Pathogens最新文献

Pseudomonas aeruginosa is a leading cause of healthcare-associated infections, which are related to substantial morbidity and mortality. The incidence of Plasmid-Mediated Quinolone Resistance (PMQR) determinants has been previously reported in this bacterium. However, there is limited information regarding the presence of PMQR and carbapenemase-encoding genes simultaneously. This study aims to analyze the prevalence of these determinants on P. aeruginosa strain isolated from clinical patients in the State of Aguascalientes, Mexico. Fifty-two P. aeruginosa isolates from nosocomial patients were collected from Centenario Hospital Miguel Hidalgo. This is a retrospective observational study conducted at a single center. Antibiotic susceptibility was tested using the Vitek-2 system. Only carbapenem-resistant isolates were included in this study. Carbapenemase-encoding genes and PMQR determinants were screened by polymerase chain reaction (PCR). Resistance rates of 100% were found on tigecycline and ceftriaxone. Of the 52 isolates, 34.6% were positive for the qnr genes, 46.2% for the oqxA gene, and 25% for the aac-(6')-lb gene. The most frequent carbapenemase genes found in the samples were bla_OXA-51 (42.3%), bla_OXA-1 (15.4%), and bla_VIM (15.4%). bla_OXA-51 co-carrying oqxA was detected in 21.1% of the isolates, bla_OXA-51 co-carrying aac-(6')-lb in 11.5%, bla_VIM co-carrying aac-(6')-lb in 3.8%, and bla_KPC co-carrying oqxA in 5.8%. Systematic surveillance to detect carbapenemase-encoding genes and PMQR determinants, and rational prescription using the last-line drugs could help in preventing the dissemination of multidrug-resistant determinants.

Which patients should be monitored for coinfections or should receive empirical antibiotic treatment, in patients with an acute viral respiratory infection, is largely unknown. We evaluated the prevalence, characteristics, outcomes of coinfected patients, and risk factors associated with a coinfection among patients with an acute viral infection. A retrospective, single-center study recruited consecutive patients from October 2022 to March 2023 presenting to the emergency department with signs of a respiratory tract infection. Patients were screened for respiratory viruses and bacterial/fungal secondary infections according to local standard procedures. Outcomes included severe disease, in-hospital complications, all-cause in-hospital and ICU-related mortality, time to death, time to discharge, and time to coinfection. The analysis included 652 patients. A viral infection and a secondary bacterial/fungal infection were detected in 39.1% and 40% of cases. Compared with the rest of the cohort, coinfected patients had more frequently severe disease (88.3%, p < 0.001; 51% in patients with SARS-CoV-2) and higher in-hospital mortality (16.5%, p = 0.010). Nephropathy (OR 3.649, p = 0.007), absence of COVID-19 vaccination (OR 0.160, p < 0.001), SARS-CoV-2 infection (OR 2.390, p = 0.017), and lower blood pressure at admission (OR 0.980, p = 0.007) were independent risk factors for coinfection. Multidrug-resistant pathogens were detected in 30.8% of all coinfections. Patients with a viral infection are at high risk of bacterial coinfections, which carry a significant morbidity and mortality burden.

Water-miscible metalworking fluids (MWFs) are utilized in a variety of metal removal and forming operations. For end-use, formulation concentrates are diluted in water, creating conditions conducive to microbial growth and metabolism, possibly compromising the fluid's integrity and mechanically obstructing filters or piping systems. Metalworking machines offer additional habitats on surfaces that are in permanent or temporary contact with MWFs. For that reason, biocides have been incorporated into concentrates for years, but legal constraints will restrain their use in the future. While bacterial contamination of MWFs is well documented, fungal contamination is often overseen and infrequently reported in the literature. In this study, we report fungal prevalence in in-use MWFs sampled worldwide over 10 years, and we are convinced that the presence of fungi is the norm rather than the exception. In addition, we evaluated the inhibitory effect of fungicides on fungal growth, sporulation and spore viability using traditional culture-dependent methods and flow cytometry. In essence, we show that the effectiveness of these fungicides is limited and dependent on the chemical construction of the fluid. We think that the ecology created by water-diluted MWFs is of higher importance than the anti-fungal activity of single components.

Clonorchis sinensis is an important zoonotic parasite that is mainly prevalent in China, Korea, Vietnam and the Russian Far East. To explore the genetic variation and population structure of C. sinensis, an in silico analysis was conducted based on mitochondrial cytochrome c oxidase subunit 1 (COX1), ribosomal internal transcribed spacer 1 (ITS1) and ribosomal internal transcribed spacer 2 (ITS2) sequences. The sequences obtained from NCBI were truncated for further analyses, including haplotype network, phylogenetic, gene flow, diversity and neutrality analyses. The results showed that there were 20, 11 and 4 haplotypes for COX1, ITS1 and ITS2, respectively. The results of both the haplotype network and phylogenetic analyses indicated that the haplotypes for each type of sequence from the same country were not all clustered together. Haplotype diversity values were all lower than 0.5. Values of nucleotide diversity were higher than 0.005, except for ITS2. Tajima's D and Fu's Fs values were all negative, and p-values showed significant differences, indicating that the population of C. sinensis is growing. Fst values were all lower than 0.05. In conclusion, this study found that there are specific variations of C. sinensis in different countries, and the population of this parasite is growing with less genetic variation. The findings provide a crucial foundation for understanding the molecular epidemiology and population dynamics of C. sinensis.

Fast-growing mycobacteria cause difficult-to-treat infections due to their high intrinsic resistance to antibiotics as well as disinfectant agents. Mycobacterium abscessus complex (MAC) is the main cause of nontuberculous mycobacteria diseases. In this work, we evaluated the activity of the novel synthetic antimicrobial peptide, Agelaia-12, against Mycobacterium abscessus and M. massiliense. Agelaia-12 showed a minimum inhibitory concentration (MIC) of 25 μM detected against M. abscessus and M. massiliense with no cytotoxicity. The scanning electronic microscopy analysis of mycobacterial treated with Agelaia-12 demonstrated the presence of filamentous structures and aggregation of the cells. Congo red binding assay of M. abscessus exhibited altered dye accumulation after treatment with Agelaia-12. Treatment of M. abscessus- or M. massiliense-infected murine macrophages with Agelaia-12 decreased the mycobacterial load by 92% for the tested strains. Additionally, IFN-y KO mice infected with M. abscessus or M. massiliense and treated with Agelaia-12 showed a 98% reduction in lung bacterial load. Thus, the synthetic peptide Agelaia-12 may be a promising biomolecule for the treatment of mycobacteriosis, and its structural properties may serve as a foundational model for the design and development of novel pharmaceutical agents aimed at combating this disease.

Cysticercosis is a parasitic infection and neglected tropical disease caused by Taenia solium, or the pork tapeworm. Cysticercosis with central nervous system involvement, or neurocysticercosis, is a leading cause of chronic headaches and epilepsy in endemic regions, including Latin America and Asia. In the United States, the epidemiology of cysticercosis has not been well described. We conducted a cross-section serosurvey of Mexican-American adults residing along the Texas-Mexico border (Starr County, Texas) and identified an overall seroprevalence of 7.4% (45/605) for cysticercosis. Brain imaging studies conducted on seropositive study participants identified lesions consistent with calcified neurocysticercosis in 2 of the 45 seropositive individuals. Female sex (p = 0.021), employment in healthcare, caregiving, or social service (p = 0.002), and indoor occupation (p < 0.001) were found to be significantly associated with seropositivity. Further study is needed to evaluate the burden of neurocysticercosis and local transmission risk in this community.

Throughout Mycobacterium leprae's (M. leprae) evolutionary trajectory, nearly half of its genome was converted into pseudogenes. Despite this drastic reduction in genetic content, the genome sequence identity among M. leprae isolates worldwide is remarkably high compared to other pathogens. In this study, we investigated the genotype and morphotype of three M. leprae strains: the reference strain Thai-53 (genotype 1A), and two clinical isolates from Brazilian leprosy relapse patients, which were Br014-03 (genotypes 3I) and Br014-01(4N). We compared their genome sequences and their interaction with human Schwann cells from the ST88-14 lineage and with human primary macrophages. On the genetic level, we observed over a hundred missense mutations in the three strains, translated into significant phenotypic changes such as: prolonged doubling time, altered cytokine induction, reduced interaction rates, and decreased intracellular viability in Schwann cells. Our findings underscore the concept that despite their 99.992% identity, even small genomic disparities in M. leprae genomes can elicit substantial alterations in bacilli interaction with host cells and subsequent immune responses. Consequently, our data could lead to better comprehension of correlation between pathogen mutations and the diverse clinical manifestations observed in leprosy patients.

Antimicrobial resistance is recognized worldwide as one of the greatest threats to human and animal health and the environment. To evaluate the resistance rate of Gallibacterium anatis biovar haemolytica, which contributes to bacteremia, oophoritis, ovarian follicle degeneration, salpingitis, decreased egg production, and increased mortality in hens, strains isolated from the reproductive tracts of layers were analyzed. The oviducts were taken from three hens from each of 10 flocks manifesting clinical signs related to laying. Twenty-two isolates of G. anatis biovar haemolytica collected from the three parts of the reproductive system were identified using MALDI-TOF and molecular methods. The biovar's resistance to 19 antimicrobial substances was assessed using the disk diffusion (n = 8) and broth microdilution (n = 11) methods. The presence of virulence (gtxA, gyrB, and flfA) and antibiotic resistance (bla_ROB, aphA, tetB, and tetH) genes was examined using PCR. All the isolates were resistant to four or more classes of antibiotics and were considered multidrug-resistant. All such isolates were resistant to tilmicosin, tylosin, and enrofloxacin, 88.2% were to tetracycline, and 82.4% to vancomycin. The gtxA, gyrB, tetB, and tetH genes were demonstrated. Considering the present prevalence of multidrug resistance among G. anatis biovar haemolytica isolates from laying hen reproductive tracts, surveillance in reproductive flocks is warranted.

To gain insights into the prevalence and antimicrobial resistance patterns of major bacterial pathogens affecting largemouth bass (Micropterus salmoides) in the Pearl River Delta (PRD) region, Guangdong, China, a study was conducted from August 2021 to July 2022. During this period, bacteria were isolated and identified from the internal organs of diseased largemouth bass within the PRD region. The antimicrobial resistance patterns of 11 antibiotics approved for use in aquaculture in China were analyzed in 80 strains of Edwardsiella piscicida using the microbroth dilution method. The results showed that 151 bacterial isolates were obtained from 532 samples, with E. piscicida (17.29%, 92/532), Aeromonas veronii (4.70%, 25/532), and Nocardia seriolae (2.26%, 12/532) being the main pathogens. Notably, E. piscicida accounted for the highest proportion of all isolated bacteria, reaching 60.92% (92/151), and mainly occurred from November to April, accounting for 68.48% (63/92) of the cases. The symptoms in largemouth bass infected with E. piscicida included ascites, enteritis, and hemorrhaging of tissues and organs. The drug sensitivity results showed that the resistance rates of all E. piscicida strains to ciprofloxacin, all sulfonamides, thiamphenicol, florfenicol, enrofloxacin, doxycycline, flumequine, and neomycin were 96.25%, 60-63%, 56.25%, 43.75%, 40%, 32.5%, 16.25%, and 1.25%, respectively. In addition, 76.25% (61/80) of these strains demonstrated resistance to more than two types of antibiotics. Cluster analysis revealed 23 antibiotic types (A-W) among the 80 isolates, which were clustered into two groups. Therefore, tailored antibiotic treatment based on regional antimicrobial resistance patterns is essential for effective disease management. The findings indicate that in the event of an Edwardsiella infection in largemouth bass, neomycin, doxycycline, and flumequine are viable treatment options. Alternatively, one may choose drugs that are effective as determined by clinical drug sensitivity testing.

Lymphatic filariasis (LF) is a neglected tropical disease associated with poverty and poor environmental conditions. With the inclusion of vector control activities in LF surveillance actions, there is a need to develop simple methods to identify areas with higher mosquito density and thus a higher consequent risk of W. bancrofti transmission. An ecological study was conducted in Igarassu, which is in the metropolitan region of Recife, Pernambuco, Brazil. The mosquitoes were captured in 2060 houses distributed across 117 census tracts. The vector density index (VDI), which measures the average number of lymphatic-filariasis-transmitting mosquitoes per number of houses collected in the risk stratum, was constructed. Moreover, the social deprivation indicator (SDI) was constructed and calculated through principal component factor analysis. An average of 242 female C. quinquefasciatus were found in the high-risk stratum, while the average in the low-risk stratum was 108. The overall VDI was 6.8 mosquitoes per household. The VDI for the high-risk stratum was 13.2 mosquitoes per household, while for the low/medium-risk stratum, it was 5.2. This study offers an SDI for the density of C. quinquefasciatus mosquitoes, which can help reduce the costs associated with data collection and allows for identifying priority areas for vector control actions.