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Frontiers in Pediatrics 2024infection of the bloodstream and intestine is a rare and severe opportunistic infection in immunocompromised people. In Southwest China, we first reported a case of...
infection of the bloodstream and intestine is a rare and severe opportunistic infection in immunocompromised people. In Southwest China, we first reported a case of bloodstream and intestinal infection with multidrug-resistant (MDR) in a 4-year-old child with T-cell acute lymphoblastic leukemia. Blood and stool cultures were used to identify the infection. The selection of antibiotics was based on clinical expertise and medication sensitivity tests. We used linezolid, levofloxacin, and polymyxin B to treat the patient aggressively. infection is uncommon in juvenile acute lymphoblastic leukemia. Doctors should be aware of the likelihood of opportunistic infection during the post-chemotherapy bone marrow suppression period. We further conducted a review of the literature and performed a detailed analysis of s infection in pediatric leukemia. It is becoming increasingly apparent that antibiotic is abused domestically and abroad, resulting in the sharp increase of MDR bacteria. In general, most of the isolates are susceptible to third- or fourth-generation cephalosporins, aminoglycosides, quinolones, and carbapenem, but drug-resistant strains are being reported increasingly. We summarized the drug resistance rate of s caviae and in China in the last 10 years. Early recognition and effective treatment will improve prognosis and reduce mortality.
PubMed: 38803640
DOI: 10.3389/fped.2024.1233600 -
BMC Veterinary Research May 2024Moringa oleifera, a well-known medicinal plant, has been used in aquafeed as a dietary supplement. Based on previous studies, insufficient research is available on the...
Immunomodulatory, antioxidant, and growth-promoting activities of dietary fermented Moringa oleifera in Nile tilapia (Oreochromus niloticus) with in-vivo protection against Aeromonas hydrophila.
BACKGROUND
Moringa oleifera, a well-known medicinal plant, has been used in aquafeed as a dietary supplement. Based on previous studies, insufficient research is available on the dietary supplementation of Nile tilapia with M. oleifera leaf and seed mixtures, specifically the fermented form. Therefore, this study aimed to investigate the efficacy of fermented (FMO) versus non-fermented M. oleifera (MO) leaf and seed mixtures on immunological parameters, antioxidant activity, growth performance, and resistance to A. hydrophila infection after a 30-day feeding trial on Nile tilapia.
METHODS
A total of 180 fingerlings were randomly divided into four groups in addition to the control group (36 fish each, in triplicate). Fish in the tested groups were fed on basal diet supplemented with MO5%, MO10%, FMO5%, and FMO10%, while those in control were fed on basal diet only. After the feeding trial, fish were challenged with A. hydrophila. The immunomodulatory activity of M. oleifera was evaluated in terms of phagocytic and lysozyme activities, immune-related cytokines and IgM gene expression. Antioxidants, and growth-promoting activities were also assessed.
RESULTS
The results revealed that fish supplemented FMO markedly in FMO10% group followed by FMO5%, exhibited significant (P < 0.05) improvement in the tested immunological, hepatic antioxidants, and growth performance parameters. Furthermore, the highest survival rate post-challenge with mild clinical symptoms, and the lowest A. hydrophila bacterial count were reported in these groups. Meanwhile, MO10%-supplementation exhibited the opposite trend.
CONCLUSIONS
The study' conclusion suggests that fermented M. oleifera leaf and seed mixture is a promising growth-promoting and immunostimulatory feed-additive candidate for Nile tilapia and could reduce the losses caused by A. hydrophila infection.
Topics: Animals; Moringa oleifera; Aeromonas hydrophila; Cichlids; Gram-Negative Bacterial Infections; Antioxidants; Animal Feed; Fish Diseases; Diet; Dietary Supplements; Plant Leaves; Fermentation; Seeds
PubMed: 38802892
DOI: 10.1186/s12917-024-04070-3 -
Frontiers in Immunology 2024, a bacterium widely distributed in the natural environment, causes multiple diseases in various animals. Exploring the mechanism of the host defense against can help...
Integrated time-series biochemical, transcriptomic, and metabolomic analyses reveal key metabolites and signaling pathways in the liver of the Chinese soft-shelled turtle () against infection.
INTRODUCTION
, a bacterium widely distributed in the natural environment, causes multiple diseases in various animals. Exploring the mechanism of the host defense against can help develop efficient strategies against infection.
METHODS
Herein, we investigated the temporal influence of A. hydrophila on the Chinese soft-shelled turtle, an economically important species, at the biochemical, transcriptomic, and metabolomic levels. Plasma parameters were detected with the test kits. Transcriptome and metabolome were respectively applied to screen the differentially expressed genes and metabolites.
RESULTS
The contents or activities of these plasma parameters were significantly increased at 24 hpi and declined at 96 hpi, indicating that 24 and 96 hpi were two important time points during infection. Totals of 3121 and 274 differentially expressed genes (DEGs) from the transcriptome while 74 and 91 differentially abundant metabolites (DAMs) from the metabolome were detected at 24 and 96 hpi. The top DEGs at 24 hpi included and while and were the most abundant at 96 hpi. The predominant DAMs included O-phospho-L-serine, γ-Aminobutyric acid, orotate, L-tyrosine, and L-tryptophan at 24 hpi, as well as L-glutamic acid, L-arginine, glutathione, glutathione disulfide, and citric acid at 96 hpi.
DISCUSSION
The combined analysis of DEGs and DAMs revealed that tryptophan metabolism, nicotinate and nicotinamide metabolism, as well as starch and sucrose metabolism, were the most important signaling pathways at the early infective stage while tyrosine metabolism, pyrimidine metabolism, as well as alanine, aspartate and glutamate metabolism were the most crucial pathways at the later stage. In general, our results indicated that the Chinese soft-shelled turtle displays stage-specific physiological responses to resist infection.
Topics: Animals; Turtles; Aeromonas hydrophila; Gram-Negative Bacterial Infections; Signal Transduction; Metabolomics; Liver; Metabolome; Transcriptome; Gene Expression Profiling
PubMed: 38799475
DOI: 10.3389/fimmu.2024.1376860 -
Microorganisms Apr 2024In contrast to "frank" pathogens, like , , and , that always have a probability of disease, "opportunistic" pathogens are organisms that cause an infectious disease in a... (Review)
Review
In contrast to "frank" pathogens, like , , and , that always have a probability of disease, "opportunistic" pathogens are organisms that cause an infectious disease in a host with a weakened immune system and rarely in a healthy host. Historically, drinking water treatment has focused on control of frank pathogens, particularly those from human or animal sources (like , , or ), but in recent years outbreaks from drinking water have increasingly been due to opportunistic pathogens. Characteristics of opportunistic pathogens that make them problematic for water treatment include: (1) they are normally present in aquatic environments, (2) they grow in biofilms that protect the bacteria from disinfectants, and (3) under appropriate conditions in drinking water systems (e.g., warm water, stagnation, low disinfectant levels, etc.), these bacteria can amplify to levels that can pose a public health risk. The three most common opportunistic pathogens in drinking water systems are , , and . This report focuses on these organisms to provide information on their public health risk, occurrence in drinking water systems, susceptibility to various disinfectants, and other operational practices (like flushing and cleaning of pipes and storage tanks). In addition, information is provided on a group of nine other opportunistic pathogens that are less commonly found in drinking water systems, including , , , , , , , and several free-living amoebae including and species of The public health risk for these microbes in drinking water is still unclear, but in most cases, efforts to manage , mycobacteria, and risks will also be effective for these other opportunistic pathogens. The approach to managing opportunistic pathogens in drinking water supplies focuses on controlling the growth of these organisms. Many of these microbes are normal inhabitants in biofilms in water, so the attention is less on eliminating these organisms from entering the system and more on managing their occurrence and concentrations in the pipe network. With anticipated warming trends associated with climate change, the factors that drive the growth of opportunistic pathogens in drinking water systems will likely increase. It is important, therefore, to evaluate treatment barriers and management activities for control of opportunistic pathogen risks. Controls for primary treatment, particularly for turbidity management and disinfection, should be reviewed to ensure adequacy for opportunistic pathogen control. However, the major focus for the utility's opportunistic pathogen risk reduction plan is the management of biological activity and biofilms in the distribution system. Factors that influence the growth of microbes (primarily in biofilms) in the distribution system include, temperature, disinfectant type and concentration, nutrient levels (measured as AOC or BDOC), stagnation, flushing of pipes and cleaning of storage tank sediments, and corrosion control. Pressure management and distribution system integrity are also important to the microbial quality of water but are related more to the intrusion of contaminants into the distribution system rather than directly related to microbial growth. Summarizing the identified risk from drinking water, the availability and quality of disinfection data for treatment, and guidelines or standards for control showed that adequate information is best available for management of . For , the risk for this organism has been clearly established from drinking water, cases have increased worldwide, and it is one of the most identified causes of drinking water outbreaks. Water management best practices (e.g., maintenance of a disinfectant residual throughout the distribution system, flushing and cleaning of sediments in pipelines and storage tanks, among others) have been shown to be effective for control of in water supplies. In addition, there are well documented management guidelines available for the control of the organism in drinking water distribution systems. By comparison, management of risks for from water are less clear than for . Treatment of is difficult due to its resistance to disinfection, the tendency to form clumps, and attachment to surfaces in biofilms. Additionally, there are no guidelines for management of in drinking water, and one risk assessment study suggested a low risk of infection. The role of tap water in the transmission of the other opportunistic pathogens is less clear and, in many cases, actions to manage (e.g., maintenance of a disinfectant residual, flushing, cleaning of storage tanks, etc.) will also be beneficial in helping to manage these organisms as well.
PubMed: 38792751
DOI: 10.3390/microorganisms12050916 -
International Journal of Molecular... May 2024can be a substantial concern, as it causes various diseases in aquaculture. An effective and green method for inhibiting is urgently required. Emodin, a naturally...
can be a substantial concern, as it causes various diseases in aquaculture. An effective and green method for inhibiting is urgently required. Emodin, a naturally occurring anthraquinone compound, was exploited as a photo-antimicrobial agent against . At the minimum inhibitory concentration of emodin (256 mg/L) to inactivate in 30 min, an 11.32% survival rate was observed under 45 W white compact fluorescent light irradiation. In addition, the antibacterial activity under natural sunlight (0.78%) indicated its potential for practical application. Morphological observations demonstrated that the cell walls and membranes of were susceptible to damage by emodin when exposed to light irradiation. More importantly, the photoinactivation of was predominantly attributed to the hydroxyl radicals and superoxide radicals produced by emodin, according to the trapping experiment and electron spin resonance spectroscopy. Finally, a light-dependent reactive oxygen species punching mechanism of emodin to photoinactivate was proposed. This study highlights the potential use of emodin in sunlight-mediated applications for bacterial control, thereby providing new possibilities for the use of Chinese herbal medicine in aquatic diseases prevention.
Topics: Emodin; Aeromonas hydrophila; Sunlight; Anti-Bacterial Agents; Microbial Sensitivity Tests; Reactive Oxygen Species
PubMed: 38791482
DOI: 10.3390/ijms25105444 -
Pathogens (Basel, Switzerland) Apr 2024is a widely recognized broad-spectrum pathogen that primarily targets the gastrointestinal tract. Type IV pili (T4P) are proteinaceous nano-machines located on the...
BACKGROUND
is a widely recognized broad-spectrum pathogen that primarily targets the gastrointestinal tract. Type IV pili (T4P) are proteinaceous nano-machines located on the bacterial cell surface, playing a crucial role in host colonization and infection. Regrettably, the T4P systems of remain largely underexplored.
METHODS
genomes with complete genome assembly and annotation reports up to 31 March 2023, were obtained from the NCBI Genome database or KEGG genome database, followed by a global search for T4P secretion system genes. Protein sequences of these manually curetted genes were used as secondary quarry for Synteny analysis. Protein-protein interaction analysis was performed by string analysis and in silico study of genomic islands.
RESULTS
We identified 27 orthologs of type IV pili (T4P) nano-machine components in . These orthologs are primarily distributed across three operons: pilABCD, pilMNOPQ, and pilVWXY. While the first two operons are commonly found in all experimental genomes, the presence of the pilVWXY operon, coding for 11 orthologs, is reported here for the first time in . Notably, the complete pilVWXY operon is absent in nonvirulent strains. A genomic islands study between a nonvirulent and hypervirulent strain also confirms absence of most of the genes coded by pilVWXY in nonvirulent strain. Interestingly, among the 51 experimental genomes analyzed, the pilVWXY operon was completely absent in 10 strains, most of which are categorized as nonvirulent; Conclusions: The distribution of two major type IV pili (T4P) nano-machines, PilABCDMNOPQ and PilVWXY, is reported here for the first time in . Additionally, this study suggests a potential role for the PilVWXY nano-machine in establishing human disease.
PubMed: 38787217
DOI: 10.3390/pathogens13050365 -
Annals of Clinical Microbiology and... May 2024The population structure and the correlation between antimicrobial resistance (AMR) phenotypes and genotypes in Aeromonas species isolated from patients with...
BACKGROUND
The population structure and the correlation between antimicrobial resistance (AMR) phenotypes and genotypes in Aeromonas species isolated from patients with gastroenteritis are not well understood. The aims of the study were to: (1) investigate the antimicrobial susceptibility profiles of Aeromonas species isolated from patients with gastroenteritis; (2) explore the relationship between AMR genes and resistance phenotypes; and (3) describe the population structure of these isolates and provide evidence of transmission events among them.
METHODS
This microbiological survey was performed at the Microbiology Laboratory of the Emek Medical Center in Afula, Israel. Cultivation of Aeromonas was attempted from stool samples that tested positive by PCR. Antimicrobial susceptibility testing (AST) was performed using the Sensititre GN3F microdilution panel. Whole genome sequencing (WGS) was done using the Illumina NextSeq500/550 system. Phylogenetic studies involved multi-locus sequence typing (MLST) and core genome (cg) MLST. Resistance mechanisms were identified using the Comprehensive Antibiotic Resistance Database and compared with the AST results.
RESULTS
The study included 67 patient-unique isolates. The species that were identified included A. caviae (n = 58), A. dhakensis (n = 3), A. media (n = 2), A. veronii (n = 2) and A. hydrophila (n = 2). Isolates were almost uniformly susceptible to amikacin, gentamicin, aztreonam, cefepime, ceftazidime, ciprofloxacin and meropenem. All isolates with the exception of 1-2 isolates were resistant to ampicillin, cefazolin and ampicillin-sulbactam which was compatible with the presence of the bla genes. Variable resistance rates were observed to cefuroxime, cefoxitin, ceftriaxone, piperacillin-tazobactam that were not correlated with the presence of other β-lactamase genes. Resistance to tetracycline and trimethoprim-sulfamethoxazole correlated with the presence of tetA and sul1, respectively. The population structure of A. caviae was highly diverse with the minority of the isolates (16/57) clustering into six defined sequence types. A cgMLST-based distance of four genes was found in one pair of isolates, suggesting common source transmission.
CONCLUSIONS
A. caviae is the dominant species related to gastroenteritis and is characterized by a diverse population structure, with almost no evidence for common-source transmission. Resistance rates to most antimicrobial agents were low and partially matched with the presence of resistance genes.
Topics: Humans; Gastroenteritis; Aeromonas; Microbial Sensitivity Tests; Anti-Bacterial Agents; Genotype; Phylogeny; Gram-Negative Bacterial Infections; Whole Genome Sequencing; Multilocus Sequence Typing; Child; Phenotype; Adult; Feces; Child, Preschool; Female; Male; Middle Aged; Drug Resistance, Bacterial; Israel; Aged; Infant; Adolescent; Young Adult; Drug Resistance, Multiple, Bacterial
PubMed: 38783344
DOI: 10.1186/s12941-024-00706-2 -
Probiotics and Antimicrobial Proteins May 2024This study evaluated the effects of Technospore® (Bacillus coagulans) supplementation on intestinal health, immune response, and Oreochromis niloticus (Nile tilapia)...
Probiotic Efficacy in Aquaculture: The Role of Technospore® (Bacillus coagulans) in Improving Nile Tilapia (Oreochromis niloticus) Performance and Disease Resistance: a Study on Gut Health, Immunological Response, and Gene Expression.
This study evaluated the effects of Technospore® (Bacillus coagulans) supplementation on intestinal health, immune response, and Oreochromis niloticus (Nile tilapia) growth performance. The experiment divided fish into four groups: a control group fed an unsupplemented diet and three experimental groups receiving diets supplemented with 0.2 g/kg, 0.4 g/kg, and 0.8 g/kg of Technospore®, respectively. Results indicated that Technospore® supplementation significantly enhanced growth rates and feed efficiency in all treated groups, with the most pronounced improvements observed in the group receiving 0.4 g/kg. Furthermore, the study revealed that B. coagulans supplementation markedly boosted serum immune responses, as evidenced by increased phagocytic activity, phagocytic index, and lysozyme levels, following a challenge with Aeromonas hydrophila. Histological analysis showed improved gut morphology, while gene expression analysis indicated upregulation of immune-related genes, including liver IGF-1, GHR, HSP70, IL-1β, and TNF-α, as well as spleen TNF-α and IL-1β and intestinal C-lysozyme and TNF-α, both before and after the bacterial challenge. These findings suggest that dietary inclusion of Technospore® can significantly improve gut health and immune responses in tilapia, potentially serving as an effective prophylactic alternative to antibiotics in aquaculture.
PubMed: 38771456
DOI: 10.1007/s12602-024-10279-3 -
BioRxiv : the Preprint Server For... May 2024Marine bacteria experience fluctuations in osmolarity that they must adapt to, and most bacteria respond to high osmolarity by accumulating compatible solutes also known...
UNLABELLED
Marine bacteria experience fluctuations in osmolarity that they must adapt to, and most bacteria respond to high osmolarity by accumulating compatible solutes also known as osmolytes. The osmotic stress response and compatible solutes used by the coral and oyster pathogen were unknown. In this study, we showed that to alleviate osmotic stress biosynthesized glycine betaine (GB) and transported into the cell choline, GB, ectoine, dimethylglycine, and dimethylsulfoniopropionate, but not -inositol. -inositol is a stress protectant and a signaling molecule that is biosynthesized and used by algae. Bioinformatics identified -inositol ( ) catabolism clusters in and other and species. Growth pattern analysis demonstrated that utilized -inositol as a sole carbon source, with a short lag time of 3 h. An deletion mutant, which encodes an inositol dehydrogenase, was unable to grow on -inositol. Within the clusters were an MFS-type ( and an ABC-type ( transporter and analyses showed that both transported -inositol. IolG and IolA phylogeny among species showed different evolutionary histories indicating multiple acquisition events. Outside of , IolG was most closely related to IolG from a small group of fish and human pathogens and species. However, IolG from hypervirulent strains clustered with IolG from and divergently from and plant pathogens. The cluster was also present within and of which many species were associated with marine flora and fauna.
IMPORTANCE
Host associated bacteria such as encounter competition for nutrients and have evolved metabolic strategies to better compete for food. Emerging studies show that -inositol is exchanged in the coral-algae symbiosis, is likely involved in signaling, but is also an osmolyte in algae. The bacterial consumption of -inositol could contribute to a breakdown of the coral-algae symbiosis during thermal stress or disrupt the coral microbiome. Phylogenetic analyses showed that the evolutionary history of -inositol metabolism is complex, acquired multiple times in but acquired once in many bacterial plant pathogens. Further analysis also showed that a conserved cluster is prevalent among many marine species (commensals, mutualists, and pathogens) associated with marine flora and fauna, algae, sponges, corals, molluscs, crustaceans, and fish.
PubMed: 38766061
DOI: 10.1101/2024.01.16.575920 -
Acta Tropica Aug 2024Aeromonas spp. are normal inhabitants of aquatic environments and are emerging foodborne bacterial pathogens. Aeromonas spp. contamination is frequent in ready-to-eat...
Aeromonas spp. are normal inhabitants of aquatic environments and are emerging foodborne bacterial pathogens. Aeromonas spp. contamination is frequent in ready-to-eat (RTE) seafood and can also occur in products prepared from milk or meat. The study determined the enterotoxin and antimicrobial susceptibility profiles of Aeromonas spp. isolates recovered from RTE milk products (n = 105), RTE meat/fish products (n = 40) and drinking water (n = 60) samples collected from tourist places in Himachal Pradesh, India, in northwestern Himalayas. 7.3 % (16/220) samples were found contaminated with Aeromonas spp. These isolates were identified as A. hydrophila (31.3 %), A. schubertii (25.0 %), A. sobria (25.0 %) and A. veronii (18.8 %). Aeromonas spp. contamination was significantly higher (14.3 %, 15/105, p = 0.0001) in RTE milk products. The contamination levels for water samples were 1.7 % whereas none of the tested RTE meat or fish products yielded Aeromonas spp. Among RTE milk products, contamination was significantly higher in paneer (South Asian soft cheese) (26.1 %, p = 0.0027) and cream (25.0 %, p = 0.046) based RTE foods. All isolates carried alt (361 bp), encoding a cytotonic heat-labile enterotoxin. Ampicillin resistance was 100 % and high levels (>30 %) of resistance were recorded for amoxicillin/clavulanic acid, amikacin, cefotaxime and ceftazidime. Six (37.5 %) isolates were multi drug resistant (MDR), showing resistance to aminoglycosides, cephams and penicillins. Isolation of alt carrying MDR isolates from RTE foods indicates that Aeromonas spp. can be potential foodborne public health threat in northwestern Himalayas.
Topics: Aeromonas; Enterotoxins; India; Drug Resistance, Multiple, Bacterial; Microbial Sensitivity Tests; Anti-Bacterial Agents; Food Microbiology; Animals; Humans; Public Health; Seafood; Himalayas
PubMed: 38759830
DOI: 10.1016/j.actatropica.2024.107258