Acta microbiologica et immunologica Hungarica最新文献

Cutaneous Leishmaniasis (CL) is one of the world's neglected diseases which is caused by Leishmania spp. The aim of this study was to assess molecular profile and antimony resistance of Leishmania isolated from human and rodent hosts. Samples were collected from suspected CL patients referred to health centres and wild rodent's traps in Gonbad-e-Qabus region, north-eastern Iran. Smears were subjected to PCR-RFLP to identify Leishmania species. In addition, ITS1-PCR products were sequenced for phylogenetic analysis. Clinical isolates and rodent samples were subjected to MTT assay to determine IC50 values and in vitro susceptibilities. Expression levels of antimony resistance-related genes were determined in CL isolates. Out of 1,949 suspected patients with CL and 148 rodents, 1,704 (87.4%) and 6 (4.05%) were positive with direct smear, respectively. Digestion patterns of BusRI (HaeIII) endonuclease enzyme were similar to what expected for Leishmania major. Phylogenetic analysis revealed that the highest interspecies similarity was found between current L. major sequences with L. major obtained from Russia and Uzbekistan. Out of 20 L. major samples tested, 13 (65%) were resistant to meglumine antimoniate (MA) treatment, with an activity index (AI) exceeding 4. The remaining 7 samples (35%) responded to MA treatment and were classified as sensitive isolates, with a confirmed sensitive phenotype based on their AI values. The comparison expression analysis of three major antimony resistance-associated genes in unresponsive clinical isolates demonstrated significant fold changes for TDR1 (4.78-fold), AQP1 (1.3-fold), and γ-GCS (1.17-fold) genes (P < 0.05). Herein, we demonstrate genetic diversity and antimony resistance of L. major isolated from human and reservoir hosts in north-eastern Iran, which could be the basis for planning future control strategies.

We report a case of exposure to Coxiella burnetii in a surgical nurse who underwent an injury of her finger with a scalpel blade during a native aortic valve replacement with a bio-prosthetic cardiac valve conducted on a patient suffering from C. burnetii aortic endocarditis. Given the positivity of C. burnetii culture and PCR from the patient's aortic valve, she was prescribed prophylactic doxycycline 100 mg twice a day for 10 days. Q fever is an occupational zoonosis resulting usually of exposure to infected animals by inhalation of infected aerosols or consumption of contaminated raw milk. Apart from materno-foetal transmission, about 180 cases of human-to-human C. burnetii transmission have been published from 1949 to today, including transmission by blood transfusion, sexual relations, transmission in the healthcare setting to staff, patient attendants and other patients that were likely infected from inhalation of aerosol from respiratory or placental products, transmission to staff during autopsies of patients with Q fever and transmission in familial settings. As C. burnetii is a highly infectious bacterium, that may cause infection with a low inoculum, it should be added to the list of organisms which may be of concern following blood exposure among healthcare professionals.

Klebsiella pneumoniae is a major human pathogen, because it causes both community- and hospital-acquired infections. Several multidrug-resistant high-risk clones of K. pneumoniae have been reported worldwide, and these are responsible for high numbers of difficult-to-treat infections. In Greece, a K. pneumoniae ST39 high-risk clone was detected in 2019 in a survey of carbapenem- and/or colistin-resistant Enterobacteriacae. The present study included nine carbapenem-resistant K. pneumoniae (CRKP) isolates collected during a retrospective analysis from October 2020 to December 2020. They were isolated from nine different patients hospitalized in the intensive care unit (ICU) of a hospital in Volos, Greece, and they were selected for analysis due to their phenotypic profile. In this study, we analyzed A165 strain K. pneumoniae ST39 isolated from a blood culture in November 2020. Whole-genome sequencing (WGS) was performed using Ion Torrent Platform, and resistance genes, virulence determinants, capsular types, insertion sequences, phage regions, and clustered regularly interspaced palindromic repeats (CRISPR) regions were detected by bioinformatic analysis. The molecular characterization revealed antimicrobial resistance genes, including sul2 for sulfamethoxazole; dfrA1 for trimethoprim; blaVIM-1 and blaKPC-2 for carbapenems; aac(6')-II for aminoglycosides; fosA for fosfomycin and aad1 for streptomycin, blaSHV-40, blaSHV-85, blaSHV-79, blaSHV-56, and blaSHV-89 for beta-lactams. Point mutations were identified in ompK36, and ompK37 and in acrR, gyrA, parC. Several replicons were found, including CoIRNA, IncC, IncFIB(K), IncFIB(pQiL), and IncFII(K). The capsular typing revealed that the strain was KL23, O2afg. The genome sequence of A165 was submitted to NCBI under PRJNA1074377 and have been assigned to Genbank accession number JAZIBV000000000.

Carbapenems are considered to be among the last line antibiotics against extended-spectrum β-lactamase producing Enterobacterales. Carbapenem-resistant Klebsiella pneumoniae (CRKP) has been frequently reported and its spread in Europe is indisputable and poses an enormous threat to hospitalized patients which is of growing concern. This review aims to record prevalence of CRKP in the Balkan region and to review the current knowledge about this life-threatening pathogen. In this review, we summarize data about clinical isolates of carbapenem-resistant K. pneumoniae from Greece, Croatia, Romania, Bulgaria, Serbia, Slovenia, Montenegro, Bosnia-Herzegovina and Albania from published reports between 2000 and 2023. Among Balkan countries, Greece and Romania are the ones with the most reports about CRKP. Since 2007, KPCs are the dominant carbapenemases in both countries. KPC-2 and NDM-1-producing K. pneumoniae strains have been identified as the most frequent CRKP in Croatia, Bulgaria, Serbia, and Slovenia. OXA-48 enzyme has been identified in most Balkan countries. In addition, since 2018, CRKP sequence type 11 (ST11) seems to have replaced ST258 in Balkan Peninsula, while ST15 continues to thrive throughout the years. Not only efficacy of colistin against CRKP has decreased dramatically during the last ten years but colistin resistance mechanism is based on alterations of chromosomal mgrB gene, rather than the already known mcr genes.Moreover, ceftazidime-avibactam-resistant CRKP were detected mostly in Greece. Emergence of CRKP poses a severe threat to the Balkan countries. Due to the narrow therapeutic window, it is essential to prevent the spread of multiresistant K. pneumoniae strains.

Carbapenem resistant Enterobacteriaceae (CRE) are major human pathogens because, these cause high number of difficult-to-treat infections. Allogeneic hematopoietic stem cell transplant (AHSCT) recipients are highly exposed to these type of bacteria. The aim of our study was to investigate prevalence of CRE colonization in AHSCT patients and to determine genes encoding carbapenem resistance. A retrospective study conducted between January 2015 and December 2019, involved 55 patients colonized with CRE strains. We determined the rate of antibiotic resistance according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the carbapenem resistance genes by PCR assays for genes encoding most frequent β-lactamases namely, blaGES, blaKPC, blaIMI, blaNDM, blaVIM, blaIMP and blaOXA-48. Eighty-one episodes of CRE colonization were recorded in 55 patients, mainly suffering from acute leukaemia (30%) and aplastic anemia (26%). History of hospitalization was noted in 80 episodes. Prior antibiotic treatment, severe neutropenia and corticosteroid therapy were respectively found in 94%, 76% and 58% of cases. Among the 55 patients, six patients (11%) developed a CRE infection. The CRE responsible for colonization were carbapenemase producers in 90% of cases. They belonged mostly to Klebsiella pneumoniae (61/81) and Escherichia coli species (10/81). Antibiotic resistance rates were 100% for ertapenem, 53% for imipenem, 42% for amikacin, 88% for ciprofloxacin and 27% for fosfomycin. Molecular study showed that blaOXA-48 gene was the most frequent (60.5%), followed by blaNDM (58%). Thirty-five (43%) strains were co-producers of carbapenemases. In our study, we report a high rate of CRE intestinal colonization in AHSCT recipients of our center.

In endemic regions, tuberculosis in children constitutes a bigger fraction of total cases as compared to those in low endemic regions, regardless of the implications, this phenomenon has been historically neglected. Pediatric tuberculosis has an insidious onset and quickly develops into disseminated disease and the young are at a special risk for dissemination. Some studies suggest that measures to contain adult tuberculosis are not enough to manage tuberculosis in children, meaning that pediatric tuberculosis needs dedicated attention. Children are harder to diagnose than adults, because collecting samples is difficult, and their bacterial yield is low. In endemic countries, such as Mexico, where contact with Mycobacterium tuberculosis is common, immunological tests are inconsistent, especially in immunocompromised children. With the disruption of Mexican healthcare services by the COVID-19 pandemic, there is an uncertainty of how the situation has evolved, current data about tuberculosis indicates a drop in the national report of cases: 15.4 per 100,000 persons in 2021, compared with pre-COVID 2019 17.7 per 100,000 persons, a small increase in mortality: 1.7 per 100,000 in 2021 compared with 2019 1.6 per 100,000, a drop in treatment success: 80.4% in 2021 compared with 85.4% in 2019, and a decrease in national vaccination rates: an estimate of 86.6% children between 1 and 2 years-old were vaccinated in 2021 compared with 97.3% reported national rate in 2018-2019. There is a need for new research on regions with high tuberculosis incidence, to clarify the current situation of pediatric tuberculosis and improve epidemiological surveillance.

Diarrheal diseases are of great concern worldwide and are responsible for considerable morbidity and mortality. This study investigated the epidemiology and the antibiotic susceptibility of bacterial enteropathogens among diarrheal patients of all ages in Crete, Greece during 2011-2022. Stool specimens were tested by conventional cultural methods for Salmonella, Shigella, Campylobacter, diarrheagenic Escherichia coli (EPEC, STEC), Yersinia enterocolitica, Aeromonas species and Clostridioides difficile. Antimicrobial susceptibility was determined by the disk diffusion method for Enterobacterales, Campylobacter and Aeromonas, and by the gradient diffusion method for C. difficile. Of the 26,060 stool samples from patients of any age, 1,022 (3.9%) were positive for bacterial enteropathogens. Campylobacter spp. were the most commonly isolated bacteria (56.4%), followed by Salmonella enterica (32.3%), and E. coli (EPEC, STEC) (6.5%). Toxigenic C. difficile was isolated from 341 out of 8,848 diarrheal specimens examined (3.9%). Resistance to ampicillin was observed in 12.4% of Salmonella, 66.7% of Shigella and 34.8% of E. coli (EPEC, STEC) isolates. Resistance to trimethoprim/sulfamethoxazole was observed in 5.8% of Salmonella, 33.3% of Shigella, and 15.1% of E. coli (EPEC, STEC) isolates. High rates of ciprofloxacin resistance (77.3%) were detected among Campylobacter isolates, while resistance to erythromycin was observed in 2.4% of them. All C. difficile isolates were susceptible to vancomycin and metronidazole. Our findings suggest declining trends in prevalence of bacterial enteropathogens, except for Campylobacter spp. and changes in the susceptibility rates to antimicrobials. Continuous surveillance of prevalence and antimicrobial susceptibility of bacterial enteropathogens is mandatory for implementing targeted and effective prevention and infection control measures.

Hypervirulent Klebsiella pneumoniae is an emerging pathogen that has gained attention due to its increased ability to cause infections even in healthy individuals. The aim of this study is to investigate virulence factors in K. pneumoniae strains isolated from clinical specimens and their association with carbapenem resistance. The study was conducted on 260 isolates identified between 2018 and 2023 at the Mohammed V Military Teaching Hospital in Rabat, Morocco. The isolates were categorized based on their susceptibility to antibiotics. The hypermucoviscosity was determined by a string test, while the presence of capsular serotypes and virulence genes were identified by PCR. Among our strains, 6.2% (n = 16) exhibited hypervirulent characteristics, 56% were resistant to carbapenem. Notably, 5.7% (n = 6) of carbapenem-resistant isolates expressed the hypermucoviscous phenotype, while 1.5% (n = 2) of carbapenem-susceptible K. pneumoniae isolates exhibited the same trait. In our study, we found that a total of 10 isolates (3.8%) had virulent capsular serotypes, with K2 being the most prevalent 40% (n = 4) and K20 in 30% (n = 3). Furthermore, we detected the presence of the Aerobactin gene in 1.5% (n = 4) of the isolates examined. Based on our findings, it appears that there was no correlation between the presence of virulence factors and carbapenem resistance. In conclusion, identifying hypervirulent K. pneumoniae in clinical specimens and assessing their antibiotic resistance profiles are crucial to ensure effective therapy and to prevent outbreaks.