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Journal of Medical Virology May 2024Understanding how the infectious disease burden was affected throughout the COVID-19 pandemic is pivotal to identifying potential hot spots and guiding future mitigation...
Understanding how the infectious disease burden was affected throughout the COVID-19 pandemic is pivotal to identifying potential hot spots and guiding future mitigation measures. Therefore, our study aimed to analyze the changes in the rate of new cases of Poland's most frequent infectious diseases during the entire COVID-19 pandemic and after the influx of war refugees from Ukraine. We performed a registry-based population-wide study in Poland to analyze the changes in the rate of 24 infectious disease cases from 2020 to 2023 and compared them to the prepandemic period (2016-2019). Data were collected from publicly archived datasets of the Epimeld database published by national epidemiological authority institutions. The rate of most of the studied diseases (66.6%) revealed significantly negative correlations with the rate of SARS-CoV-2 infections. For the majority of infectious diseases, it substantially decreased in 2020 (in case of 83%) and 2021 (63%), following which it mostly rebounded to the prepandemic levels and, in some cases, exceeded them in 2023 when the exceptionally high annual rates of new cases of scarlet fever, Streptococcus pneumoniae infections, HIV infections, syphilis, gonococcal infections, and tick-borne encephalitis were noted. The rate of Clostridioides difficile enterocolitis was two-fold higher than before the pandemic from 2021 onward. The rate of Legionnaires' disease in 2023 also exceeded the prepandemic threshold, although this was due to a local outbreak unrelated to lifted COVID-19 pandemic restrictions or migration of war refugees. The influx of war migrants from Ukraine could impact the epidemiology of sexually transmitted diseases. The present analysis indicates that continued efforts are needed to prevent COVID-19 from overwhelming healthcare systems again and decreasing the control over the burden of other infectious diseases. It also identifies the potential tipping points that require additional mitigation measures, which are also discussed in the paper, to avoid escalation in the future.
Topics: Humans; COVID-19; Ukraine; Poland; Refugees; Communicable Diseases; SARS-CoV-2; Female; Male; Pandemics; Adult; Registries; Cost of Illness; Armed Conflicts
PubMed: 38712743
DOI: 10.1002/jmv.29651 -
European Journal of Clinical... May 2024Although not fully investigated, studies show that Legionella pneumophila can develop antibiotic resistance. As there is limited data available for Portugal, we...
BACKGROUD
Although not fully investigated, studies show that Legionella pneumophila can develop antibiotic resistance. As there is limited data available for Portugal, we determined the antibiotic susceptibility profile of Portuguese L. pneumophila serogroup 1 (LpnSg1) isolates against antibiotics used in the clinical practice in Portugal.
METHODS
Minimum inhibitory concentrations (MICs) were determined for LpnSg1 clinical (n = 100) and related environmental (n = 7) isolates, collected between 2006-2022 in the context of the National Legionnaire´s Disease Surveillance Programme, against azithromycin, clarithromycin, erythromycin, levofloxacin, ciprofloxacin, moxifloxacin, rifampicin, doxycycline, tigecycline, and amoxicillin/clavulanic acid, using three different assays. Isolates were also PCR-screened for the presence of the lpeAB gene.
RESULTS
Twelve isolates had azithromycin MICs above the EUCAST tentative highest WT MIC, 9 of which were lpeAB negative; for erythromycin and clarithromycin, all isolates tested within the susceptible range. The number of isolates with MICs above the tentative highest WT MIC for the remaining antibiotics was: ciprofloxacin: 7; levofloxacin: 17; moxifloxacin: 8; rifampicin: 11; doxycycline: 82; tigecycline: 4. EUCAST breakpoints are not available for amoxicillin/clavulanic acid. We estimated the ECOFFs and one isolate had a MIC eightfold higher than the E-test ECOFF. Additionally, a clinical isolate generated three colonies growing on the E-test inhibition zone that resulted in MICs fourfold higher than for the parental isolate.
CONCLUSIONS
We report, for the first time, elevated MICs against first-line and other antibiotics (including azithromycin, fluoroquinolones and amoxicillin/clavulanic acid commonly used to treat pneumonia patients in Portugal) in Portuguese L. pneumophila strains. Results point towards decreased susceptibility in circulating strains, justifying further investigation.
PubMed: 38696083
DOI: 10.1007/s10096-024-04789-9 -
Microbiology Resource Announcements Jun 2024Legionnaires' disease is a severe form of pneumonia caused by spp. bacteria. According to the European Centre for Disease Prevention and Control, problems related to...
Legionnaires' disease is a severe form of pneumonia caused by spp. bacteria. According to the European Centre for Disease Prevention and Control, problems related to this pathogen showed a significant surge in recent years, making its monitoring critical.
PubMed: 38690889
DOI: 10.1128/mra.01154-23 -
MBio Jun 2024The causative agent of Legionnaires' disease, , is an environmental bacterium, that replicates in macrophages, parasitizes amoeba, and forms biofilms. employs the...
UNLABELLED
The causative agent of Legionnaires' disease, , is an environmental bacterium, that replicates in macrophages, parasitizes amoeba, and forms biofilms. employs the quorum sensing (Lqs) system and the transcription factor LvbR to control various bacterial traits, including virulence and biofilm architecture. LvbR negatively regulates the nitric oxide (NO) receptor Hnox1, linking quorum sensing to NO signaling. Here, we assessed the response of to NO and investigated bacterial receptors underlying this process. Chemical NO donors, such as dipropylenetriamine (DPTA) NONOate and sodium nitroprusside (SNP), delayed and reduced the expression of the promoters for flagellin (P) and the 6S small regulatory RNA (P). Marker-less mutant strains lacking individual (Hnox1, Hnox2, or NosP) or all three NO receptors (triple knockout, TKO) grew like the parental strain in media. However, in the TKO strain, the reduction of P expression by DPTA NONOate was less pronounced, suggesting that the NO receptors are implicated in NO signaling. In the Δ mutant, the promoter was upregulated, indicating that NosP negatively regulates LvbR. The single and triple NO receptor mutant strains were impaired for growth in phagocytes, and phenotypic heterogeneity of non-growing/growing bacteria in amoebae was regulated by the NO receptors. The single NO receptor and TKO mutant strains showed altered biofilm architecture and lack of response of biofilms to NO. In summary, we provide evidence that regulates virulence, intracellular phenotypic heterogeneity, and biofilm formation through NO and three functionally non-redundant NO receptors, Hnox1, Hnox2, and NosP.
IMPORTANCE
The highly reactive diatomic gas molecule nitric oxide (NO) is produced by eukaryotes and bacteria to promote short-range and transient signaling within and between neighboring cells. Despite its importance as an inter-kingdom and intra-bacterial signaling molecule, the bacterial response and the underlying components of the signaling pathways are poorly characterized. The environmental bacterium forms biofilms and replicates in protozoan and mammalian phagocytes. harbors three putative NO receptors, one of which crosstalks with the quorum sensing (Lqs)-LvbR network to regulate various bacterial traits, including virulence and biofilm architecture. In this study, we used pharmacological, genetic, and cell biological approaches to assess the response of to NO and to demonstrate that the putative NO receptors are implicated in NO detection, bacterial replication in phagocytes, intracellular phenotypic heterogeneity, and biofilm formation.
Topics: Biofilms; Legionella pneumophila; Nitric Oxide; Signal Transduction; Virulence; Gene Expression Regulation, Bacterial; Bacterial Proteins; Phenotype; Macrophages; Quorum Sensing
PubMed: 38682908
DOI: 10.1128/mbio.00710-24 -
Journal of Infection and Public Health Jun 2024Legionellers' desease accounts for 1-8 % of cases of severe community-acquired pneumonia (CAP). Legionella spp. Is the causative organism that can result in respiratory...
Legionellers' desease accounts for 1-8 % of cases of severe community-acquired pneumonia (CAP). Legionella spp. Is the causative organism that can result in respiratory failure, multi-organ dysfunction, sepsis, and death. Therefore, rapid diagnosis and efficient treatment are crucial. We report the clinical and microbiology study of a patient with community-acquired pneumonia caused by Legionella pneumophila, with fatal outcome. After death, the strain causing the infection was identified as Legionella pneumophila serogroup 1, Olda OLDA phenotype and sequence-type 1. This is the first reported case of septic shock and death associated with an isolate of these characteristics.
Topics: Humans; Community-Acquired Infections; Legionella pneumophila; Shock, Septic; Legionnaires' Disease; Fatal Outcome; Male; Aged; Serogroup; Middle Aged
PubMed: 38678725
DOI: 10.1016/j.jiph.2024.04.019 -
Emerging Infectious Diseases May 2024We investigated molecular evolution and spatiotemporal dynamics of atypical Legionella pneumophila serogroup 1 sequence type 1905 and determined its long-term...
We investigated molecular evolution and spatiotemporal dynamics of atypical Legionella pneumophila serogroup 1 sequence type 1905 and determined its long-term persistence and linkage to human disease in dispersed locations, far beyond the large 2014 outbreak epicenter in Portugal. Our finding highlights the need for public health interventions to prevent further disease spread.
Topics: Legionella pneumophila; Portugal; Humans; Legionnaires' Disease; Spatio-Temporal Analysis; Evolution, Molecular; Disease Outbreaks; History, 21st Century; Recurrence; Phylogeny; Serogroup
PubMed: 38666647
DOI: 10.3201/eid3005.231383 -
The Science of the Total Environment Jun 2024There is little evidence of the long-term consequences of maintaining sanitary hot water at high temperatures on the persistence of Legionella in the plumbing system....
There is little evidence of the long-term consequences of maintaining sanitary hot water at high temperatures on the persistence of Legionella in the plumbing system. The aims of this study were to describe the persistence and genotypic variability of L. pneumophila in a hospital building with two entirely independent hot water distribution systems, and to estimate the thermotolerance of the genotypic variants by studying the quantity of VBNC L. pneumophila. Eighty isolates from 55 water samples obtained between the years 2012-2017 were analyzed. All isolates correspond to L. pneumophila serogroup 6. The isolates were discriminated in four restriction patterns by pulsed-field gel electrophoresis. In one installation, pattern A + Aa predominated, accounting for 75.8 % of samples, while the other installation exhibited pattern B as the most frequent (81.8 % of samples; p < 0.001). The mean temperature of the isolates was: 52.6 °C (pattern A + Aa) and 55.0 °C (pattern B), being significantly different. Nine strains were selected as representative among patterns to study their thermotolerance by flow-cytometry after 24 h of thermic treatment. VBNC bacteria were detected in all samples. After thermic treatment at 50 °C, 52.0 % of bacteria had an intact membrane, and after 55 °C this percentage decreased to 23.1 %. Each pattern exhibited varying levels of thermotolerance. These findings indicate that the same hospital building can be colonized with different predominant types of Legionella if it has independent hot water installations. Maintaining a minimum temperature of 50 °C at distal points of the system would allow the survival of replicative L. pneumophila. However, the presence of Legionella in hospital water networks is underestimated if culture is considered as the standard method for Legionella detection, because VBNC do not grow on culture plates. This phenomenon can carry implications for the Legionella risk management plans in hospitals that adjust their control measures based on the microbiological surveillance of water.
Topics: Cross Infection; Hospitals; Hot Temperature; Legionella pneumophila; Microbial Viability; Thermotolerance; Time Factors; Water Supply; Legionnaires' Disease; Colony Count, Microbial; Humans
PubMed: 38608884
DOI: 10.1016/j.scitotenv.2024.172410 -
Case Reports in Pulmonology 2024Legionella bozemanii pneumonia is a rare form of Legionnaires' disease caused by the bacterium Legionella bozemanii. It is well known to cause pneumonia in...
Legionella bozemanii pneumonia is a rare form of Legionnaires' disease caused by the bacterium Legionella bozemanii. It is well known to cause pneumonia in immunocompromised patients and has rarely been reported in immunocompetent hosts. We describe a case of a 59-year-old immunocompetent female presented with pneumonia, acute respiratory failure, acute respiratory distress, and septic shock, who was treated with azithromycin, goal-directed resuscitation, and extracorporeal membrane oxygenation (ECMO) but did not survive. Clinicians should have high suspicion of rare legionella pathogens as causative agents for pneumonia.
PubMed: 38596699
DOI: 10.1155/2024/7571380 -
Cell Reports Apr 2024Small GTPases of the Ras subfamily are best known for their role as proto-oncoproteins, while their function during microbial infection has remained elusive. Here, we...
Small GTPases of the Ras subfamily are best known for their role as proto-oncoproteins, while their function during microbial infection has remained elusive. Here, we show that Legionella pneumophila hijacks the small GTPase NRas to the Legionella-containing vacuole (LCV) surface. A CRISPR interference screen identifies a single L. pneumophila effector, DenR (Lpg1909), required for this process. Recruitment is specific for NRas, while its homologs KRas and HRas are excluded from LCVs. The C-terminal hypervariable tail of NRas is sufficient for recruitment, and interference with either NRas farnesylation or S-acylation sites abrogates recruitment. Intriguingly, we detect markers of active NRas signaling on the LCV, suggesting it acts as a signaling platform. Subsequent phosphoproteomics analyses show that DenR rewires the host NRas signaling landscape, including dampening of the canonical mitogen-activated protein kinase pathway. These results provide evidence for L. pneumophila targeting NRas and suggest a link between NRas GTPase signaling and microbial infection.
Topics: Legionella pneumophila; Humans; Membrane Proteins; MAP Kinase Signaling System; GTP Phosphohydrolases; Bacterial Proteins; Down-Regulation; HEK293 Cells; Legionnaires' Disease; Vacuoles; Proto-Oncogene Proteins p21(ras)
PubMed: 38568811
DOI: 10.1016/j.celrep.2024.114033 -
Annals of Intensive Care Apr 2024Legionnaires' disease (LD) is a common but under-diagnosed cause of community-acquired pneumonia (CAP), although rapid detection of urine antigen testing (UAT) and... (Review)
Review
BACKGROUND
Legionnaires' disease (LD) is a common but under-diagnosed cause of community-acquired pneumonia (CAP), although rapid detection of urine antigen testing (UAT) and advances in molecular testing have improved the diagnosis. LD entails intensive care unit (ICU) admission in almost one-third of cases, and the mortality rate ranges from 4% to 40%. This review aims to discuss recent advances in the study of this condition and to provide an update on the diagnosis, pathogenesis and management of severe LD.
RESULTS
The overall incidence of LD has increased worldwide in recent years due to the higher number of patients with risk factors, especially immunosuppression, and to improvements in diagnostic methods. Although LD is responsible for only around 5% of all-cause CAP, it is one of the three most common causes of CAP requiring ICU admission. Mortality in ICU patients, immunocompromised patients or patients with a nosocomial source of LD can reach 40% despite appropriate antimicrobial therapy. Regarding pathogenesis, no Legionella-specific virulence factors have been associated with severity; however, recent reports have found high pulmonary Legionella DNA loads, and impairments in immune response and lung microbiome in the most severe cases. The clinical picture includes severe lung injury requiring respiratory and/or hemodynamic support, extrapulmonary symptoms and non-specific laboratory findings. LD diagnostic methods have improved due to the broad use of UAT and the development of molecular methods allowing the detection of all Lp serogroups. Therapy is currently based on macrolides, quinolones, or a combination of the two, with prolonged treatment in severe cases.
CONCLUSIONS
Numerous factors influence the mortality rate of LD, such as ICU admission, the underlying immune status, and the nosocomial source of the infection. The host immune response (hyperinflammation and/or immunoparalysis) may also be associated with increased severity. Given that the incidence of LD is rising, studies on specific biomarkers of severity may be of great interest. Further assessments comparing different regimens and/or evaluating host-directed therapies are nowadays needed.
PubMed: 38565811
DOI: 10.1186/s13613-024-01252-y