Streptococcus oralis an opportunistic bacterium has been reported to be involved in various blood borne infections like subacute bacterial endocarditis, septicemia, bacterial meningitis and in some cases dental caries too. Among various targets the peptide deformylase, of S.oralis appears to be most potent druggable target as it is involved in protein synthesis is opted for the current study. Due to unavailability of PDB structure of peptide deformylase from S. oralis the study initiates with homology modelling of the protein and 6OW2 of S pneumoniae is considered as the template. Thereafter, Molecular docking, Molecular dynamic simulation, ADME analysis, and MMPBSA analysis was carried out to explore the inhibitory potential of phyto-constituents as potential inhibitors for Peptide deformylase from S.oralis. Actinonin was considered as reference drug. Among 2370 phyto compounds the best observations were recorded for A1-Barrigenol (IMPHY010984) with binding affinity of -8.5 kcal/mol. Calculated RMSD, RMSF, Binding Free Energy for IMPHY010984 averaged at about 0.10 ± 0.03 nm, 0.08 ± 0.05 nm, 131 ± 21 kJ/mol respectively whereas the RMSD, RMSF, Binding Free Energy recorded for reference drug averaged at about 0.19 ± 0.04 nm, 0.11 ± 0.08 nm, -94 ± 18 kJ/mol respectively. Based on in silico observations IMPHY010984 is proved out as superior candidate over reference drug. The study reflects the potential of IMPHY010984 as prophylactic therapeutics for S.oralis.

Opportunistic pathogens are environmental microbes that are generally harmless and only occasionally cause disease. Unlike obligate pathogens, the growth and survival of opportunistic pathogens does not rely on host infection or transmission. Their versatile lifestyles make it challenging to decipher how and why virulence has evolved in opportunistic pathogens. The Coincidental Evolution Hypothesis (CEH) postulates that virulence results from exaptation or pleiotropy, i.e., traits evolved for adaptation to living in one environment that have a different function in another. In particular, adaptation to avoid or survive protist predation has been suggested to contribute to the evolution of bacterial virulence (the training grounds hypothesis). Here we used experimental evolution to determine how the selective pressure imposed by a protist predator impacts the virulence and fitness of a ubiquitous environmental opportunistic bacterial pathogen that has acquired multi-drug resistance: Serratia marcescens. To this aim, we evolved S. marcescens in the presence or absence of generalist protist predator, Tetrahymena thermophila. After 60 days of evolution, we evaluated genotypic and phenotypic changes by comparing evolved S. marcescens to the ancestral strain. Whole genome shotgun (WGS) sequencing of the entire evolved populations and individual isolates revealed numerous cases of parallel evolution, many more than statistically expected by chance, in genes associated with virulence. Our phenotypic assays suggested that evolution in the presence of a predator maintained virulence, whereas evolution in the absence of a predator resulted in attenuated virulence. We also found a significant correlation between virulence, biofilm formation, growth, and grazing resistance. Overall, our results provide evidence that bacterial virulence and virulence related traits are maintained by selective pressures imposed by protist predation.

Pneumocystis jirovecii pneumonia (PCP) is a life-threatening condition found in immunocompromised individuals, especially in human immunodeficiency virus (HIV) positive patients. Here, we report a case of PCP in a presumably immunocompetent 25-year-old male patient who presented with a one-month history of chest pain, dyspnea, and a nonproductive cough with recent development of night sweats. The patient recently immigrated to the United States without any known medical or family history. A chest radiograph revealed moderate pneumothorax for which a chest tube was placed. A chest computed tomography (CT) scan revealed diffuse lung disease with multiple thin- and thick-walled cystic lesions on a background of diffuse ground-glass opacities. Based on these radiologic findings and subsequent positive HIV serology, there was a high suspicion of PCP. Bronchoalveolar lavage was performed, and PCR for Pneumocystis jirovecii was positive. Appropriate treatment was initiated, and the patient recovered well. Through this report, we aim to highlight the importance of recognizing the various clinical and radiologic findings of PCP even in patients with no overt risk factors. Prompt and targeted treatment could mitigate morbidity and mortality associated with this opportunistic pathogen.

BACKGROUND: Achromobacter spp. are opportunistic pathogens, mostly infecting immunocompromised patients and patients with cystic fibrosis (CF) and considered as difficult-to-treat pathogens due to both intrinsic resistance and the possibility of acquired antimicrobial resistance. Species identification remains challenging leading to imprecise descriptions of resistance in each taxon. Cefiderocol is a broad-spectrum siderophore cephalosporin increasingly used in the management of Achromobacter infections for which susceptibility data remain scarce. We aimed to describe the susceptibility to cefiderocol of a collection of Achromobacter strains encompassing different species and isolation sources from CF or non-CF (NCF) patients.
METHODS: We studied 230 Achromobacter strains (67 from CF, 163 from NCF patients) identified by nrdA gene-based analysis, with available susceptibility data for piperacillin-tazobactam, meropenem and trimethoprim-sulfamethoxazole. Minimal inhibitory concentrations (MICs) of cefiderocol were determined using the broth microdilution reference method according to EUCAST guidelines.
RESULTS: Strains belonged to 15 species. A. xylosoxidans represented the main species (71.3%). MICs ranged from ≤ 0.015 to 16 mg/L with MIC50/90 of ≤ 0.015/0.5 mg/L overall and 0.125/2 mg/L against 27 (11.7%) meropenem-non-susceptible strains. Cefiderocol MICs were not related to CF/NCF origin or species although A. xylosoxidans MICs were statistically lower than those of other species considered as a whole. Considering the EUCAST non-species related breakpoint (2 mg/L), 228 strains (99.1%) were susceptible to cefiderocol. The two cefiderocol-resistant strains (A. xylosoxidans from CF patients) represented 3.7% of meropenem-non-susceptible strains and 12.5% of MDR strains.
CONCLUSIONS: Cefiderocol exhibited excellent in vitro activity against a large collection of accurately identified Achromobacter strains, irrespective of species and origin.

Gynecological and obstetric infectious diseases are crucial to women\'s health. There is growing evidence that links the presence of Fusobacterium nucleatum (F. nucleatum), an anaerobic oral commensal and potential periodontal pathogen, to the development and progression of various human diseases, including cancers. While the role of this opportunistic oral pathogen has been extensively studied in colorectal cancer in recent years, research on its epidemiological evidence and mechanistic link to gynecological diseases (GDs) is still ongoing. Thus, the present review, which is the first of its kind, aims to undertake a comprehensive and critical reappraisal of F. nucleatum, including the genetics and mechanistic role in promoting adverse pregnancy outcomes (APOs) and various GDs, including cancers. Additionally, this review discusses new conceptual advances that link the immunomodulatory role of F. nucleatum to the development and progression of breast, ovarian, endometrial, and cervical carcinomas through the activation of various direct and indirect signaling pathways. However, further studies are needed to explore and elucidate the highly dynamic process of host-F. nucleatum interactions and discover new pathways, which will pave the way for the development of better preventive and therapeutic strategies against this pathobiont.

Understanding the dynamic change in abundance of both fecal and opportunistic waterborne pathogens in urban surface water under different abiotic and biotic factors helps the prediction of microbiological water quality and protection of public health during recreational activities, such as swimming. However, a comprehensive understanding of the interaction among various factors on pathogen behavior in surface water is missing. In this study, the effect of salinity, light, and temperature and the presence of indigenous microbiota, on the decay/persistence of Escherichia coli and Pseudomonas aeruginosa in Rhine River water were tested during 7 days of incubation with varying salinity (0.4, 5.4, 9.4, and 15.4 ppt), with light under a light/dark regime (light/dark) and without light (dark), temperature (3, 12, and 20 °C), and presence/absence of indigenous microbiota. The results demonstrated that light, indigenous microbiota, and temperature significantly impacted the decay of E. coli. Moreover, a significant (p<0.01) four-factor interactive impact of these four environmental conditions on E. coli decay was observed. However, for P. aeruginosa, temperature and indigenous microbiota were two determinate factors on the decay or growth. A significant three-factor interactive impact between indigenous microbiota, temperature, and salinity (p<0.01); indigenous microbiota, light, and temperature (p<0.01); and light, temperature, and salinity (p<0.05) on the decay of P. aeruginosa was found. Due to these interactive effects, caution should be taken when predicting decay/persistence of E. coli and P. aeruginosa in surface water based on a single environmental condition. In addition, the different response of E. coli and P. aeruginosa to the environmental conditions highlights that E. coli monitoring alone underestimates health risks of surface water by non-fecal opportunistic pathogens, such as P. aeruginosa. KEY POINTS: Abiotic and biotic factors interactively affect decay of E. coli and P. aeruginosa E.coli and P.aeruginosa behave significantly different under the given conditions Only E. coli as an indicator underestimates the microbiological water quality.

The increasing global prevalence of antimicrobial resistance in Acinetobacter baumannii has led to concerns regarding the effectiveness of infection treatment. Moreover, the critical role of virulence factor genes in A. baumannii\'s pathogenesis and its propensity to cause severe disease is of particular importance. Comparative genomics, including multi-locus sequence typing (MLST), enhances our understanding of A. baumannii epidemiology. While there is substantial documentation on A. baumannii, a comprehensive study of the antibiotic-resistant mechanisms and the virulence factors contributing to pathogenesis, and their correlation with Sequence Types (STs) remains incompletely elucidated. In this study, we aim to explore the relationship between antimicrobial resistance genes, virulence factor genes, and STs using genomic data from 223 publicly available A. baumannii strains. The core phylogeny analysis revealed five predominant STs in A. baumannii genomes, linked to their geographical sources of isolation. Furthermore, the resistome and virulome of A. baumannii followed an evolutionary pattern consistent with their pan-genome evolution. Among the major STs, we observed significant variations in resistant genes against \"aminoglycoside\" and \"sulphonamide\" antibiotics, highlighting the role of genotypic variations in determining resistance profiles. Furthermore, the presence of virulence factor genes, particularly exotoxin and nutritional / metabolic factor genes, played a crucial role in distinguishing the major STs, suggesting a potential link between genetic makeup and pathogenicity. Understanding these associations can provide valuable insights into A. baumannii\'s virulence potential and clinical outcomes, enabling the development of effective strategies to combat infections caused by this opportunistic pathogen.

Achromobacter spp. are opportunistic pathogens of environmental origin increasingly isolated in patients with underlying conditions like cystic fibrosis (CF). Despite recent advances, their virulence factors remain incompletely studied, and siderophore production has not yet been investigated in this genus. The aim of this study was to evaluate the production of siderophores in a large collection of Achromobacter spp. and evaluate the variability according to the origin of the strain and species. A total of 163 strains were studied, including 128 clinical strains (CF and non-CF patients) and 35 strains of environmental origin. Siderophores were quantified by the liquid chrome azurol-sulphonate assay. Species were identified by nrdA gene-based phylogeny. Strains were assigned to 20 species, with Achromobacter xylosoxidans being the most represented (51.5% of strains). Siderophore production was observed in 72.4% of the strains, with amounts ranging from 10.1% to 90% siderophore units. A significantly higher prevalence of siderophore-producing strains and greater production of siderophores were observed for clinical strains compared with strains of environmental origin. Highly variable observations were made according to species: A. xylosoxidans presented unique characteristics (one of the highest prevalence of producing strains and highest amounts produced, particularly by CF strains). Siderophores are important factors for bacterial growth commonly produced by members of the Achromobacter genus. The significance of the observations made during this study must be further investigated. Indeed, the differences observed according to species and the origin of strains suggest that siderophores may represent important determinants of the pathophysiology of Achromobacter spp. infections and also contribute to the particular epidemiological success of A. xylosoxidans in human infections.
OBJECTIVE: Achromobacter spp. are recognized as emerging opportunistic pathogens in humans with various underlying diseases, including cystic fibrosis (CF). Although their pathophysiological traits are increasingly studied, their virulence factors remain incompletely described. Particularly, siderophores that represent important factors of bacterial growth have not yet been studied in this genus. A population-based study was performed to explore the ability of members of the Achromobacter genus to produce siderophores, both overall and in relevant subgroups (Achromobacter species; strain origin, either clinical-from CF or non-CF patients-or environmental). This study provides original data showing that siderophore production is a common trait of Achromobacter strains, particularly observed among clinical strains. The major species, Achromobacter xylosoxidans, encompassed both one of the highest prevalence of siderophore-producing strains and strains producing the largest amounts of siderophores, particularly observed for CF strains. These observations may represent additional advantages accounting for the epidemiological success of this species.

Cryptococcosis, a relatively uncommon infection in cancer patients is often associated with delayed diagnosis and high fatality rate due to its highly heterogeneous and protean manifestations. Early recognition and initiation of appropriate antifungal therapy might have a favourable outcome in such cases. Here we report three cases of Cryptococcosis among cancer patients in a tertiary care cancer centre in South India. All three patients were males of different ages at presentation with immunosuppression in the form of solid organ or hematologic malignancy and were using immunosuppressive medications like steroids or chemotherapeutic agents. They presented with cryptococcemia and cryptococcal meningitis. Patients with microbiologically proven cryptococcosis had poor outcome in this subgroup of patients.

Mortality of chicken embryos and first-week chickens was reported in a commercial incubator company in Costa Rica. Six 1-day-old Cobb chickens and twenty-four embryonated chicken eggs were examined in the Laboratory of Avian Pathology and the Laboratory of Bacteriology of the National University of Costa Rica. Twelve dead-in-shell embryos showed maceration and were immersed in a putrid, turbid, slightly thick brown liquid. Additionally, the other 12 embryonated eggs had milky yellow-orange content. The livers of those embryos had congestion, haemorrhages and multifocal cream foci of necrosis. Granulocytic infiltration was observed in the bursa of Fabricius, myocardium, liver, lung and kidney. Livers and egg yolks from six embryonated chickens and all 1-day-old chickens were aseptically collected and cultured. In addition, tissues from six better conserved embryos and all 1-day-old chickens were fixed in buffered formalin and embedded in paraffin. Biochemical and molecular tests identified Comamonas testosteroni as the cause of the early, middle and late embryo mortality. As all the eggshells from the sampled embryonated eggs were dirty with soiled a fecal matter, contamination after manipulating the eggs was considered the source of infection. C. testosteroni is an environmental microorganism that has rarely been reported to cause human disease. To our knowledge, this is the first report of C. testosteroni causing mortality in a hatchery. Cleaning and disinfection using ozone were implemented in the hatchery to eliminate the embryo mortality associated with C. testosteroni.