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Here, we report the draft genome sequence of Salinicoccus roseus H15, isolated from desert rock varnish in Ma'an, Jordan. The genome size is 2,457,773 bp with a GC content of 49.31 mol%. The genome includes 3,064 genes and 135 carbohydrate-active enzymes, demonstrating adaptations for survival in extreme environments.

Desert environments harbor unique microbial communities. This study focuses on Cellulosimicrobium funkei isolate RVMD1, isolated from rock varnish in the Ma'an Desert. Initial identification was achieved using 16S rRNA gene sequencing, followed by whole-genome sequencing (WGS) for comprehensive characterization. The genome comprises 4,264,015 base pairs (857 contigs) with a high G + C content of 74.59%. A total of 4,449 proteins were predicted. Comparative analysis utilizing OrthoANI, ANI, AAI, and dDDH metrics suggests that RVMD1 belongs to the C. cellulans group, with the highest similarity to C. funkei (97.71% ANI). Phylogenomic analysis of 43 Cellulosimicrobium genomes revealed significant heterogeneity within the genus. Our results challenge current systematics, with C. cellulans potentially representing up to 9 distinct genomospecies. Isolate RVMD1 shows genetic adaptations to its desert environment, including genes for denitrification, oxygen and sulfur cycling, and diverse hydrogen metabolism. Pangenomic analysis uncovered a considerable number of unique genes within RVMD1, highlighting its genetic distinctiveness. Gene family expansions suggest evolution in response to stressors like UV radiation and nutrient limitation. This study represents the first whole-genome analysis of a bacterium isolated from Jordanian rock varnish, emphasizing the value of WGS in understanding microbial diversity and adaptation in extreme environments., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Alnaimat, Abushattal and Dmour.)

Background and Objectives: Healthcare workers in hospitals are exposed to infectious diseases that occur in the hospital making them a source of infection for the patients. It is interfaced as cross-contamination agents for MRSA and MR-CoNS, and preventive measures need to be adapted accordingly. The study aimed to assess Methicillin-Resistant Staphylococcus (MRS) on the skin and nasal cavities of healthcare workers (HCWs) and identifying isolates to the species level., Materials and Methods: Swab samples were cultured on mannitol salt agar (MSA) to obtain MRS and determine their ability to produce coagulase. Their susceptibility to antibiotics were determined by agar screening and disk diffusion methods and further identification was done at the species level., Results: The highest percentage of methicillin resistant coagulase positive Staphylococci (MRCoPS) was reported among skins of male HCWs, (71.4%) were identified as MRSA. The highest levels of methicillin resistant coagulase negative Staphylococci (MRCoNS) were mainly detected in both nasal cavities, (75%) were identified as MRSE. MRSA was reported from doctors (p-value 0.033), whereas the highest incidence of MRSE was obtained from the nurses (p-value 0.048)., Conclusion: This study highlighted that incidence of MRSA was mainly detected in doctors and MRCoNS in both nasal cavities. The highest percentage of MRCoNS was recovered from the patients' room followed by the reception table. Moreover, vancomycin is suggested to be highly effective in managing and controlling S. aureus , MRSA- and MRSE related infections., (Copyright© 2024 The Authors. Published by Tehran University of Medical Sciences.)

Background: Globally, resistance to antimicrobial drugs is a major hazard to public health. Infections that were once easily treatable with antibiotics are becoming harder to control, leading to prolonged illnesses, increased mortality rates, and higher healthcare costs., Aim: This study intended to assess the antimicrobial, specifically the anti-Methicillin resistant Staphylococcus aureus (MRSA), and anticancer properties of different extracts obtained from A. herba-alba (AHA)., Methods: The antibacterial tests of AHA were performed on two Gram-negative bacterial strains ( Escherichia coli and Klebsiella pneumonia ), two Gram-positive bacterial strains (Methicillin-resistant Staphylococcus aureus (MRSA), and Staphylococcus aureus). Initial screening for antibacterial activities was conducted using the well diffusion technique. Subsequently, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined through the broth-dilution assay. The anticancer test was carried out in vitro on a human colorectal carcinoma cell line (HCT-116) using MTT assay., Results: Among all extracts, n -hexane extract of AHA was the most effective against S. aureus with the highest inhibition zone (24.67 mm ± 0.58) compared to standard antibiotic (erythromycin, 24.00 mm) followed by the methanolic extract against MRSA (24.00 mm ± 1.73). The methanol extract of AHA showed the highest antibacterial activity against MRSA. The results of MIC and MBC of the AHA methanol extract against MRSA were 1.17 ± 1.09 and 9.375 ± 0.0 mg/ml, respectively, demonstrating therapeutically significant antibacterial activity. Ethyl acetate extract has no antibacterial activity against E. coli and K. pneumonia . The findings indicated that the methanol extract of AHA exhibited the highest efficacy against the colorectal carcinoma cell line (HCT-116), with an IC 50 value of 126.61 ± 13.35 μg/ml., Conclusion: These findings suggest that the methanol extract of AHA could be considered as a potential agent to serve as a source of antibacterial and anticancer compounds., Competing Interests: The authors declare that there is no conflict of interest.

The marine bacterium Photobacterium damselae subsp. piscicida ( Pdp ) causes photobacteriosis in fish and important financial losses in aquaculture, but knowledge of its virulence factors is still scarce. We here demonstrate that an unstable plasmid (pPHDPT3) that encodes a type III secretion system (T3SS) is highly prevalent in Pdp strains from different geographical origins and fish host species. We found that pPHDPT3 undergoes curing upon in vitro cultivation, and this instability constitutes a generalized feature of pPHDPT3-like plasmids in Pdp strains. pPHDPT3 markers were detected in tissues of naturally-infected moribund fish and in the Pdp colonies grown directly from the fish tissues but were undetectable in a fraction of the colonies produced upon the first passage of the primeval colonies on agar plates. Notably, cured strains exhibited a marked reduction in virulence for fish, demonstrating that pPHDPT3 is a major virulence factor of Pdp . The attempts to stabilize pPHDPT3 by insertion of antibiotic resistance markers by allelic exchange caused an even greater reduction in virulence. We hypothesize that the existence of a high pressure to shed pPHDPT3 plasmid in vitro caused the selection of clones with off-target mutations and gene rearrangements during the process of genetic modification. Collectively, these results show that pPHDPT3 constitutes a novel, hitherto unreported virulence factor of Pdp that shows a high instability in vitro and warn that the picture of Pdp virulence genes has been historically underestimated, since the loss of the T3SS and other plasmid-borne genes may have occurred systematically in laboratories for decades.

The ability to metabolize sucrose is a variable trait within the family Vibrionaceae. The marine bacterium Photobacterium damselae subsp. damselae (Pdd), pathogenic for marine animals and humans, is generally described as negative for sucrose utilization (Scr - ). Previous studies have reported sucrose-utilizing isolates (Scr + ), but the genetic basis of this variable phenotype remains uncharacterized. Here, we carried out the genome sequencing of five Scr + and two Scr - Pdd isolates and conducted a comparative genomics analysis with sixteen additional Pdd genomes sequenced in previous studies. We identified two different versions of a four-gene cluster (scr cluster) exclusive of Scr + isolates encoding a PTS system sucrose-specific IIBC component (scrA), a fructokinase (scrK), a sucrose-6-phosphate hydrolase (scrB), and a sucrose operon repressor (scrR). A scrA deletion mutant did not ferment sucrose and was impaired for growth with sucrose as carbon source. Comparative genomics analyses suggested that scr clusters were acquired by horizontal transfer by different lineages of Pdd and were inserted into a recombination hot-spot in the Pdd genome. The incongruence of phylogenies based on housekeeping genes and on scr genes revealed that phylogenetically diverse gene clusters for sucrose utilization have undergone extensive horizontal transfer among species of Vibrio and Photobacterium., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

The marine bacterium Photobacterium damselae subsp. damselae is a pathogen that causes disease in diverse marine animals, and is also a serious opportunistic human pathogen that can cause fatal infections. Strains of this pathogen isolated from diseased European sea bass in aquaculture facilities in the Turkish coast of the Black Sea were found to exhibit reduced sensitivity to multiple antimicrobials. Selected representative strains were subjected to complete genome sequencing and plasmid characterization. It was found that multidrug resistant (MDR) isolates harboured large conjugative plasmids sharing part of their sequence backbone with pAQU-group plasmids, hitherto reported exclusively in China and Japan. Four new pAQU-group versions of plasmids were identified in the present study, containing distinct combinations of the resistance determinants tetB, floR, sul2, qnrVC, dfrA and strAB. Conjugative transfer of pPHDD2-OG2, a representative plasmid of 170,998 bp, occurred at high frequencies (2.2 × 10 -2 transconjugants per donor cell), to E. coli and to pathogenic P. damselae subsp. damselae and subsp. piscicida strains. Upon transfer, pPHDD2-OG2 conferred reduced susceptibility to a number of antimicrobials to the recipient strains. Comparative genomics analysis of host strains suggested that these MDR plasmids of the pAQU-group were acquired by different genetic lineages of Pdd. This study provides evidence that P. damselae subsp. damselae isolated from diseased fish constitute a reservoir for conjugative MDR pAQU-group plasmids in the Mediterranean basin, and have the potential to spread to diverse bacterial species.

Here, we report the draft genome sequences of two strains of the fish pathogen Photobacterium damselae subsp. piscicida , isolated from Salmo salar (SNW-8.1) and Seriola quinqueradiata (PP3). The identification of a type III secretion system in the two genomes furthers our understanding of the pathobiology of this subspecies., (Copyright © 2019 Abushattal et al.)