BACKGROUND: Data from surveillance on antibiotic resistance have shown an increasing prevalence of non-enzymatic resistance (β-lactamase-negative ampicillin-resistant) to β-lactam antibiotics among H. influenzae strains in the Czech Republic. Aminopenicillins are recommended agents for non-invasive Haemophilus influenzae infections. The phenomenon of non-enzymatic resistance to β-lactams is complicated by the fact that the phenotypic detection of PBP3 with specific amino acid substitutions (rPBP3) is challenging, since rPBP3 isolates have repeatedly been demonstrated to be split by the epidemiological cut-off values (ECOFF) for aminopenicillins defined by EUCAST. OBJECTIVES: We sought to determine whether the penicillin disc has sufficient detection ability to predict the non-enzymatic mechanism; whether other antibiotics can be used for detection; and what is the agreement between the broth microdilution and disc diffusion methods. METHODS: We undertook susceptibility testing of selected antibiotics according to EUCAST of 153 rPBP3 strains, and sequencing of the ftsI gene to determination amino acid substitutions. RESULTS: For a selected set of rPBP strains: (i) the detection capability for penicillin, ampicillin, cefuroxime and amoxicillin/clavulanate was found to be 91.5%, 94.4%, 89.5% and 70.6%, respectively; (ii) the categorical agreement between the disc diffusion method and the MIC for ampicillin and cefuroxime was 71.1% and 83.8%, respectively. CONCLUSIONS: We observed better recognition of rPBP3 strains by the ampicillin disc than by the penicillin disc. There is frequently a discrepancy in the interpretation of susceptibility results between the methods used.
- MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Bacterial Proteins * genetics MeSH
- beta-Lactam Resistance * MeSH
- beta-Lactams * pharmacology MeSH
- Phenotype MeSH
- Haemophilus influenzae * drug effects genetics isolation & purification enzymology MeSH
- Haemophilus Infections microbiology MeSH
- Humans MeSH
- Microbial Sensitivity Tests methods MeSH
- Penicillin-Binding Proteins * genetics MeSH
- Sequence Analysis, DNA MeSH
- Amino Acid Substitution * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
The ApxIVA protein belongs to a distinct class of a "clip and link" activity of Repeat-in-ToXin (RTX) exoproteins. Along with the three other pore-forming RTX toxins (ApxI, ApxII and ApxIII), ApxIVA serves as a major virulence factor of Actinobacillus pleuropneumoniae, the causative agent of porcine pneumonia. The gene encoding ApxIVA is located on a bicistronic operon downstream of the orf1 gene and is expressed exclusively under in vivo conditions. Both ApxIVA and ORF1 are essential for full virulence of A. pleuropneumoniae, but the molecular mechanisms by which they contribute to the pathogenicity are not yet understood. Here, we provide a comprehensive structural and functional analysis of ApxIVA and ORF1 proteins. Our findings reveal that the N-terminal segment of ApxIVA shares structural similarity with colicin M (ColM)-like bacteriocins and exhibits an antimicrobial activity. The ORF1 protein resembles the colicin M immunity protein (Cmi) and, like Cmi, is exported to the periplasm through its N-terminal signal peptide. Additionally, ORF1 can protect bacterial cells from the antimicrobial activity of ApxIVA, suggesting that ORF1 and ApxIVA function as an antibacterial toxin-immunity pair. Moreover, we demonstrate that fetal bovine serum could elicit ApxIVA and ORF1 production under in vitro conditions. These findings highlight the coordinated action of various RTX determinants, where the fine-tuned spatiotemporal production of ApxIVA may enhance the fitness of A. pleuropneumoniae, facilitating its invasion to a resident microbial community on the surface of airway mucosa.
- MeSH
- Actinobacillus pleuropneumoniae * genetics immunology MeSH
- Anti-Bacterial Agents pharmacology MeSH
- Bacterial Proteins * genetics metabolism immunology MeSH
- Bacterial Toxins genetics metabolism immunology MeSH
- Virulence Factors genetics MeSH
- Actinobacillus Infections microbiology veterinary MeSH
- Colicins genetics metabolism MeSH
- Operon * MeSH
- Swine MeSH
- Gene Expression Regulation, Bacterial MeSH
- Virulence MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
Předkládané sdělení popisuje případ systémové infekce vyvolané Pasteurella multocida. Infekce byla prokázána u 79letého muže, který byl do nemocničního zařízení dovezen po pádu z gauče. Onemocnění se projevilo rozvojem febrilního stavu, zimnicí, bolestmi kloubů a pádem. Laboratorně byla zjištěna elevace CRP, mírné zvýšení dusíkatých metabolitů, v krevním obraze hraniční leukocytóza, trombocytopenie. Agens bylo prokázáno v hemokultuře a v kultivačním vyšetření ve stěru z rány. Pacient byl léčen v úvodu cefalosporinem III. generace (cefotaxime), doléčován Xorimaxem. Článek je doplněn informacemi o etiologickém agens, jeho historii a přehledem literatury dokumentovaných komplikovaných případů pasteurelózy.
POZOR! při kopírování abstrakt kontrolovat slova na konci řádků originálu!!!
- MeSH
- Third Generation Cephalosporins pharmacology therapeutic use MeSH
- Bites and Stings microbiology MeSH
- Humans MeSH
- Pasteurella multocida pathogenicity MeSH
- Dogs * injuries MeSH
- Aged MeSH
- Sepsis * etiology microbiology MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Dogs * injuries MeSH
- Aged MeSH
- Publication type
- Case Reports MeSH
x
x
- MeSH
- Haemophilus influenzae * pathogenicity MeSH
- Haemophilus Infections * epidemiology mortality prevention & control MeSH
- Haemophilus Vaccines MeSH
- Disease Notification standards MeSH
- Humans MeSH
- Population Surveillance MeSH
- Check Tag
- Humans MeSH
- Publication type
- Chart MeSH
- Tables MeSH
- Geographicals
- Czech Republic MeSH
Secretory (S) IgA antibodies against severe acute respiratory syndrome (SARS)-CoV-2 are induced in saliva and upper respiratory tract (URT) secretions by natural infection and may be critical in determining the outcome of initial infection. Secretory IgA1 (SIgA1) is the predominant isotype of antibodies in these secretions. Neutralization of SARS-CoV-2 is most effectively accomplished by polymeric antibodies such as SIgA. We hypothesize that cleavage of SIgA1 antibodies against SARS-CoV-2 by unique bacterial IgA1 proteases to univalent Fabα antibody fragments with diminished virus neutralizing activity would facilitate the descent of the virus into the lungs to cause serious disease and also enhance its airborne transmission to others. Recent studies of the nasopharyngeal microbiota of patients with SARS-CoV-2 infection have revealed significant increases in the proportions of IgA1 protease-producing bacteria in comparison with healthy subjects. Similar considerations might apply also to other respiratory viral infections including influenza, possibly explaining the original attribution of influenza to Haemophilus influenzae, which produces IgA1 protease.
- MeSH
- Bacteria enzymology MeSH
- COVID-19 * transmission immunology virology microbiology MeSH
- Haemophilus influenzae enzymology immunology MeSH
- Immunoglobulin A, Secretory * metabolism MeSH
- Immunoglobulin A immunology MeSH
- Humans MeSH
- Nasopharynx microbiology virology MeSH
- Antibodies, Neutralizing immunology MeSH
- Antibodies, Viral immunology MeSH
- SARS-CoV-2 * immunology MeSH
- Serine Endopeptidases metabolism immunology MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Haemophilus ducreyi (HD) is an important cause of cutaneous ulcers in several endemic regions, including the Western Pacific Region, especially among children. An HD sequence typing on swab samples taken from 1,081 ulcers in the Namatanai district of Papua New Guinea, during the pilot study for treatment of yaws, has been performed using the Grant typing system. Of the 363 samples that tested positive for the 16S rDNA of HD, the dsrA sequences of 270 samples were determined. Altogether they revealed 8 HD strain types circulating in Namatanai, including seven strain types of Class I (I.3, I.4, I.5, I.9, I.10, I.11, I.12) and one strain of Class II (II.3); four Class I types (I.9, I.10, I.11, I.12) were novel. The southern region of Namatanai (Matalai Rural) was identified as the region with the lowest genotype diversity and with most infections caused by HD Class II. The middle and northern subdistricts were affected mainly by HD Class I. Analysis of patient characteristics revealed that Class II HD infections were more often represented by longer-lasting ulcers than Class I HD infections. An increase in the prevalence of the I.10 strain was found after azithromycin administration compared to the untreated population at baseline likely reflecting higher infectivity of HD Class I, and more specifically strain type I.10.
- MeSH
- Anti-Bacterial Agents * therapeutic use pharmacology MeSH
- Azithromycin * therapeutic use MeSH
- Child MeSH
- DNA, Bacterial genetics MeSH
- Adult MeSH
- Yaws microbiology epidemiology drug therapy MeSH
- Phylogeny MeSH
- Genotype * MeSH
- Haemophilus ducreyi * genetics isolation & purification drug effects MeSH
- Middle Aged MeSH
- Humans MeSH
- Chancroid * microbiology epidemiology drug therapy MeSH
- Adolescent MeSH
- Young Adult MeSH
- Pilot Projects MeSH
- Child, Preschool MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Sequence Analysis, DNA MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Male MeSH
- Child, Preschool MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Papua New Guinea MeSH
BACKGROUND: Aminopenicillins are recommended agents for non-invasive Haemophilus influenzae infections. One of the mechanisms of resistance to β-lactams is the alteration of the transpeptidase region of penicillin binding protein 3 (PBP3) which is caused by mutations in the ftsI gene. It was shown that exposure to beta-lactams has a stimulating effect on increase of prevalence of H. influenzae strains with the non-enzymatic mechanism of resistance. OBJECTIVES: The aim of our study was to compare the mutational potential of ampicillin and cefuroxime in H. influenzae strains, determination of minimum inhibitory concentration and the evolution of mutations over time, focusing on amino acid substitutions in PBP3. METHODS: 30 days of serial passaging of strains in liquid broth containing increasing concentrations of ampicillin or cefuroxime was followed by whole-genome sequencing. RESULTS: On average, cefuroxime increased the minimum inhibitory concentration more than ampicillin. The minimum inhibitory concentration was increased by a maximum of 32 fold. Substitutions in the PBP3 started to appear after 15 days of passaging. In PBP3, cefuroxime caused different substitutions than ampicillin. CONCLUSIONS: Our experiment observed differences in mutation selection by ampicillin and cefuroxime. Selection pressure of antibiotics in vitro generated substitutions that do not occur in clinical strains in the Czech Republic.
- MeSH
- Ampicillin * pharmacology MeSH
- Anti-Bacterial Agents * pharmacology MeSH
- Bacterial Proteins genetics metabolism MeSH
- Cefuroxime * pharmacology MeSH
- Haemophilus influenzae * genetics drug effects MeSH
- Haemophilus Infections microbiology MeSH
- Humans MeSH
- Microbial Sensitivity Tests * MeSH
- Evolution, Molecular MeSH
- Mutation * MeSH
- Penicillin-Binding Proteins * genetics metabolism MeSH
- Whole Genome Sequencing MeSH
- Selection, Genetic MeSH
- Serial Passage MeSH
- Amino Acid Substitution * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- MeSH
- Aggregatibacter actinomycetemcomitans pathogenicity MeSH
- Anti-Infective Agents therapeutic use MeSH
- Biofilms MeSH
- Child MeSH
- Adult MeSH
- Dental Implantation MeSH
- Humans MeSH
- Adolescent MeSH
- Papillon-Lefevre Disease * complications therapy MeSH
- Periodontitis complications therapy MeSH
- Subgingival Curettage MeSH
- Dental Implants MeSH
- Tooth, Deciduous pathology MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Humans MeSH
- Adolescent MeSH
- Male MeSH
- Female MeSH
- Publication type
- Case Reports MeSH
Akutní zánět středouší (otitis media acuta, OMA) patří stále k nejobvyklejším onemocněním u dětí. Článek se zaměřuje na jednotlivé bakteriální původce OMA u dětí, jejich charakteristiku, změny v čase, stav rezistence a doporučené postupy léčby OMA na základě aktuálních dat.
Acute otitis media (AOM) is still one of the most common diseases in children. The article focuses on the individual bacterial agents of AOM in children, their characteristics, changes over time, the state of resistance and recommended management for the treatment of AOM based on current data.
- MeSH
- Anti-Bacterial Agents pharmacology classification therapeutic use MeSH
- Child MeSH
- Haemophilus influenzae pathogenicity drug effects MeSH
- Humans MeSH
- Moraxella catarrhalis pathogenicity drug effects MeSH
- Otitis Media * etiology drug therapy microbiology MeSH
- Penicillin V pharmacology therapeutic use MeSH
- Penicillins pharmacology therapeutic use MeSH
- Practice Guidelines as Topic MeSH
- Streptococcus pneumoniae pathogenicity drug effects MeSH
- Streptococcus pyogenes pathogenicity drug effects MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Publication type
- Review MeSH
BACKGROUND: The Invasive Respiratory Infection Surveillance (IRIS) Consortium was established to assess the impact of the COVID-19 pandemic on invasive diseases caused by Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, and Streptococcus agalactiae. We aimed to analyse the incidence and distribution of these diseases during the first 2 years of the COVID-19 pandemic compared to the 2 years preceding the pandemic. METHODS: For this prospective analysis, laboratories in 30 countries and territories representing five continents submitted surveillance data from Jan 1, 2018, to Jan 2, 2022, to private projects within databases in PubMLST. The impact of COVID-19 containment measures on the overall number of cases was analysed, and changes in disease distributions by patient age and serotype or group were examined. Interrupted time-series analyses were done to quantify the impact of pandemic response measures and their relaxation on disease rates, and autoregressive integrated moving average models were used to estimate effect sizes and forecast counterfactual trends by hemisphere. FINDINGS: Overall, 116 841 cases were analysed: 76 481 in 2018-19, before the pandemic, and 40 360 in 2020-21, during the pandemic. During the pandemic there was a significant reduction in the risk of disease caused by S pneumoniae (risk ratio 0·47; 95% CI 0·40-0·55), H influenzae (0·51; 0·40-0·66) and N meningitidis (0·26; 0·21-0·31), while no significant changes were observed for S agalactiae (1·02; 0·75-1·40), which is not transmitted via the respiratory route. No major changes in the distribution of cases were observed when stratified by patient age or serotype or group. An estimated 36 289 (95% prediction interval 17 145-55 434) cases of invasive bacterial disease were averted during the first 2 years of the pandemic among IRIS-participating countries and territories. INTERPRETATION: COVID-19 containment measures were associated with a sustained decrease in the incidence of invasive disease caused by S pneumoniae, H influenzae, and N meningitidis during the first 2 years of the pandemic, but cases began to increase in some countries towards the end of 2021 as pandemic restrictions were lifted. These IRIS data provide a better understanding of microbial transmission, will inform vaccine development and implementation, and can contribute to health-care service planning and provision of policies. FUNDING: Wellcome Trust, NIHR Oxford Biomedical Research Centre, Spanish Ministry of Science and Innovation, Korea Disease Control and Prevention Agency, Torsten Söderberg Foundation, Stockholm County Council, Swedish Research Council, German Federal Ministry of Health, Robert Koch Institute, Pfizer, Merck, and the Greek National Public Health Organization.
