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Oxygen tolerance of anaerobes is a virulence factor, but can also be a beneficial property. Many species have evolved to tolerate or take advantage of the presence of low, especially nanaerobic (≤0.14 %) oxygen concentrations. Oxygen tolerance is genus-, species- and strain-dependent according to their protective mechanisms. It was better expressed in some pathogenic species such as Bacteroides fragilis, Clostridioides difficile, and Clostridium perfringens, as well as in Akkermansia muciniphila than in other potential probiotics such as Alistipes, Blautia and Roseburia spp. Different degrees of oxygen sensitivity were found between the strains of Anaerostipes, Faecalibacterium, and Bifidobacterium spp. Importantly, clostridial spores and anaerobes in biofilms are protected from oxidation. Rubrerythrins and flavodiiron proteins and two regulators (sigma factor B and PerR) contribute to C. difficile protection from reactive oxygen species (ROS). The frequent pathogen, B. fragilis, has numerous protective factors such as enzymes (catalase, superoxide dismutase, alkyl hydroperoxidase, thioredoxin peroxidase, and aerobic-type NrdAB ribonucleotide reductase), and nanaerobic respiration. Seven proteins confer strain-specific oxygen adaptation of Faecalibacterium prausnitzii. Oxygen tolerance protects anaerobes from ROS, shields their DNA and modulates gene expression. Furthermore, oxygen can induce mutations leading to antibiotic resistance as shown in Prevotella melaninogenica. Some Faecalibacterium, Anaerostipes, Bifidobacterium, and Akkermansia strains from the intestinal microbiota exhibiting oxygen tolerance may become next-generation probiotic candidates. Further studies are needed to reveal oxygen effects on more anaerobic species and strains, and the influence of oxygen on antibiotic resistance. More studies on oxygen-tolerant probiotic strains can be useful to optimize biotechnological methods.
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The rapid spread of carbapenemase-producing strains has led to increased levels of resistance among Gram-negative bacteria, especially enterobacteria. The current study aimed to collect and genetically characterize the colistin- and carbapenem-resistant isolates, obtained in one of the biggest hospitals (Military Medical Academy) in Sofia, Bulgaria. Clonal relatedness was detected by RAPD and MLST. Carbapenemases, ESBLs, and mgrB were investigated by PCR amplification and sequencing, replicon typing, and 16S rRNA methyltransferases with PCRs. Fourteen colistin- and carbapenem-resistant K. pneumoniae isolates were detected over five months. Six carbapenem-resistant and colistin-susceptible isolates were also included. The current work revealed a complete change in the spectrum of carbapenemases in Bulgaria. blaNDM-5 was the only NDM variant, and it was always combined with blaOXA-232. The coexistence of blaOXA-232 and blaNDM-5 was observed in 10/14 (72%) of colistin- and carbapenem-resistant K. pneumoniae isolates and three colistin-susceptible isolates. All blaNDM-5- and blaOXA-232-positive isolates belonged to the ST6260 (ST101-like) MLST type. They showed great mgrB variability and had a higher mortality rate. In addition, we observed blaOXA-232 ST14 isolates and KPC-2-producing ST101, ST16, and ST258 isolates. The colistin- and carbapenem-resistant isolates were susceptible only to cefiderocol for blaNDM-5- and blaOXA-232-positive isolates and to cefiderocol and ceftazidime/avibactam for blaOXA-232- or blaKPC-2-positive isolates. All blaOXA-232-positive isolates carried rmtB methylase and the colE replicon type. The extremely limited choice of appropriate treatment for patients infected with such isolates and their faster distribution highlight the need for urgent measures to control this situation.
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Non-antibiotic adjuncts may improve Helicobacter pylori infection control. Our aim was to emphasize curcumin benefits in controlling H. pylori infection. We discussed publications in English mostly published since 2020 using keyword search. Curcumin is the main bioactive substance in turmeric. Curcumin inhibited H. pylori growth, urease activity, three cag genes, and biofilms through dose- and strain-dependent activities. Curcumin also displayed numerous anticancer activities such as apoptosis induction, anti-inflammatory and anti-angiogenic effects, caspase-3 upregulation, Bax protein enhancement, p53 gene activation, and chemosensitization. Supplementing triple regimens, the agent increased H. pylori eradication success in three Iranian studies. Bioavailability was improved by liposomal preparations, lipid conjugates, electrospray-encapsulation, and nano-complexation with proteins. The agent was safe at doses of 0.5->4 g daily, the most common (in 16% of the users) adverse effect being gastrointestinal upset. Notably, curcumin favorably influences the intestinal microbiota and inhibits Clostridioides difficile. Previous reports showed the inhibitory effect of curcumin on H pylori growth. Curcumin may become an additive in the therapy of H. pylori infection, an adjunct for gastric cancer control, and an agent beneficial to the intestinal microbiota. Further examination is necessary to determine its optimal dosage, synergy with antibiotics, supplementation to various eradication regimens, and prophylactic potential.
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Antibacterianos , Curcuma , Curcumina , Infecções por Helicobacter , Helicobacter pylori , Curcumina/farmacologia , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/microbiologia , Helicobacter pylori/efeitos dos fármacos , Helicobacter pylori/genética , Humanos , Antibacterianos/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacosRESUMO
Background and Objective: Klebsiella pneumoniae appears to be a significant problem due to its ability to accumulate antibiotic-resistance genes. After 2013, alarming colistin resistance rates among carbapenem-resistant K. pneumoniae have been reported in the Balkans. The study aims to perform an epidemiological, clinical, and genetic analysis of a local outbreak of COLr CR-Kp. Material and Methods: All carbapenem-resistant and colistin-resistant K. pneumoniae isolates observed among patients in the ICU unit of Military Medical Academy, Sofia, from 1 January to 31 October 2023, were included. The results were analyzed according to the EUCAST criteria. All isolates were screened for blaVIM, blaIMP, blaKPC, blaNDM, and blaOXA-48. Genetic similarity was determined using the Dice coefficient as a similarity measure and the unweighted pair group method with arithmetic mean (UPGMA). mgrB genes and plasmid-mediated colistin resistance determinants (mcr-1, mcr-2, mcr-3, mcr-4, and mcr-5) were investigated. Results: There was a total of 379 multidrug-resistant K. pneumoniae isolates, 88% of which were carbapenem-resistant. Of these, there were nine (2.7%) colistin-resistant isolates in six patients. A time and space cluster for five patients was found. Epidemiology typing showed that two isolates belonged to clone A (pts. 1, 5) and the rest to clone B (pts. 2-4) with 69% similarity. Clone A isolates were coproducers of blaNDM-like and blaOXA-48-like and had mgrB-mediated colistin resistance (40%). Clone B isolates had only blaOXA-48-like and intact mgrB genes. All isolates were negative for mcr-1, -2, -3, -4, and -5 genes. Conclusions: The study describes a within-hospital spread of two clones of COLr CR-Kp with a 60% mortality rate. Clone A isolates were coproducers of NDM-like and OXA-48-like enzymes and had mgrB-mediated colistin resistance. Clone B isolates had only OXA-48-like enzymes and intact mgrB genes. No plasmid-mediated resistance was found. The extremely high mortality rate and limited treatment options warrant strict measures to prevent outbreaks.
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Colistina , Infecções por Klebsiella , Humanos , Colistina/farmacologia , Colistina/uso terapêutico , Klebsiella pneumoniae/genética , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/epidemiologia , Farmacorresistência Bacteriana/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Carbapenêmicos/uso terapêutico , Hospitais , beta-Lactamases/genéticaRESUMO
To solve the problem with pan-drug resistant and extensively drug-resistant Gram-negative microbes, newly approved drugs such as ceftazidime/avibactam, cefiderocol, plazomicin, meropenem/vaborbactam, and eravacycline have been introduced in practice. The aim of the present study was to collect carbapenemase-producing clinical Enterobacterales isolates, to characterize their carbapenemase genes and clonal relatedness, and to detect their susceptibility to commonly used antimicrobials and the above-mentioned newly approved antibiotics. Sixty-four carbapenemase producers were collected in a period of one year from four Bulgarian hospitals, mainly including Klebsiella pneumoniae (89% of the isolates) and also single Proteus mirabilis, Providencia stuartii and Citrobacter freundii isolates. The main genotype was blaNDM-1 (in 61%), followed by blaKPC-2 (23%), blaVIM-1 (7.8%) and blaOXA-48 (7.8%). Many isolates showed the presence of ESBL (blaCTX-M-15/-3 in 76.6%) and AmpC (blaCMY-4 in 37.5% or blaCMY-99 in 7.8% of isolates). The most common MLST type was K. pneumoniae ST11 (57.8%), followed by ST340 (12.5%), ST258 (6.3%) and ST101 (6.3%). The isolates were highly resistant to standard-group antibiotics, except they were susceptible to tigecycline (83.1%), colistin (79.7%), fosfomycin (32.8%), and aminoglycosides (20.3-35.9%). Among the newly approved compounds, plazomicin (90.6%) and eravacycline (76.3%) showed the best activity. Susceptibility to ceftazidime/avibactam and meropenem/vaborbactam was 34.4% and 27.6%, respectively. For cefiderocol, a large discrepancy was observed between the percentages of susceptible isolates according to EUCAST susceptibility breakpoints (37.5%) and those of CLSI (71.8%), detected by the disk diffusion method. This study is the first report to show patterns of susceptibility to five newly approved antibiotics among molecularly characterized isolates in Bulgaria. The data may contribute to both the improvement of treatment of individual patients and the choice of infection control strategy and antibiotic policy.
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The aim of the study was to evaluate the frequency and characteristics of mixed (multiple-genotype) Helicobacter pylori infections (MGIs) in 155 Bulgarian symptomatic patients (21 children and 134 adults). MGIs were common (36.1%), including double-strain (34.8%) and triple-strain infections (1.3%). None of the 8 ulcer patients harbored multiple subtypes. We detected 18 multiple allelic combinations, of which the most frequent subtypes (17.4%) were vacA s1as2 and vacA s1cs2. The 2 patients with triple-strain infections had vacA s1bs1cs2i1i2/iceA1A2 and vacA s1as1cs2 subtypes. They were both adult men with chronic gastritis and both were examined in 2022. The prevalence of MGIs (51.7%) was 2-fold higher in 2020 to 2022 than in 2015 to 2019 (26.3%). Putative factors for the increase may be the patient's characteristics and COVID-19 pandemic-associated factors. MGI rates corresponded to the high infection seroprevalence (72.4% in 2011) in Bulgaria. The evolution and clinical importance of mixed H. pylori infections merit extensive evaluation.
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Infecções por Helicobacter , Helicobacter pylori , Adulto , Masculino , Criança , Humanos , Proteínas de Bactérias/genética , Antígenos de Bactérias/genética , Helicobacter pylori/genética , Infecções por Helicobacter/epidemiologia , Infecções por Helicobacter/complicações , Bulgária/epidemiologia , Pandemias , Estudos Soroepidemiológicos , GenótipoRESUMO
INTRODUCTION: Updating data on Clostridioides difficile antibiotic resistance is important for treatment improvement of C. difficile infections (CDIs). AREAS COVERED: Results from 20 countries were included. The mean resistance to 2 mg/l vancomycin, 2 mg/l metronidazole, 4 mg/l moxifloxacin, and 4 mg/l clindamycin was 4.7% (0 to ≥ 26% in two studies), 2.6% (0 to ≥ 40% in 3 studies), 34.9% (6.6->80%), and 61.0% (30->90%), respectively. Resistance to erythromycin (>60-88%), rifampin (>23-55.0%), imipenem (0.6 to > 78% in a clone), tigecycline (0-<5.0%), and fidaxomicin (0-2%) was also found. Resistance to ≥ 5 antibiotics of different classes was reported in some countries. High resistance and multidrug resistance were observed in hypervirulent and epidemic strains. Although only 1% of COVID-19 patients had CDIs, the proportion might be underestimated. EXPERT OPINION: C. difficile antimicrobial susceptibility varied by country/region, study period, and circulating ribotypes. For CDI treatment, fidaxomicin (preferably) or vancomycin is recommended, while metronidazole is suitable for mild infections. New approaches, including biotherapeutics (Rebyota), strains, antibiotics (ridinilazole and ibezapolstat), and monoclonal antibodies/cocktails merit further evaluation. Because of the resistance rate variations, C. difficile antibiotic susceptibility should be regularly monitored. Post-COVID-19 resistance should be separately presented. Some discrepancies between vancomycin and metronidazole results need to be clarified.
Clostridioides difficile can cause mild to dangerous diarrhea in people following antibiotic use. Many antibacterial agents can cause diseases. However, treatment is limited to three antibiotics. The study of resistance to them is important for improving the treatment of infections. The study of resistance to other antibiotics helps to understand the spread and risks of infections. We discussed data about C. difficile antibiotic resistance from 20 countries according to recent publications. For the treatment of C. difficileinfections, fidaxomicin is the drug of choice with 02% resistance to it. Resistance to the two other antibiotics used to treat infections is less than 5% of isolates. Much higher resistance was found to antibiotics that can cause C. difficile infections such as ciprofloxacin, clindamycin, ceftriaxone, erythromycin, and others. The resistance varies according to the country, patients' groups, years of study, and circulating strains. The resistance was high in hypervirulent and epidemic strains. In some studies, there was resistance to 5 and 6 antibiotics of different classes. Antibiotic use and incidence of infections during the COVID-19 pandemic varied. However, the evolution of C. difficile infection during the pandemic has yet to be determined.
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With the buildup of new research data, newer associations between anaerobic bacteria and diseases/conditions were evaluated. The aim of the mini-review was to draw attention and to encourage further multidisciplinary studies of the associations. We considered microbiome-disease correlations such as a decrease of fecal Faecalibacterium prausnitzii abundance in inflammatory bowel disease (IBD) and IBD recurrence, suggesting that F. prausnitzii could be a good biomarker for IBD. A link of subgingival Porphyromonas gingivalis with cardiovascular diseases was reported. Decreased Roseburia abundance was observed in the gut of Alzheimer's and Parkinson's disease patients. Akkermansia muciniphila was found to improve adipose/glucose metabolism, however, its intestinal abundance was observed in neurodegenerative diseases as well. Severe Clostridioides difficile infections have been reported in neonates and young children. Carcinogenic potential of anaerobes has been suggested. Fusobacterium nucleatum was implicated in the development of oral and colorectal cancer, Porphyromonas gingivalis and Tannerella forsythia were linked to esophageal cancer and Cutibacterium acnes subsp. defendens was associated with prostate cancer. However, there are some controversies about the results. In a Swedish longitudinal study, neither P. gingivalis nor T. forsythia exhibited oncogenic potential. The present data can enrich knowledge of anaerobic bacteria and their multifaceted significance for health and disease and can draw future research directions. However, more studies on large numbers of patients over prolonged periods are needed, taking into account the possible changes in the microbiota over time.
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Doenças Inflamatórias Intestinais , Microbiota , Doenças não Transmissíveis , Masculino , Criança , Recém-Nascido , Humanos , Pré-Escolar , Bactérias Anaeróbias , Estudos Longitudinais , Doenças Inflamatórias Intestinais/microbiologia , Porphyromonas gingivalisRESUMO
Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacterium. The clinical features of C. difficile infections (CDIs) can vary, ranging from the asymptomatic carriage and mild self-limiting diarrhoea to severe and sometimes fatal pseudomembranous colitis. C. difficile infections (CDIs) are associated with disruption of the gut microbiota caused by antimicrobial agents. The infections are predominantly hospital-acquired, but in the last decades, the CDI patterns have changed. Their prevalence increased, and the proportion of community-acquired CDIs has also increased. This can be associated with the appearance of hypervirulent epidemic isolates of ribotype 027. The COVID-19 pandemic and the associated antibiotic overuse could additionally change the patterns of infections. Treatment of CDIs is a challenge, with only three appropriate antibiotics for use. The wide distribution of C. difficile spores in hospital environments, chronic persistence in some individuals, especially children, and the recent detection of C. difficile in domestic pets can furthermore worsen the situation. "Superbugs" are microorganisms that are both highly virulent and resistant to antibiotics. The aim of this review article is to characterise C. difficile as a new member of the "superbug" family. Due to its worldwide spread, the lack of many treatment options and the high rates of both recurrence and mortality, C. difficile has emerged as a major concern for the healthcare system.
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Antibiotic resistance among Helicobacter pylori strains is the major cause of eradication failure. Resistance prevalence is dynamic and can greatly vary among countries over the years. We revealed H. pylori resistance trends for five antibiotics in 14 countries through articles predominantly published in 2018-2022, since the latest data can best show the most recent trends in resistance evolution. Amoxicillin resistance generally exhibited no evolution, yet it increased in Bulgaria, Iran, China, and Vietnam. Metronidazole resistance exhibited different trends, including an increase, a decrease and no evolution in six, three, and five studies, respectively. Clarithromycin resistance increased in Australia, Belgium, Bulgaria, Italy, Iran, and Taiwan, but remained stable in France, Spain, Russia, China, Chile, and Colombia. Tetracycline resistance was low and stable except in Iran. Levofloxacin resistance increased in four European and six other countries/regions, without significant increases in France, Spain, and Chile. In Chile, triple resistance also increased. In countries such as France and Spain, resistance to most antibiotics was stabilized, while in Bulgaria, Belgium, Iran and Taiwan, resistance to three or more agents was reported. Use of non-recommended regimens, national antibiotic consumption, patient's compliance, host factors, strain virulence, migrations, and azithromycin overuse during the COVID-19 pandemic can influence resistance evolution. New drugs, eradication regimens and diagnostic methods, such as next-generation sequencing can improve H. pylori infection control.
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Prevalence of antibiotic resistant Helicobacter pylori was compared between 50 patients living outside the capital city and 50 matched pairs of capital city residents (CCRs). H. pylori isolates from 2018 to 2022 were included. Resistance rates in CCRs and those living elsewhere were 4.0 and 6.0% to amoxicillin, 48.0 and 42.0% to metronidazole, 30 and 30% to clarithromycin, and 4.0 and 4.0% to tetracycline, respectively. Levofloxacin resistance was higher (38.0%) in the capital city vs 20.0% (P = 0.047) in the country. Odd ratio for levofloxacin resistance between pair-matched groups was 2.45 (95% CI, OR 1.0-6.02, P value = 0.05) and relative risk for fluoroquinolone resistance was 1.90 (95% CI for RR 0.98-3.67) for CCRs vs residents in other regions. Resistance rates to levofloxacin and clarithromycin were worryingly high in our study, most probably due to the high quinolone consumption (2.86 DDD/day in 2017) in Bulgaria and the increase in macrolide, lincosamide and streptogramin consumption, especially of azithromycin, by >42% with the start of COVID-19 pandemic. Briefly, antibiotic resistance of H. pylori has a dynamic change, and it can display different patterns in certain geographic regions. The results imply that antibiotic consumption should be carefully controlled and unjustified use of levofloxacin should be restricted, especially in some large cities. Antibiotic policy should be further strengthened and regular monitoring of resistance in various geographic regions is needed for treatment optimization.
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COVID-19 , Infecções por Helicobacter , Helicobacter pylori , Humanos , Claritromicina , Levofloxacino , Infecções por Helicobacter/epidemiologia , Bulgária , Pandemias , Farmacorresistência Bacteriana , COVID-19/epidemiologia , Antibacterianos/farmacologia , Amoxicilina , Metronidazol , Testes de Sensibilidade MicrobianaRESUMO
The gastrointestinal tract is an important reservoir of high-risk Enterobacteria clones and a driver of antimicrobial resistance in hospitals. In this study, patients from six hospitals in four major Bulgarian towns were included in this study. Overall, 205 cefotaxime-resistant isolates (35.3%) of Enterobacterales order were detected in fecal samples among 580 patients during the period of 2017-2019. ESBL/carbapenemase/plasmidic AmpC producer rates were 28.8%, 2.4%, and 1.2%, respectively. A wide variety of ESBLs: CTX-M-15 (41%), CTX-M-3 (24%), CTX-M-27 (11%), and CTX-M-14 (4%) was found. The carbapenemases identified in this study were New Delhi metalo-ß-lactamase (NDM)-1 (5.4%) and Klebsiella carbapenemase (KPC)-2 (1.5%). Most NDM-1 isolates also produced CTX-M-15/-3 and CMY-4 ß-lactamases. They belonged to ST11 Klebsiella pneumoniae clone. The epidemiology typing revealed three main high-risk K. pneumoniae clones (26%)-ST11, ST258, and ST15 and five main Escherichia coli clones-ST131 (41.7%), ST38, ST95, ST405, and ST69. Sixty-one percent of ST131 isolates were from the highly virulent epidemic clone O25b:H4-ST131. Phylotyping revealed that 69% of E. coli isolates belonged to the virulent B2 and D groups. Almost all (15/16) Enterobacter isolates were identified as E. hormaechei and the most common ST type was ST90. Among all of the isolates, a high ESBL/carbapenemases/plasmid AmpC (32.4%) prevalence was observed. A significant proportion of the isolates (37%) were members of high-risk clones including two pan-drug-resistant K. pneumoniae ST11 NDM-1 producing isolates. Due to extensive antibiotic usage during COVID-19, the situation may worsen, so routine screenings and strict infection control measures should be widely implemented.
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The more frequent usage of colistin resulted in an increase of colistin resistance due to lipopolysaccharide modifications. The aim of this study was to reveal the prevalence and mechanisms of colistin resistance among multidrug-resistant Klebsiella pneumoniae isolates collected in Bulgaria. One hundred multidrug resistant K. pneumoniae isolates were collected in a period between 2017 and 2018. Among them, 29 colistin resistant and 8 heteroresistant isolates were observed and further investigated. Clonal relatedness was detected by RAPD and MLST. Сarbapenemases, two component system phoQ/phoP, pmrA/B, and mgrB were investigated by PCR amplification and Sanger sequencing. Among 37 colistin nonsusceptible isolates, we detected 25 NDM-1 producers. The isolates belonged mainly to ST11 (80%), and also to ST147, ST35, ST340, ST219 (1-2 members per clone). Nine colistin resistant isolates showed changes in mgrB. IS903B-like elements truncated mgrB in five isolates. In two isolates, premature stopcodon (Q30stopcodon) was observed and another two isolates did not amplify mgrB, possibly due to bigger deletion or insertion. No isolates showed phoQ/phoP and pmrA/B mutations except for pmrB (four isolates had R256G). All isolates with IS903B insertions belonged to ST11 clone. The mgrB alterations play major role in colistin resistance in K. pneumoniae isolates studied in the current work. We report truncation of mgrB by IS903 like element in colistin resistant NDM-1 producing K. pneumoniae ST11 clone in Bulgaria.
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Colistina , Infecções por Klebsiella , Humanos , Colistina/farmacologia , Antibacterianos/farmacologia , Klebsiella pneumoniae/genética , Tipagem de Sequências Multilocus , Bulgária/epidemiologia , Técnica de Amplificação ao Acaso de DNA Polimórfico , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Infecções por Klebsiella/epidemiologia , Testes de Sensibilidade Microbiana , beta-Lactamases/genéticaRESUMO
Background: Severe infections of virulent methicillin-resistant Staphylococcus aureus (MRSA) are a serious health problem. The present study aimed to investigate clonal spread, virulence and antimicrobial resistance rates of Bulgarian MRSA isolates in 2016-2020. Methods: Molecular identification and mecA gene detection were performed with PCR. Clonal relatedness was evaluated by RAPD PCR and MLST. MRSA epidemiology, virulence and resistance patterns were investigated by PCR. Results: All 27 isolates were identified as S. aureus and were mecA positive, and all were susceptible to linezolid, tigecycline and vancomycin. The toxin genes hlg (in 92.6% of isolates), seb (77.8%), sei (77.8%), seh (59.3%), sej (55.6%), and seg (48.1%), were frequently found among the isolates. Epidemiological typing by RAPD identified 4 clones (16 isolates) and 11 were with a unique profile. MLST analysis of the same MRSA isolates showed five MLST clonal complexes and 11 ST types, including CC5 (33.3%) (ST5, ST221, ST4776), CC8 (22.2%) (ST8, ST239, ST72), CC15 (ST582), CC22 (14.8%) (ST217, ST5417), CC30 (ST30) CC398 (ST398), and CC59 (ST59). The isolates from CC5 showed higher virulence potential and almost all were macrolide resistant (ermB or ermC positive). CC8 isolates showed higher level of resistance. Conclusion: To the best of our knowledge, this study is the first describing the clonal spreading of Bulgarian MRSA and the association with their virulence and resistance determinants. Monitoring of MRSA epidemiology, resistance and virulence profile can lead to better prevention and faster therapeutic choice in cases of severe infections.
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Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus , Epidemiologia Molecular , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Virulência/genética , Tipagem de Sequências Multilocus , Técnica de Amplificação ao Acaso de DNA Polimórfico , Bulgária/epidemiologia , Infecções Estafilocócicas/epidemiologia , Farmacorresistência Bacteriana , Testes de Sensibilidade MicrobianaRESUMO
Helicobacter pylori resistance to amoxicillin has usually been rare. We traced resistance evolution in 474 strains over 15 years. Although minimum inhibitory concentrations MIC50 and MIC90 were similar among subgroups, the overall resistance rate (MICs, >0.125-3 mg/L) significantly increased from 4.2% in 2007-2014 to 8.9% in 2015-2021.
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Infecções por Helicobacter , Helicobacter pylori , Amoxicilina/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bulgária , Claritromicina/farmacologia , Infecções por Helicobacter/tratamento farmacológico , Humanos , Metronidazol/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
Antibiotic resistance of Helicobacter pylori strains from 106 symptomatic children was evaluated according to EUCAST breakpoints and rate of multidrug resistance (MDR) was analyzed. Overall resistance rates were amoxicillin 7.5%, metronidazole 25.5%, clarithromycin 34.0% and ciprofloxacin 14.1%. There were no significant differences in resistance rates according to patients' age (2-6 and 7-18 years) and sex. Combined resistance rate was 19.8%, including double, triple, and quadruple resistance in 13.2% (14 strains), 5.7% (6) and 0.9% (1) of the strains, respectively. MDR was found in 5.9% (5/84) of the children with gastritis and in two of the four children with celiac disease. The MDR was present in three children aged 4-6 years and in four children aged 10-17 years. The total MDR rate (6.6%) in Bulgarian children in 2012-2021 was higher than those in other studies based on EUCAST breakpoints such as those in pediatric patients in Slovenia in 2011-2014 (3.8%), Lithuania in 2013-2015 (0%) and Spain in 2014-2019 (0%), although being lower than those (20.7% in the untreated and 47.0% in the treated children) in China in 2019. In brief, it is of concern that MDR can strongly limit the choice of H. pylori therapy of one out of fifteen Bulgarian children and that overall resistance to both metronidazole and clarithromycin can hinder the treatment of 15.1% of the pediatric patients. Susceptibility-guided tailored eradication therapy of H. pylori infection should be more frequently implemented in the symptomatic children to avoid risks of both the infection itself and multiple antibiotic treatments.
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Anaerobic cocci are common anaerobic isolates. Numerous genera of anaerobic cocci have been reported in both urinary tract microbiota, mainly of females, and in cases of urinary tract infections (UTIs), predominantly in patients with comorbidities, when no facultatively anaerobic bacteria were detected from the urine samples. UTIs caused by anaerobic cocci have been reported in >7% in some studies. As the routine diagnostic methods may be insufficient to detect and identify the anaerobic cocci in patients with UTIs, enhanced quantitative urine culture (EQUC) can give better results. EQUC is performed by plating urine samples onto different media to be incubated in both aerobic and anaerobic conditions with a prolonged incubation time. Other newer methods such as 16S rRNA gene sequencing, qualitative PCR and Next Generation Sequencing can also be considered. Anaerobic cocci such as Peptoniphilus, Parvimonas, Anaerococcus and Finegoldia spp. were found in patients with bacteremia of urinary source. A fatal outcome has been reported in a diabetic patient with emphysematous pyelonephritis caused by Finegoldia magna and Candida parapsilosis due to a delay in seeking hospital care during the COVID-19 pandemic. In specific cases such as of chronic infections, immunosuppression, comorbidity, advanced age, following urological tract manipulations and negative culture results for usual uropathogens, it may be advisable to use suprapubic aspiration cultured in both aerobic and anaerobic condition or EQUC using media which support the relative slow growing anaerobic cocci as well.
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COVID-19 , Infecções Urinárias , Feminino , Humanos , Bactérias Anaeróbias/genética , RNA Ribossômico 16S/genética , Anaerobiose , Pandemias , Infecções Urinárias/diagnóstico , Infecções Urinárias/microbiologiaRESUMO
Gardnerella vaginalis in association with anaerobes has been linked to bacterial vaginosis in women, while urinary tract infections (UTIs) in men have rarely been reported. The aim of the review was to reveal the significance of G. vaginalis UTIs in men. Prevalence of G. vaginalis UTIs in men varied from 0.5 to >27% according to patients' groups. Most patients had comorbidity such as urolithiasis or stents, transplants, tumors and diabetes, however, infections can also affect immunocompetent patients. We observed G. vaginalis-associated bacteriuria and leukocyturia in a kidney transplant man. Complications of the UTIs such as bacteremia (in 9/11 cases), hydronephrosis (4/11) and abscesses or septic emboli have been reported. Bacterial vaginosis in female partners has been a risk factor for UTIs in males. In women, biofilm Gardnerella phenotype, stabilized by Atopobium vaginae and Prevotella bivia was linked to ≥6-fold higher antibiotic resistance rates compared with the planktonic phenotype. Non-susceptibility to metronidazole and levofloxacin was found also in males. Therefore, if aerobic urine cultures are negative, urine and blood samples from male patients with predisposing factors and clinical signs of UTIs and bacteremia, can be taken. Plates should be incubated for 2-4 days in capnophilic/microaerophilic conditions, however only anaerobic incubation can help with detecting G. vaginalis strains which grow only anaerobically. Susceptibility testing of the isolates is highly important. Briefly, adherent G. vaginalis phenotype can be sexually transmissible. Despite the infrequency of G. vaginalis UTIs in men, the infections should be considered since they are often linked to severe complications.
Assuntos
Gardnerella vaginalis , Infecções por Bactérias Gram-Positivas/microbiologia , Infecções por Bactérias Gram-Positivas/transmissão , Infecções Urinárias/microbiologia , Gerenciamento Clínico , Suscetibilidade a Doenças , Feminino , Gardnerella vaginalis/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/diagnóstico , Infecções por Bactérias Gram-Positivas/epidemiologia , Humanos , Masculino , Prevalência , Fatores de Risco , Fatores Sexuais , Doenças Bacterianas Sexualmente Transmissíveis/diagnóstico , Doenças Bacterianas Sexualmente Transmissíveis/epidemiologia , Doenças Bacterianas Sexualmente Transmissíveis/microbiologia , Doenças Bacterianas Sexualmente Transmissíveis/transmissão , Infecções Urinárias/diagnóstico , Infecções Urinárias/epidemiologia , Infecções Urinárias/transmissão , Vaginose Bacteriana/microbiologiaRESUMO
The gastrointestinal tract is an important reservoir of extended spectrum beta-lactamase (ESBL)/carbapenemase-producing Enterobacterales isolates. This study included patients from two Bulgarian hospitals. Overall, 98 ESBL producers (including 68 Escherichia coli and 20 Klebsiella pneumoniae isolates) were detected among 99 hospitalized patients, 212 patients at admission, and 92 hospital staff in 42.4%, 24.5%, and 4%, respectively. We observed blaCTX-M-15 in 47% of isolates, blaCTX-M-3 in 39% and blaCTX-M-14 in 11%. Three blaCTX-M-15 positive isolates were also blaKPC-2 positive. High transferability was detected for blaCTX-M-3 carrying plasmids (55%) with L/M and I1 replicon plasmids, followed by CTX-M-14 (36.4%) and CTX-M-15 (27.9%) with IncF plasmids. BlaKPC-2 was carried by FIIAs plasmids. Epidemiology typing revealed 8 K. pneumoniae ST types-ST15(8/20), ST17(4/20), ST37(2/20) and 9 E. coli ST types-ST131 (30.9%, 21/68), ST38 (8/68), ST95(7/68) and ST316(7/68). All ST131 isolates but one was from the highly virulent epidemic clone O25bST131. This is the first report in Bulgaria about ESBL/carbapenemase faecal carriage. We observed high ESBL/carbapenemases prevalence. A predominant number of isolates were members of highly epidemic and virulent PanEuropean clones ST15 K. pneumoniae and O25bST131 E. coli. High antibiotics usage during the COVID pandemic will worsen the situation. Routine screenings and strict infection control measures should be widely implemented.