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PloS One 2024Pleural empyema is a serious complication of pneumonia in children. Negative bacterial cultures commonly impede optimal antibiotic therapy. To improve bacterial... (Observational Study)
Observational Study
Pleural empyema is a serious complication of pneumonia in children. Negative bacterial cultures commonly impede optimal antibiotic therapy. To improve bacterial identification, we developed a molecular assay and evaluated its performance compared with bacterial culture. Our multiplex-quantitative PCR to detect Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Haemophilus influenzae was assessed using bacterial genomic DNA and laboratory-prepared samples (n = 267). To evaluate clinical performance, we conducted the Molecular Assessment of Thoracic Empyema (MATE) observational study, enrolling children hospitalised with empyema. Pleural fluids were tested by bacterial culture and multiplex-qPCR, and performance determined using a study gold standard. We determined clinical sensitivity and time-to-organism-identification to assess the potential of the multiplex-qPCR to reduce the duration of empiric untargeted antibiotic therapy. Using spiked samples, the multiplex-qPCR demonstrated 213/215 (99.1%) sensitivity and 52/52 (100%) specificity for all organisms. During May 2019-March 2023, 100 children were enrolled in the MATE study; median age was 3.9 years (IQR 2-5.6). A bacterial pathogen was identified in 90/100 (90%) specimens by multiplex-qPCR, and 24/100 (24%) by bacterial culture (P <0.001). Multiplex-qPCR identified a bacterial cause in 68/76 (90%) culture-negative specimens. S. pneumoniae was the most common pathogen, identified in 67/100 (67%) specimens. We estimate our multiplex-qPCR would have reduced the duration of untargeted antibiotic therapy in 61% of cases by a median 20 days (IQR 17.5-23, range 1-55). Multiplex-qPCR significantly increased pathogen detection compared with culture and may allow for reducing the duration of untargeted antibiotic therapy.
Topics: Humans; Child, Preschool; Empyema, Pleural; Male; Female; Multiplex Polymerase Chain Reaction; Child; Haemophilus influenzae; Staphylococcus aureus; Streptococcus pneumoniae; Streptococcus pyogenes; Infant; Hospitalization; Anti-Bacterial Agents; Sensitivity and Specificity; DNA, Bacterial
PubMed: 38917227
DOI: 10.1371/journal.pone.0304861 -
Emerging Infectious Diseases Jul 2024Pasteurella bettyae is a gram-negative bacillus sporadically involved in human infections; its main reservoirs are cats and dogs. A recent publication suggests the...
Pasteurella bettyae is a gram-negative bacillus sporadically involved in human infections; its main reservoirs are cats and dogs. A recent publication suggests the possibility of sexual transmission leading to genital infections in men who have sex with men. We report 9 cases in France of genital infection among this population.
Topics: Humans; Male; France; Adult; Homosexuality, Male; Pasteurella Infections; Pasteurella; Middle Aged; Young Adult
PubMed: 38916800
DOI: 10.3201/eid3007.240352 -
Emayella augustorita, New Member of Pasteurellaceae, Isolated from Blood Cultures of Septic Patient.Emerging Infectious Diseases Jun 2024We report discovery of a new bacterial genus and species of the family Pasteurellaceae by using phylogenetic and metabolic analysis. The bacterium, Emayella augustorita,...
We report discovery of a new bacterial genus and species of the family Pasteurellaceae by using phylogenetic and metabolic analysis. The bacterium, Emayella augustorita, was isolated from blood cultures of a patient in France diagnosed with an adenocarcinoma of the intestines and who was treated with a biliary prosthesis placement.
PubMed: 38907366
DOI: 10.3201/eid3008.231651 -
Current Microbiology Jun 2024Mannheimia haemolytica is recognized as principal pathogen associated with pneumonic pasteurellosis leading to huge economic losses to small ruminant farmers. Even...
Mannheimia haemolytica is recognized as principal pathogen associated with pneumonic pasteurellosis leading to huge economic losses to small ruminant farmers. Even though the disease causes huge economic losses, epidemiology of M. haemolytica is less studied, hindering the formulation of effective control strategies. Current study aimed to highlight molecular characterisation of M. haemolytica strains isolated from ovine pneumonic infection. M. haemolytica 27 isolates with two reference strains were characterised using capsular and virulence gene typing, multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) methods. M. haemolytica serotype A2 recognized as predominant serotype (74%) followed by A6 (11%) and A1 (5%) serotypes. Virulence gene profiling by PCRs showed dominance of all five virulent genes [such as adh and gcp (100% each)] followed by gs60 (88.8%), lktC (85.2%), tbpB (51.9%) and least nmaA gene (14.8%). MLST profiling delineated M. haemolytic isolates into 11 sequence types (STs) with most prevalent being ST37 (27.9%) and ST16 (23%) and nine new STs (ST37, 38, 39, 40, 41, 42, 47, 48, and 49). These new STs did not belong to any of the three clonal complexes (CC4, CC8 and CC28). ST16 was exclusively noted in A1 and A6 serotypes. Amongst 25 isolates, 22 pulsotypes (GD 0.88) recorded indicated variability of the M. haemolytica isolates in PFGE analysis. In conclusion, the study suggested dominance of M. haemolytica serotype A2 harbouring different virulent genes, diverse STs and pulsotypes responsible for pneumonic pasteurellosis frequently encountered in sheep.
Topics: Animals; Mannheimia haemolytica; Sheep; Sheep Diseases; India; Multilocus Sequence Typing; Pasteurellosis, Pneumonic; Serogroup; Electrophoresis, Gel, Pulsed-Field; Virulence Factors; Virulence; Phylogeny
PubMed: 38862704
DOI: 10.1007/s00284-024-03740-7 -
Aging Jun 2024Acute pancreatitis (AP) is a prevalent acute abdominal condition, and AP induced colonic barrier dysfunction is commonly observed. Total flavonoids of (TFC) have...
BACKGROUND
Acute pancreatitis (AP) is a prevalent acute abdominal condition, and AP induced colonic barrier dysfunction is commonly observed. Total flavonoids of (TFC) have exhibited noteworthy anti-inflammatory and anti-apoptotic properties.
METHODS
We established AP models, both in animals and cell cultures, employing Cerulein. 16S rRNA gene sequencing was performed to investigate the gut microorganisms changes.
RESULTS
, TFC demonstrated a remarkable capacity to ameliorate AP, as indicated by the inhibition of serum amylase, myeloperoxidase (MPO) levels, and the reduction in pancreatic tissue water content. Furthermore, TFC effectively curtailed the heightened inflammatory response. The dysfunction of colonic barrier induced by AP was suppressed by TFC. At the level, TFC treatment resulted in attenuation of increased cell apoptosis, and regulation of apoptosis related proteins expression in AR42J cells. The increase of , , , and by AP, and decrease of of , , by AP were both reversed by TFC treatment.
CONCLUSIONS
TFC can effectively suppress AP progression and AP induced colonic barrier dysfunction by mitigating elevated serum amylase, MPO levels, water content in pancreatic tissue, as well as curtailing inflammation, apoptosis. The findings presented herein shed light on the potential mechanisms by which TFC inhibit the development of AP progression and AP induced colonic barrier dysfunction.
Topics: Animals; Gastrointestinal Microbiome; Chrysanthemum; Pancreatitis; Flavonoids; Male; Rats; Colon; Apoptosis; Disease Models, Animal; Cell Line; Intestinal Mucosa
PubMed: 38862253
DOI: 10.18632/aging.205924 -
Archives of Microbiology Jun 2024A decreased chloramphenicol susceptibility in Haemophilus influenzae is commonly caused by the activity of chloramphenicol acetyltransferases (CATs). However, the...
A decreased chloramphenicol susceptibility in Haemophilus influenzae is commonly caused by the activity of chloramphenicol acetyltransferases (CATs). However, the involvement of membrane proteins in chloramphenicol susceptibility in H. influenzae remains unclear. In this study, chloramphenicol susceptibility testing, whole-genome sequencing, and analyses of membrane-related genes were performed in 51 H. influenzae isolates. Functional complementation assays and structure-based protein analyses were conducted to assess the effect of proteins with sequence substitutions on the minimum inhibitory concentration (MIC) of chloramphenicol in CAT-negative H. influenzae isolates. Six isolates were resistant to chloramphenicol and positive for type A-2 CATs. Of these isolates, A3256 had a similar level of CAT activity but a higher chloramphenicol MIC relative to the other resistant isolates; it also had 163 specific variations in 58 membrane genes. Regarding the CAT-negative isolates, logistic regression and receiver operator characteristic curve analyses revealed that 48T > G (Asn16Lys), 85 C > T (Leu29Phe), and 88 C > A (Leu30Ile) in HI_0898 (emrA), and 86T > G (Phe29Cys) and 141T > A (Ser47Arg) in HI_1177 (artM) were associated with enhanced chloramphenicol susceptibility, whereas 997G > A (Val333Ile) in HI_1612 (hmrM) was associated with reduced chloramphenicol susceptibility. Furthermore, the chloramphenicol MIC was lower in the CAT-negative isolates with EmrA-Leu29Phe/Leu30Ile or ArtM-Ser47Arg substitution and higher in those with HmrM-Val333Ile substitution, relative to their counterparts. The Val333Ile substitution was associated with enhanced HmrM protein stability and flexibility and increased chloramphenicol MICs in CAT-negative H. influenzae isolates. In conclusion, the substitution in H. influenzae multidrug efflux pump HmrM associated with reduced chloramphenicol susceptibility was characterised.
Topics: Chloramphenicol; Microbial Sensitivity Tests; Haemophilus influenzae; Anti-Bacterial Agents; Amino Acid Substitution; Bacterial Proteins; Chloramphenicol O-Acetyltransferase; Drug Resistance, Multiple, Bacterial; Membrane Transport Proteins; Chloramphenicol Resistance; Humans; Haemophilus Infections; Whole Genome Sequencing
PubMed: 38860999
DOI: 10.1007/s00203-024-04025-0 -
Frontiers in Immunology 2024is a bacterial pathogen that causes a variety of infections across diverse animal species, with one of the most devastating associated diseases being hemorrhagic...
BACKGROUND
is a bacterial pathogen that causes a variety of infections across diverse animal species, with one of the most devastating associated diseases being hemorrhagic septicemia. Outbreaks of hemorrhagic septicemia in cattle and buffaloes are marked by rapid progression and high mortality. These infections have particularly harmful socio-economic impacts on small holder farmers in Africa and Asia who are heavily reliant on a small number of animals kept as a means of subsistence for milk and draft power purposes. A novel vaccine target, PmSLP-3, has been identified on the surface of hemorrhagic septicemia-associated strains of and was previously shown to elicit robust protection in cattle against lethal challenge with a serogroup B strain.
METHODS
Here, we further investigate the protective efficacy of this surface lipoprotein, including evaluating the immunogenicity and protection upon formulation with a variety of adjuvants in both mice and cattle.
RESULTS
PmSLP-3 formulated with Montanide ISA 61 elicited the highest level of serum and mucosal IgG, elicited long-lasting serum antibodies, and was fully protective against serogroup B challenge. Studies were then performed to identify the minimum number of doses required and the needed protein quantity to maintain protection. Duration studies were performed in cattle, demonstrating sustained serum IgG titres for 3 years after two doses of vaccine and full protection against lethal serogroup B challenge at 7 months after a single vaccine dose. Finally, a serogroup E challenge study was performed, demonstrating that PmSLP-3 vaccine can provide protection against challenge by the two serogroups responsible for hemorrhagic septicemia.
CONCLUSION
Together, these data indicate that PmSLP-3 formulated with Montanide ISA 61 is an immunogenic and protective vaccine against hemorrhagic septicemia-causing strains in cattle.
Topics: Animals; Cattle; Pasteurella multocida; Hemorrhagic Septicemia; Bacterial Vaccines; Cattle Diseases; Mice; Antibodies, Bacterial; Female; Serogroup; Pasteurella Infections; Adjuvants, Immunologic; Immunoglobulin G; Mice, Inbred BALB C; Vaccination
PubMed: 38835751
DOI: 10.3389/fimmu.2024.1392681 -
BMC Veterinary Research Jun 2024Actinobacillus pleuropneumoniae is a serious pathogen in pigs. The abundant application of antibiotics has resulted in the gradual emergence of drugresistant bacteria,...
BACKGROUND
Actinobacillus pleuropneumoniae is a serious pathogen in pigs. The abundant application of antibiotics has resulted in the gradual emergence of drugresistant bacteria, which has seriously affected treatment of disease. To aid measures to prevent the emergence and spread of drug-resistant bacteria, herein, the kill rate and mutant selection window (MSW) of danofloxacin (DAN) against A. pleuropneumoniae were evaluated.
METHODS
For the kill rate study, the minimum inhibitory concentration (MIC) was tested using the micro dilution broth method and time-killing curves of DAN against A. pleuropneumoniae grown in tryptic soy broth (TSB) at a series drug concentrations (from 0 to 64 MIC) were constructed. The relationships between the kill rate and drug concentrations were analyzed using a Sigmoid E model during different time periods. For the MSW study, the MIC (the lowest concentration that inhibited the growth of the bacteria by ≥ 99%) and mutant prevention concentration (MPC) of DAN against A. pleuropneumoniae were measured using the agar plate method. Then, a peristaltic pump infection model was established to simulate the dynamic changes of DAN concentrations in pig lungs. The changes in number and sensitivity of A. pleuropneumoniae were measured. The relationships between pharmacokinetic/pharmacodynamic parameters and the antibacterial effect were analyzed using the Sigmoid E model.
RESULTS
In kill rate study, the MIC of DAN against A. pleuropneumoniae was 0.016 µg/mL. According to the kill rate, DAN exhibited concentration-dependent antibacterial activity against A. pleuropneumoniae. A bactericidal effect was observed when the DAN concentration reached 4-8 MIC. The kill rate increased constantly with the increase in DAN concentration, with a maximum value of 3.23 Log colony forming units (CFU)/mL/h during the 0-1 h period. When the drug concentration was in the middle part of the MSW, drugresistant bacteria might be induced. Therefore, the dosage should be avoided to produce a mean value of AUC/MIC (between 31.29 and 62.59 h. The values of AUC/MIC to achieve bacteriostatic, bactericidal, and eradication effects were 9.46, 25.14, and > 62.59 h, respectively.
CONCLUSION
These kill rate and MSW results will provide valuable guidance for the use of DAN to treat A. pleuropneumoniae infections.
Topics: Actinobacillus pleuropneumoniae; Microbial Sensitivity Tests; Anti-Bacterial Agents; Fluoroquinolones; Animals; Actinobacillus Infections; Swine; Drug Resistance, Bacterial; Swine Diseases; Mutation
PubMed: 38831324
DOI: 10.1186/s12917-024-04016-9 -
Scientific Reports Jun 2024The COVID-19 pandemic has altered the infection landscape for many pathogens. This retrospective study aimed to compare Haemophilus influenzae (H. influenzae) infections...
The COVID-19 pandemic has altered the infection landscape for many pathogens. This retrospective study aimed to compare Haemophilus influenzae (H. influenzae) infections in pediatric CAP patients hospitalized before (2018-2019) and during (2020-2022) the COVID-19 pandemic. We analyzed the clinical epidemiology and antimicrobial resistance (AMR) patterns of H. influenzae from a tertiary hospital in southwest China. A total of 986 pediatric CAP patients with H. influenzae-associated infections were included. Compared to 2018, the positivity rate increased in 2019 but dropped significantly in 2020. Although it rose in the following 2 years, the rate in 2022 remained significantly lower than in 2019. Patients' age during the pandemic was significantly higher than in 2018 and 2019, while gender composition remained similar across both periods. Notably, there were significant changes in co-infections with several respiratory pathogens during the pandemic. Resistance rates of H. influenzae isolates to antibiotics varied, with the highest resistance observed for ampicillin (85.9%) and the lowest for cefotaxime (0.0%). Resistance profiles to various antibiotics underwent dramatic changes during the COVID-19 pandemic. Resistance to amoxicillin-clavulanate, cefaclor, cefuroxime, trimethoprim-sulfamethoxazole, and the proportion of multi-drug resistant (MDR) isolates significantly decreased. Additionally, MDR isolates, alongside isolates resistant to specific drugs, were notably prevalent in ampicillin-resistant and β-lactamase-positive isolates. The number of pediatric CAP patients, H. influenzae infections, and isolates resistant to certain antibiotics exhibited seasonal patterns, peaking in the winter of 2018 and 2019. During the COVID-19 pandemic, sharp decreases were observed in February 2020, and there was no resurgence in December 2022. These findings indicate that the COVID-19 pandemic has significantly altered the infection spectrum of H. influenzae in pediatric CAP patients, as evidenced by shifts in positivity rate, demographic characteristics, respiratory co-infections, AMR patterns, and seasonal trends.
Topics: Humans; COVID-19; Male; Female; Haemophilus influenzae; Child; Child, Preschool; Haemophilus Infections; Retrospective Studies; Community-Acquired Infections; Infant; China; Anti-Bacterial Agents; Hospitalization; Adolescent; Pandemics; Coinfection; SARS-CoV-2; Drug Resistance, Bacterial
PubMed: 38830922
DOI: 10.1038/s41598-024-62728-2 -
The Canadian Veterinary Journal = La... Jun 2024
Topics: Animals; Swine Diseases; Swine; Quebec; Streptococcus suis; Serogroup; Streptococcal Infections; Actinobacillus pleuropneumoniae; Actinobacillus Infections
PubMed: 38827588
DOI: No ID Found