Psychrobacter arenosus bacteremia after blood transfusion, France

Antimicrobial Resistant Pathogens in the Oral Cavity of White (Carcharodon carcharias), Bull (Carcharhinus leucas) and Tiger (Galeocerdo cuvier) Sharks from the East Coast of Australia

Australia has one of the highest incidences of shark bites worldwide. Previous research on sharks has detected antibiotic-resistant pathogenic bacteria in the oral cavity, however, no such research has been conducted on species found in Australasian waters. In this study, 197 bacterial isolates were obtained from oral swabs taken from 153 sharks, including white (Carcharodon carcharias), tiger (Galeocerdo cuvier) and bull sharks (Carcharhinus leucas) caught on the east coast of Australia between May 2018 and April 2022. Isolates were identified using MALDI-TOF, and a disc diffusion assay was used to determine the antibiotic sensitivity of 72 isolates considered potential pathogens, including members of the genera Pseudomonas, Vibrio, Aeromonas, Enterobacter, Klebsiella and Psychrobacter. Resistance to one or more antibiotics was common, with 60%, 73%, and 74% of isolates from white, tiger and bull sharks resistant to one or more antibiotics, respectively. This research provides insights into which antibiotics are most suitable for treating shark bite wounds in eastern Australia, and possibly more broadly, to prevent infection. This study identified that over 51% of pathogens in the oral cavity of Australian sharks are resistant to one or more antibiotics, with most pathogens being resistant to commonly prescribed antibiotics. This research provides important information for medical professionals when it comes to treaty wounds inflicted by shark bites.

Abnormal gill color of Manila clam Ruditapes philippinarum due to the unhealthy gut mcirobiota and the role of gut-gill axis

The Manila clam (Ruditapes philippinarum) is an ecologically and economically important species. Recently, a novel disease of Manila clam with abnormal gill colour has emerged, leading to growth inhibition and death in severe cases. In this study, a multi-omics approach was used to investigate the underlying mechanisms of abnormal gill colour in Manila clam and its association with gut microbiota. High-throughput sequencing revealed a reduction in the uniformity of gut microbiota in diseased clams, with increased abundance of Pseudomonas and Pseudoaltermonas. Network and null model analyses revealed a decline in microbiota stability and a shift toward deterministic assembly in diseased clams. Transcriptomic analysis revealed different gene expression profiles in the gills of healthy and diseased Manila clams, including down-regulation of several immune-related genes such as genes encoding heat shock proteins and involved in Toll and Imd signalling pathways. A total of 38 specialists were identified in the gut microbiota of diseased Manila clams based on their specificity and occupancy. Four of them (two Psychrobacter, one Pseudoaltermonas and one Halomonas) were closely correlated with the expression of gill genes associated with abnormal gill colour. In addition, a gene encoding a major vault protein was identified as the keystone of abnormal gill colour through the network of host genes and their gut microbiota. This study revealed the substantial variation in gut microbiota and gill gene expression in Manila clam with abnormal gill colour and provided insights into the complex host-microbiota interactions involved in disease development.

Transfusion-transmitted bacterial infection risk due to the proliferation of psychrotrophic bacterial species in RBCs and their difficulty in detection

BACKGROUND

Reports of cases of bacterial infection due to transfusion of red blood cell (RBC) components (RBC-TTBI) are relatively rare. Hence, the possibility of undetectable bacterial contamination in RBCs, especially by psychrotrophic bacteria, must be clarified.

STUDY DESIGN AND METHODS

We assessed nine psychrotrophic bacterial species, including those implicated in bacteremia or RBC-TTBIs. They were cultured on plates from 4 to 37°C to determine their optimal growth temperatures. We also assessed the detection capabilities of the automated culture/alarm system BACT/ALERT VIRTUO (VIRTUO) using BPA (aerobic) and BPN (anaerobic) bottles. In addition, bacteria-inoculated RBCs were incubated at 4°C for 42 days, with samples assessed weekly for bacterial growth using plate culture, VIRTUO, visual inspection, and endotoxin production.

RESULTS

Two Psychrobacter species exhibited weak or no proliferation at temperatures ≥30°C in plate cultures. Three Pseudomonas species, one Psychrobacter species, and one psychrotrophic lactic acid bacteria proliferated in RBCs at 4°C, reaching 104-108 colony-forming units/mL (growth count) and 15-39,230 pg/mL (endotoxin production) by day 14. VIRTUO, operating at 36°C, failed to consistently yield reliable results for any of the tested bacterial species. Notably, visual changes in bag appearance were observed from day 21 in four species that proliferated in RBCs.

DISCUSSION

Each psychrotrophic bacteria demonstrated a specific temperature preference for optimal proliferation. Standard culture tests, typically conducted at 35-37°C, often fail to detect the growth of such bacteria, suggesting they may be overlooked in the cultural analysis of suspected RBC-TTBI cases.

Psychrobacter Infections in Humans-A Narrative Review of Reported Cases

BACKGROUND

Psychrobacter species are aerobic, Gram-negative, spherical-to-rod-shaped, psychrophilic bacteria that belong to the Moraxellaceae family. In spite of their uncommon manifestation in the general population, infections due to Psychrobacter spp. are increasingly identified especially in immunocompromised individuals or patients with severe comorbidities.

OBJECTIVES

This review aims to analyze all reported instances of Psychrobacter spp. infections in humans, with an emphasis on data pertaining to epidemiology, microbiology, antimicrobial resistance, treatment strategies, and mortality outcomes.

METHODS

A narrative review was performed through a literature search of PubMed/MedLine and Scopus databases.

RESULTS

In total, 12 articles offered data on 12 patients infected with Psychrobacter spp. Their mean age was 33.41 years, while 63.64% of them were male. Immunosuppression was the predominant risk factor (33.3%). Bacteremia was the most commonly observed type of infection (41.6%), followed by meningitis, skin infection, and conjunctivitis. Psychrobacter immobilis was the most usually identified species (33.3%). The pathogen exhibited sensitivity to most antimicrobials. The most widely administered antimicrobials included cephalosporins (70%), followed by aminopenicillins and vancomycin (40%, respectively). The clinical outcome depended primarily on the infection site; mortality rate was high (44.4%), especially in cases of bacteremia (50%).

CONCLUSION

Due to the potential of Psychrobacter spp. to cause serious infection, clinicians and laboratory professionals should consider it in the differential diagnosis in patients with infections by Gram-negative spherical bacteria, particularly in patients with significant comorbidities and immunodeficiency, in order to accurately establish the diagnosis and proceed to the right treatment.

Psychrobacter raelei sp. nov., isolated from a dog with peritonitis

A strain belonging to the genus Psychrobacter, named PraFG1T, was isolated from the peritoneal effusion of a stray dog during necropsy procedures. The strain was characterized by the phylogenetic analyses based on the nucleotide sequences of 16S and 23S rRNA genes and of gyrB, which placed the strain in the genus Psychrobacter. The nucleotide sequence of the chromosome confirmed the placement, showing an average nucleotide identity of 72.1, 77.7, and 77.5 % with the closest related species, namely Psychrobacter sanguinis, Psychrobacter piechaudii, and Psychrobacter phenylpyruvicus, respectively, thus indicating a novel species. The polyphasic characterization by biochemical and fatty acid profiling as well as MALDI-TOF supported those findings. The strain was halotolerant, capable of growing within a temperature range between 4 and 37 °C, it was positive for catalase and oxidase, indole producing, nitrate reducing, and not able to use 5-keto-d-gluconic acid as a carbon source. Taken together, the data suggest that strain PraFG1T could be considered as representing a novel species, with the name Psychrobacter raelei sp. nov. (type strain PraFG1T=CIP 111873T=LMG 32233T).

Bacterial Infections in Sea Turtles

Sea turtles are important for the maintenance of marine and beach ecosystems, but they are seriously endangered due to factors mainly related to human activities and climate change such as pollution, temperature increase, and predation. Infectious and parasitic diseases may contribute to reducing the number of sea turtles. Bacteria are widespread in marine environments and, depending on the species, may act as primary or opportunistic pathogens. Most of them are able to infect other animal species, including humans, in which they can cause mild or severe diseases. Therefore, direct or indirect contact of humans with sea turtles, their products, and environment where they live represent a One Health threat. Chlamydiae, Mycobacteria, and Salmonellae are known zoonotic agents able to cause mild or severe diseases in sea turtles, other animals, and humans. However, other bacteria that are potentially zoonotic, including those that are antimicrobially resistant, are involved in different pathologies of marine turtles.

Microbial composition of carapace, feces, and water column in captive juvenile green sea turtles with carapacial ulcers

Introduction

Green sea turtles are endangered marine reptiles. Carapacial ulcers will develop on juvenile green sea turtles during artificial rescue, seriously affecting their health and potentially leading to death.

Methods

To determine the pathogens causing ulcerative carapacial disease, we performed 16S and ITS high-throughput sequencing, and microbial diversity analysis on samples from carapacial ulcers, healthy carapaces, feces, and seawater of juvenile green sea turtles.

Results

Our analysis showed that changes in microbial diversity of green sea turtle feces and seawater were not significantly associated with ulcerative carapacial disease.

Discussion

Psychrobacter sp. is the dominant species in the carapacial ulcers of green sea turtles. The bacterium is present in both healthy turtles and seawater where carapacial ulcers did not occur and decreasing seawater temperatures are likely responsible for the infection of juvenile green turtles with Psychrobacter sp. This is the first study on carapacial ulcers in captive juvenile green sea turtles. Our research provides theoretical guidance for the prevention and control of carapacial ulcers in captive juvenile green sea turtles.

Psychrobacter piechaudii shunt infection: first report of human infection

Psychrobacter piechaudii is a recently described species of Gram-negative bacteria in the Moraxellaceae family. No cases of human infection due to this species have been described before. We report the case of an ex-premature infant girl with hydrocephalus secondary to intraventricular haemorrhage who underwent multiple cerebrospinal fluid (CSF) shunt operations. She ultimately developed Psychrobacter piechaudii meningitis, presenting as ventriculoperitoneal shunt dysfunction and wound leak, which necessitated removal of the shunt, a period of external ventricular drainage and antibiotics. We found this organism to be sensitive to intravenous ceftazidime (50 mg/kg) and ciprofloxacin, and a 7-10 day treatment course prior to shunt re-insertion (and 3 week total course) was sufficient. The patient is well post-operatively. To the best of our knowledge, this is the first reported case of Psychrobacter piechaudii infection in a human.

Characterization of two enzymes from Psychrobacter cryohalolentis that are required for the biosynthesis of an unusual diacetamido-d-sugar

Psychrobacter cryohalolentis strain K5^T is a Gram-negative organism first isolated in 2006. It has a complex O-antigen that contains, in addition to l-rhamnose and d-galactose, two diacetamido- and a triacetamido-sugar. The biochemical pathways for the production of these unusual sugars are presently unknown. Utilizing the published genome sequence of the organism, we hypothesized that the genes 0612, 0638, and 0637 encode for a 4,6-dehydratase, an aminotransferase, and an N-acetyltransferase, respectively, which would be required for the biosynthesis of one of the diacetamido-sugars, 2,4-diacetamido-2,4,6-trideoxy-d-glucose, starting from UDP-N-acetylglucosamine. Here we present functional and structural data on the proteins encoded by the 0638 and 0637 genes. The kinetic properties of these enzymes were investigated by a discontinuous HPLC assay. An X-ray crystallographic structure of 0638, determined in its external aldimine form to 1.3 Å resolution, demonstrated the manner in which the UDP ligand is positioned into the active site. It is strikingly different from that previously observed for PglE from Campylobacter jejuni, which functions on the same substrate. Four X-ray crystallographic structures were also determined for 0637 in various complexed states at resolutions between 1.3 and 1.55 Å. Remarkably, a tetrahedral intermediate mimicking the presumed transition state was trapped in one of the complexes. The data presented herein confirm the hypothesized functions of these enzymes and provide new insight into an unusual sugar biosynthetic pathway in Gram-negative bacteria. We also describe an efficient method for acetyl-CoA synthesis that allowed us to overcome its prohibitive cost for this analysis.

Investigating the culturable atmospheric fungal and bacterial microbiome in West Texas: implication of dust storms and origins of the air parcels

Individuals often experience ailments such as allergies, asthma and respiratory tract infections throughout the year. Weather reports often include estimations of common allergens that can affect these individuals. To describe the local 'atmospheric microbiome' in Lubbock, Texas, USA, we examined the culturable fungal and bacterial microbiome present in the air on calm and dust storm days using internal transcribed spacer (ITS)-1 and 16S rRNA amplicon sequencing, respectively. While some types of airborne fungi were frequently present throughout the year, distinct differences were also observed between calm and dust storm days. We also observed the influence of the origin of air parcels and wind elevation of the air trajectory. The most abundant genera of fungi identified during the study period were Cryptococcus, Aureobasidium, Alternaria, Cladosporium and Filobasidium. This observation was not surprising considering the agricultural intensive environment of West Texas. Interestingly, Cladosporium, a common allergenic mold, was increased during days with dust storm events. The predominant bacterial genera observed were Bacillus, Pseudomonas, Psychrobacter, Massilia and Exiguobacterium. The relative abundance of the psychrophiles, Psychrobacter and Exiguobacterium, was surprising, given the semi-aridity of West Texas. Coupling our observations with back trajectories of the wind (Hybrid Single-Particle Lagrangian Integrated Trajectory models) demonstrated that dust storms, regional anthropogenic activity and origin of air parcels are important influences on the diversity and temporal presence of the atmospheric microbiome.

Draft Genome Sequence of Psychrobacter okhotskensis Strain 5179-1A, Isolated from a Raw Cured Ham Storage Crate

We present the draft genome sequence of Psychrobacter okhotskensis strain 5179-1A, which was isolated from a raw cured ham storage crate. Its size and GC content are 3.4 Mb and 43.4%, respectively. The 16S rRNA sequences of strain 5179-1A and P. okhotskensis MD17^T are 100% identical.

We present the draft genome sequence of Psychrobacter okhotskensis strain 5179-1A, which was isolated from a raw cured ham storage crate. Its size and GC content are 3.4 Mb and 43.4%, respectively. The 16S rRNA sequences of strain 5179-1A and P. okhotskensis MD17^T are 100% identical.

Different growth kinetics in blood components and genetic analysis of Lactococcus garvieae isolated from platelet concentrates

BACKGROUND

In 2014, we experienced the first isolation of Lactococcus garvieae from a platelet concentrate (PC). Thereafter, L. garvieae contamination of PCs occurred in two more cases in Japan. It is rare that bacterial contamination with uncommon strains like this species occurs frequently within a short period. Therefore, we performed a detailed analysis of the characteristics of these strains.

STUDY DESIGN AND METHODS

Three bacterial strains were identified by biochemical testing and molecular analysis. Genomic diversity was characterized by multilocus sequence typing (MLST). To observe growth kinetics in blood components, PCs were inoculated with the three different strains.

RESULTS

All three strains were identified as L. garvieae by molecular analysis. Each strain belonged to a different phylogenetic group according to MLST analysis. In the spiking trial, the three strains demonstrated differences in their final concentrations and changes in appearance of PCs.

CONCLUSION

In this study, all three L. garvieae strains were correctly identified by molecular analysis. Since the three strains were collected in different regions of Japan and belonged to different phylogenetic groups according to MLST analysis, it is suggested that L. garvieae have a wide distribution with diversity in Japan. In PCs, the three L. garvieae strains showed clear differences in growth kinetics and changes in appearance of PCs. These differences may have been the primary determinant of whether PC contamination was detected before transfusion. Moreover, L. garvieae represents an emerging foodborne bacterium that can cause transfusion-transmitted bacteremia. Understanding our cases may help prevent bacterial contamination of blood products.

Psychrobacter sanguinis Wound Infection Associated with Marine Environment Exposure, Washington, USA

We report a 26-year-old man with Psychrobacter sanguinis cellulitis of a wound sustained during ocean fishing in Washington, USA, in 2017. Psychrobacter spp. are opportunistic pathogens found in a wide range of environments. Clinicians should be aware of Psychrobacter spp. and perform 16S rRNA sequencing if this pathogen is suspected.

Genotypic and phenotypic characteristics of Escherichia coli involved in transfusion-transmitted bacterial infections: implications for preventive strategies

BACKGROUND

Transfusion-transmitted bacterial infections (TTBIs) are the main residual infectious complications of transfusions. Escherichia coli and platelet (PLT) concentrates may be epidemiologically associated, leading to severe, if not lethal, TTBIs. We investigated the genotypic and phenotypic reasons for this clinically deleterious combination.

STUDY DESIGN AND METHODS

We investigated a French national E. coli strain collection related to six independent episodes of TTBIs. Their phenotypic characterizations included antibiotic susceptibility testing, growth testing under different culture conditions, serum survival assays, and virulence in a sepsis mouse model. Their genotypic characterizations included polymerase chain reaction phylotyping, whole genome sequencing, and a subsequent in silico analysis.

RESULTS

We highlighted a selection process of highly extraintestinal virulent strains, mainly belonging to the B2 phylogroup, adapted to the hostile environment (high citrate concentration and a bactericidal serum effect) of apheresis-collected platelet concentrates (PCs). Compared to controls, the E. coli TTBI strains grew faster in the PCs due to a superior ability to capture iron. The in vitro growth performances were highly compatible with blood-derived product real-life conditions, including storage conditions and delays. The consistent serum resistance of TTBI strains promotes their survival in both the donor's and the receiver's blood and in the PCs.

CONCLUSION

This study pointed out that E. coli strains responsible for TTBI exhibit very specific traits. They belong to the extraintestinal pathogenic phylogroups and have a high intrinsic virulence. They can be resistant to complement, capture iron, and grow in the apheresis-collected PCs. These findings therefore support the reinforcement of the postdonation information.

Isolation of bacterial plasmid-related replication-associated circular DNA from a serum sample of a multiple sclerosis patient

Psychrobacter species are considered to be opportunistic human pathogens. We report here the isolation of a circular DNA molecule, MSSI1.162, from a serum sample taken from a multiple sclerosis patient during relapse. This isolate is distantly related to known Psychrobacter species and their plasmids.

Psychrobacter sanguinis: an unusual bacterium for nosocomial meningitis

We report the first case of postneurosurgical meningitis due to Psychrobacter sanguinis, identified only by 16S rRNA analysis. Psychrobacter spp. usually live in deep sea environments and cold habitats. Despite a strict questioning of the patient and the medical staff, we did not find the source of this bacterium.