associated with staphylococcal pleuropneumonia in toddlers and was a risk factor for mortality in older patients with severe CAP, independently of methicillin resistance, S. aureus genetic background and other virulence factors.

scholarly journals Risk factors of severity in community-acquired staphylococcal pneumonia

2020 ◽  
Author(s):  
Yves Gillet ◽  
Anne Tristan ◽  
Jean-Philippe Rasigade ◽  
Mitra Saadatian-Elahi ◽  
Coralie Bouchiat ◽  
...  
Keyword(s):  
Risk Factors ◽  
Older Patients ◽  
Microbial Population ◽  
Cox Regression ◽  
Methicillin Resistance ◽  
Community Acquired Pneumonia ◽  
Multicenter Cohort Study ◽  
Multicenter Cohort ◽  
Staphylococcal Pneumonia ◽  
Panton Valentine Leukocidin

Background Staphylococcus aureus causes severe forms of community-acquired pneumonia (CAP), namely staphylococcal pleuropneumonia in young children and staphylococcal necrotizing pneumonia in older patients. Methicillin resistance and the Panton-Valentine leukocidin (PVL) toxin have both been associated with poor outcome in severe CAP, but their respective roles are unclear. Methods Prospective multicenter cohort study of severe staphylococcal CAP conducted in 77 pediatric and adult intensive care units in France between January 2011 and December 2016. Clinical features and outcomes were compared between toddlers (<3 years of age) and older patients with PVL-positive CAP; and between older patients with PVL-negative or PVL-positive CAP. Risk factors for mortality were identified using multivariate Cox regression. Results Of 163 included patients, aged one month to 87 years, 85 (52.1%) had PVL-positive CAP; there were 20 (12.3%) toddlers, among whom 19 (95%) had PVL-positive CAP. The features of PVL-positive CAP in toddlers matched with the historical description of staphylococcal pleuropneumonia, with a lower mortality (n = 3/19, 15%) compared to PVL-positive CAP in older patients (n=31/66, 47%). Mortality in older patients was independently predicted by PVL-positivity (hazard ratio 1.81, 95% CI, 1.03 to 3.17) and methicillin resistance (2.37, 95% CI 1.29 to 4.34). As genetic diversity was comparably high in PVL-positive and PVL-negative isolates, confounding by microbial population structure was unlikely. Conclusion PVL was associated with staphylococcal pleuropneumonia in toddlers and was a risk factor for mortality in older patients with severe CAP, independently of methicillin resistance. Funded by the French ministry of Health (PHRC 2010-A01132-37)

scholarly journals Revisiting the quorum-sensing hierarchy in Pseudomonas aeruginosa: the transcriptional regulator RhlR regulates LasR-specific factors

Microbiology ◽  
2009 ◽  
Vol 155 (3) ◽  
pp. 712-723 ◽  
Author(s):  
Valérie Dekimpe ◽  
Eric Déziel
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Transcriptional Regulator ◽  
Homoserine Lactone ◽  
The Other ◽  
Virulence Determinants ◽  
Late Stationary Phase ◽  
Regulatory Systems ◽  
Specific Factors

Pseudomonas aeruginosa uses the two major quorum-sensing (QS) regulatory systems las and rhl to modulate the expression of many of its virulence factors. The las system is considered to stand at the top of the QS hierarchy. However, some virulence factors such as pyocyanin have been reported to still be produced in lasR mutants under certain conditions. Interestingly, such mutants arise spontaneously under various conditions, including in the airways of cystic fibrosis patients. Using transcriptional lacZ reporters, LC/MS quantification and phenotypic assays, we have investigated the regulation of QS-controlled factors by the las system. Our results show that activity of the rhl system is only delayed in a lasR mutant, thus allowing the expression of multiple virulence determinants such as pyocyanin, rhamnolipids and C4-homoserine lactone (HSL) during the late stationary phase. Moreover, at this stage, RhlR is able to overcome the absence of the las system by activating specific LasR-controlled functions, including production of 3-oxo-C12-HSL and Pseudomonas quinolone signal (PQS). P. aeruginosa is thus able to circumvent the deficiency of one of its QS systems by allowing the other to take over. This work demonstrates that the QS hierarchy is more complex than the model simply presenting the las system above the rhl system.

scholarly journals Community-acquired pneumonia during the first post-pandemic influenza season: A prospective, multicentre cohort study

2013 ◽  
Vol 67 (3) ◽  
pp. 185-193 ◽  
Author(s):  
Diego Viasus ◽  
Carmen Marinescu ◽  
Aroa Villoslada ◽  
Elisa Cordero ◽  
Juan Gálvez-Acebal ◽  
...  
Keyword(s):  
Cohort Study ◽  
Pandemic Influenza ◽  
Influenza Season ◽  
Community Acquired Pneumonia ◽  
Multicentre Cohort Study ◽  
Multicentre Cohort

scholarly journals Age differences in clinical features and outcomes in patients with COVID-19, Jiangsu, China: a retrospective, multicentre cohort study

BMJ Open ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. e039887 ◽  
Author(s):  
Huanyuan Luo ◽  
Songqiao Liu ◽  
Yuancheng Wang ◽  
Penelope A Phillips-Howard ◽  
Shenghong Ju ◽  
...  
Keyword(s):  
Cohort Study ◽  
Intensive Care ◽  
Respiratory Failure ◽  
Hospital Stay ◽  
Older Patients ◽  
Adverse Outcomes ◽  
Trend Test ◽  
Chronic Obstructive ◽  
Multicentre Cohort Study ◽  
Multicentre Cohort

ObjectivesTo determine the age-specific clinical presentations and incidence of adverse outcomes among patients with COVID-19 in Jiangsu, China.Design and settingRetrospective, multicentre cohort study performed at 24 hospitals in Jiangsu, China.Participants625 patients with COVID-19 enrolled between 10 January and 15 March 2020.ResultsOf the 625 patients (median age, 46 years; 329 (52.6%) men), 37 (5.9%) were children (18 years or younger), 261 (41.8%) young adults (19–44 years), 248 (39.7%) middle-aged adults (45–64 years) and 79 (12.6%) elderly adults (65 years or older). The incidence of hypertension, coronary heart disease, chronic obstructive pulmonary disease and diabetes comorbidities increased with age (trend test, p<0.0001, p=0.0003, p<0.0001 and p<0.0001, respectively). Fever, cough and shortness of breath occurred more commonly among older patients, especially the elderly, compared with children (χ2 test, p=0.0008, 0.0146 and 0.0282, respectively). The quadrant score and pulmonary opacity score increased with age (trend test, both p<0.0001). Older patients had many significantly different laboratory parameters from younger patients. Elderly patients had the highest proportion of severe or critically-ill cases (33.0%, χ2 test p<0.0001), intensive care unit use (35.4%, χ2 test p<0.0001), respiratory failure (31.6%, χ2 test p<0.0001) and the longest hospital stay (median 21 days, Kruskal–Wallis test p<0.0001).ConclusionsElderly (≥65 years) patients with COVID-19 had the highest risk of severe or critical illness, intensive care use, respiratory failure and the longest hospital stay, which may be due partly to their having a higher incidence of comorbidities and poor immune responses to COVID-19.

Enterococcal Virulence Determinants In Urinary Tract Infection Patients

2012 ◽  
Vol 6 (1) ◽  
pp. 14-17
Author(s):  
Jabin Akhter ◽  
Shaheda Anwar ◽  
Sharmeen Ahmed
Keyword(s):  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Virulence Factors ◽  
Virulence Determinants ◽  
Microtitre Plate ◽  
Microbiological Method ◽  
Enterococcal Infection ◽  
Microtitre Plate Assay ◽  
Positive Frequency

Urinary tract infection caused by Enterococci has become frequent occurrences in health care settings. Currently they emerged with increasing resistance to multiple antibiotics.  Haemolysin, gelatinase and biofilm production are some markers that have been proposed as possible Enterococcal virulence factors. In view of the increasing importance of Enterococcal infection, the present study was designed to isolate and identify the Enterococci to the species level from urine of urinary tract infection patients and to investigate their possible virulence factors. Biofilm was detected on polystyrene microtitre plate to see the adherence of microorganism. Haemolysin production and gelatin hydrolysis detected by standard microbiological method. Fifty nine enterococcal isolates were speciated by conventional microbiological method and examined for their ability to form biofilm by microtitre plate assay. In this study, biofilm formations by Enterococci were found in 83.33% isolates from catheterized and 56.09% from non-catheterized patients. Aong them, E.faecalis & 50% E.faecium produced biofilm. About 43.63% E.faecalis & 10% E.faecium produced haemolysin and only one isolate were found to be gelatinase positive. Frequency of virulence factors (VFs) in combination was observed in this study. Two VFs (haemolysin and biofilm) were observed in 27.11% in combination and 3 VFs ( haemolysinm biofilm and gelatinase) were present in 1.69% isolates. These results suggest that although there may not be an absolute role for individual virulence determinants in infectivity, combinations of factors may play a role in allowing a biofilm infection to be more resistant to therapy.DOI: http://dx.doi.org/10.3329/bjmm.v6i1.19361 Bangladesh J Med Microbiol 2012; 06(01): 14-17

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