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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 -
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 -
Fish & Shellfish Immunology Jul 2024The efficacy of phoxim in treating bacterial sepsis in silver carp is significant, yet its underlying mechanism remains elusive. This study aimed to establish a model of...
The efficacy of phoxim in treating bacterial sepsis in silver carp is significant, yet its underlying mechanism remains elusive. This study aimed to establish a model of Aeromonas veronii infection in silver carp and subsequently treat the infected fish with 10 μg/L phoxim. Kidney and intestine samples from silver carp were collected for transcriptome analysis and assessment of intestinal microbial composition, with the aim of elucidating the mechanism underlying the efficacy of phoxim in treating bacterial sepsis in silver carp. The results of transcriptome and intestinal microbial composition analysis of silver carp kidney indicated that A. veronii infection could up-regulate the expression of il1β, il6, nos2, ctsl, casp3 et al., which means, signifying that the kidney of silver carp would undergo inflammation, induce apoptosis, and alter the composition of intestinal microorganisms. Phoxim immersion might enhance the energy metabolism of silver carp and change its intestinal microbial composition, potentially elevating the antibacterial infection resistance of silver carp. These findings may contribute to an understanding of how phoxim can effectively treat bacterial sepsis in silver carp.
Topics: Animals; Carps; Fish Diseases; Organothiophosphorus Compounds; Gram-Negative Bacterial Infections; Aeromonas veronii; Gastrointestinal Microbiome
PubMed: 38750706
DOI: 10.1016/j.fsi.2024.109628 -
Fish Physiology and Biochemistry May 2024This study investigated whether adding Herba Houttuyniae to feed can improve intestinal function and prevent diseases for koi carp (Cyprinus carpio) infected with...
Influence of Herba Houttuyniae added to fodder on the morphological structure of the intestinal tract, the digestive enzymes, the intestinal flora, and immune function of koi carp (Cyprinus carpio) infected with Aeromonas veronii.
This study investigated whether adding Herba Houttuyniae to feed can improve intestinal function and prevent diseases for koi carp (Cyprinus carpio) infected with Aeromonas veronii. There was a total of 168 koi carp with an average body length of (9.43 ± 0.99) cm and an average body weight of (26.00 ± 11.40) g. The K group was the control group fed with basal feed, while the C group was fed with feed with a H. houttuyniae content of six per thousand. After 14 days of feeding, the fish were fasted for a day and then intraperitoneally injected with A. veronii for artificial infection, injection dose is 0.2 mL, and the concentration is 1 × 10 CFU/mL. Samples were collected from the two groups on days 0, 1, 2, and 4. The fold height, intestinal villus width, and muscle layer thickness in the gut of the koi carp were measured. In addition, on day 4, the activities of trypsin, α-amylase, and lipase in the gut were determined, and the intestinal flora of the carp in both groups was tested. The results showed that on the second and fourth days of sampling, the fold height and muscle layer thickness in the C group were significantly higher than those in the K group (P < 0.05). The villus width in the C group was slightly higher than that in the K group, but the difference was not significant (P > 0.05). Microscopic observation revealed that the intestinal structure of the carp in the C4 (day 4 in C group) group was more intact than that in the K4 (day 4 in K group) group. Moreover, the activities of trypsin, α-amylase, and lipase in the foregut and midgut in the C4 group were higher than those in the K4 group (P < 0.05). The activities of trypsin and α-amylase in the hindgut in the C4 group were higher than those in the K4 group (P < 0.05). Furthermore, beneficial bacteria, especially those in the genus Cetobacterium, were more abundant in the intestinal tract of the carp in the C4 group compared to the K group. In addition, comparisons and tests of IL-4 and IL-10 in the intestines of the fish in both groups demonstrated that the H. houttuyniae added to feed enhanced the immune function of the fish intestines after bacterial attack. In conclusion, for koi carp infected with A.veronii, adding H. houttuyniae to their feed not only improves the activity of digestive enzymes and the morphological structure of the intestine but also optimizes the beneficial intestinal microbiota, thereby protecting the intestinal tract.
PubMed: 38696022
DOI: 10.1007/s10695-024-01352-3 -
Frontiers in Medicine 2024Infections in humans are mainly caused by , , and . In recent years, has been recognized as widely distributed in the environment, with strong virulence. However, this...
BACKGROUND
Infections in humans are mainly caused by , , and . In recent years, has been recognized as widely distributed in the environment, with strong virulence. However, this bacterial infection usually does not appear in patients with pneumonia as the first symptom.
CASE REPORT
We report a 26-year-old man who was admitted to the hospital with community-acquired pneumonia as the first symptom and developed serious conditions such as hemolytic uremic syndrome, multiple organ dysfunction, and hemorrhagic shock within a short period. He died after 13 h of admission, and the subsequent metagenomic-next generation sequencing test confirmed the finally identified pathogen of infection as .
CONCLUSION
is a rare pathogen identified in the diagnosis of community-acquired pneumonia. Hence, doctors need to develop their experience in identifying the difference between infections caused by pathogenic microorganisms. Medical attention is essential during the occurrence of respiratory symptoms that could be controlled by empirical drugs, such as cephalosporins or quinolones. When patients with community-acquired pneumonia present hemoptysis and multiple organ dysfunction in clinical treatment, an unusual pathogen infection should be considered, and the underlying etiology should be clarified at the earliest for timely treatment.
PubMed: 38695019
DOI: 10.3389/fmed.2024.1289338 -
Microorganisms Mar 2024is widespread in aquatic environments and is responsible for infecting various aquatic animals. In this study, a dominant strain was isolated from the hepatopancreas of...
is widespread in aquatic environments and is responsible for infecting various aquatic animals. In this study, a dominant strain was isolated from the hepatopancreas of diseased and was named JDM1-1. According to its morphological, physiological, and biochemical characteristics and molecular identification, isolate JDM1-1 was identified as . The results of artificial challenge showed isolate JDM1-1 had high pathogenicity to with an LD value of 8.35 × 10 CFU/mL during the challenge test. Histopathological analysis revealed severe damage in the hepatopancreas and gills of the diseased prawns, characterized by the enlargement of the hepatic tubule lumen and gaps between the tubules as well as clubbing and degeneration observed at the distal end of the gill filament. Eight virulence-related genes, namely , , , , , , , and , were screened by PCR assay. In addition, virulence factor detection showed that the JDM1-1 isolate produced lipase, lecithinase, gelatinase, and hemolysin. Furthermore, the mRNA expression profiles of immune-related genes of following infection, including , , , and were assessed, and the results revealed a significant upregulation in the hepatopancreas and intestines at different hours post infection. This study demonstrates that is a causative agent associated with massive die-offs of and contributes valuable insights into the pathogenesis and host defense mechanisms of invasion.
PubMed: 38674638
DOI: 10.3390/microorganisms12040694 -
Microbiological Research Jul 2024Aeromonas veronii, a significant pathogen in aquatic environments, poses a substantial threat to both human and animal health, particularly in aquaculture. In this...
Complete genome sequence and genome-wide transposon mutagenesis enable the determination of genes required for sodium hypochlorite tolerance and drug resistance in pathogen Aeromonas veronii GD2019.
Aeromonas veronii, a significant pathogen in aquatic environments, poses a substantial threat to both human and animal health, particularly in aquaculture. In this study, we isolated A. veronii strain GD2019 from diseased largemouth bass (Micropterus salmoides) during a severe outbreak of aeromonad septicemia in Guangdong Province, China. The complete genome sequence of A. veronii GD2019 revealed that GD2019 contains a single chromosome of 4703,168 bp with an average G+C content of 58.3%. Phylogenetic analyses indicated that GD2019 forms a separate sub-branch in A. veronii and comparative genomic analyses identified the existence of an intact Type III secretion system. Moreover, to investigate the genes that are required for the conditional fitness of A. veronii under various stresses, a high-density transposon insertion library in GD2019 was generated by a Tn5-based transposon and covers 6311 genomic loci including 4155 genes and 2156 intergenic regions. Leveraging this library, 630 genes were classified as essential genes for growth in rich-nutrient LB medium. Furthermore, the genes GE001863/NtrC and GE002550 were found to confer tolerance to sodium hypochlorite in A. veronii. GE002562 and GE002614 were associated with the resistance to carbenicillin. Collectively, our results provide abundant genetic information on A. veronii, shedding light on the pathogenetic mechanisms of Aeromonas.
Topics: Aeromonas veronii; DNA Transposable Elements; Genome, Bacterial; Animals; Phylogeny; Whole Genome Sequencing; Sodium Hypochlorite; Drug Resistance, Bacterial; Fish Diseases; China; Gram-Negative Bacterial Infections; Bass; Anti-Bacterial Agents; Base Composition; Mutagenesis, Insertional
PubMed: 38653011
DOI: 10.1016/j.micres.2024.127731 -
Chemosphere Jun 2024Aeromonas spp. are frequently encountered in aquatic environments, with Aeromonas veronii emerging as an opportunistic pathogen causing a range of diseases in both...
Aeromonas spp. are frequently encountered in aquatic environments, with Aeromonas veronii emerging as an opportunistic pathogen causing a range of diseases in both humans and animals. Recent reports have raised public health concerns due to the emergence of multidrug-resistant Aeromonas spp. This is particularly noteworthy as these species have demonstrated the ability to acquire and transmit antimicrobial resistance genes (ARGs). In this study, we report the genomic and phenotypic characteristics of the A. veronii TR112 strain, which harbors a novel variant of the Vietnamese Extended-spectrum β-lactamase-encoding gene, bla, and two mcr variants recovered from an urban river located in the Metropolitan Region of São Paulo, Brazil. A. veronii TR112 strain exhibited high minimum inhibitory concentrations (MICs) for ceftazidime (64 μg/mL), polymyxin (8 μg/mL), and ciprofloxacin (64 μg/mL). Furthermore, the TR112 strain demonstrated adherence to HeLa and Caco-2 cells within 3 h, cytotoxicity to HeLa cells after 24 h of interaction, and high mortality rates to the Galleria mellonella model. Genomic analysis showed that the TR112 strain belongs to ST257 and presented a range of ARGs conferring resistance to β-lactams (bla, bla, bla) and polymyxins (mcr-3 and mcr-3.6). Additionally, we identified a diversity of virulence factor-encoding genes, including those encoding mannose-sensitive hemagglutinin (Msh) pilus, polar flagella, type IV pili, type II secretion system (T2SS), aerolysin (AerA), cytotoxic enterotoxin (Act), hemolysin (HlyA), hemolysin III (HlyIII), thermostable hemolysin (TH), and capsular polysaccharide (CPS). In conclusion, our findings suggest that A. veronii may serve as an environmental reservoir for ARGs and virulence factors, highlighting its importance as a potential pathogen in public health.
Topics: beta-Lactamases; Microbial Sensitivity Tests; Humans; Anti-Bacterial Agents; Rivers; Aeromonas veronii; Brazil; HeLa Cells; Caco-2 Cells; Animals; Drug Resistance, Multiple, Bacterial
PubMed: 38614394
DOI: 10.1016/j.chemosphere.2024.141918 -
Frontiers in Veterinary Science 2024is a significant pathogen to various aquatic life. Infections in fish can lead to high mortality rates, causing substantial economic losses in aquaculture. Vaccination...
INTRODCTION
is a significant pathogen to various aquatic life. Infections in fish can lead to high mortality rates, causing substantial economic losses in aquaculture. Vaccination is proposed as a substitute for antibiotics in aquaculture to decrease disease-related mortality and morbidity. Our study previously constructed a -deleted strain of , which provided protective effect to .
METHODS
To further assess the vaccine's applicability, this study evaluated its genetic stability and safety, and the immune protective effects in through four distinct administration routes: intraperitoneal injection, intramuscular injection, oral administration, and immersion, to determine the efficacy of these administration routes.
RESULTS
The results showed that the vaccine remained genetically stable after 45 generations. Immunization via these administration routes was safe for , with intraperitoneal and intramuscular injections causing stronger adverse reactions. Immersion immunization resulted in mild adverse reactions, and no significant adverse reactions were observed following oral immunization. Immunizing at safe concentrations via these routes enhanced the phagocytic activity in serum, increased the levels of non-specific immune-related enzymes (ACP, AKP, C3, C4, LZM, SOD, and IgM), and improved specific serum antibody levels. It also elevated levels of cytokines related to inflammatory responses (IL-1β, IL-10, TNF-α, TGF-β) in organ tissues (liver, spleen, kidney, mid-post intestine, and gills). The survival rates of were measured after challenging with the virulent strain , resulting in the relative survival rates of 64% for Intraperitoneal vaccine group, 56% for Intramuscular vaccine group, 52% for oral vaccine group, and 48% for immersion vaccine group. Analysis of bacterial load in the liver, spleen, and kidney post-challenge showed a decreasing trend in the control group, indicating that the vaccine strain could gradually restrict the rapid proliferation of bacteria in these tissues, thereby providing a certain level of immune protection against .
DISCUSSION
In brief, the vaccine strain can serve as a safe live attenuated vaccine for , and this study lays the foundation for the development of live attenuated vaccines against .
PubMed: 38577546
DOI: 10.3389/fvets.2024.1378448 -
Microbiology Resource Announcements May 2024Extended-spectrum beta-lactamase, AmpC, and carbapenemase-producing bacteria were isolated from raw sewage, effluent, oxidation pond water, and sediment from a...
Extended-spectrum beta-lactamase, AmpC, and carbapenemase-producing bacteria were isolated from raw sewage, effluent, oxidation pond water, and sediment from a wastewater treatment plant in Aotearoa New Zealand. Here, we report the assemblies of 17 isolates belonging to the species , , , , , , , , , and .
PubMed: 38564672
DOI: 10.1128/mra.00131-24