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Journal of Fish Diseases Aug 2022Motile Aeromonas septicemia (MAS), a disease caused by Aeromonas spp., is recognized as a major disease in freshwater aquaculture. This study aimed to investigate the...
Motile Aeromonas septicemia (MAS), a disease caused by Aeromonas spp., is recognized as a major disease in freshwater aquaculture. This study aimed to investigate the distribution and diversity of Aeromonas spp. and their antimicrobial susceptibility patterns. A total of 86 isolates of Aeromonas spp. were recovered from diseased freshwater fishes from 13 farms in Thailand. All isolates were identified using biochemical characteristics, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), polymerase chain reaction assays, and the gyrB gene sequence analysis. The result of MALDI-TOF MS showed 100% (86 isolates) accuracy at genus-level identification, and 88.4% (76 isolates) accuracy at species-level identification. Six species of Aeromonas were confirmed through nucleotide sequencing and phylogenetic analysis of the gyrB gene Aeromonas veronii (72.1%), Aeromonas jandaei (11.6%), Aeromonas schubertii (9.3%), Aeromonas diversa (3.5%), Aeromonas hydrophila (2.3%), and Aeromonas punctata (1.2%). Antimicrobial susceptibility tests for all isolates revealed resistance against amoxicillin (99%), ampicillin (98%), oxolinic acid (81.4%), oxytetracycline (77%), trimethoprim-sulfamethoxazole (24%), and enrofloxacin (21%). The multiple antibiotic resistance (MAR) index varied between 0.14 and 0.86, with MAR values more than 0.2 in 99% of isolates. Furthermore, four diverse multidrug-resistant (MDR) patterns were found among Aeromonas isolates. Our finding show that A. veronii is the most abundant species in Thai cultured freshwater fish with the highest MDR patterns.
Topics: Aeromonas; Animals; Anti-Bacterial Agents; Fish Diseases; Fishes; Fresh Water; Microbial Sensitivity Tests; Phylogeny; Thailand
PubMed: 35598068
DOI: 10.1111/jfd.13650 -
Frontiers in Public Health 2021Aeromonads are aquatic bacteria associated with frequent outbreaks of diarrhea in coastal Bangladesh, but their potential risks from environmental sources have remained...
Aeromonads are aquatic bacteria associated with frequent outbreaks of diarrhea in coastal Bangladesh, but their potential risks from environmental sources have remained largely unexplored. This study, over 2 years, examined homestead pond waters in the region for monthly dynamics and diversity of spp. The bacterial counts showed bi-modal annual growth peak, pre- and post-monsoon, strongly correlating ( < 0.0005) with temperature. Of 200 isolates characterized, bv. sobria (27%) was predominant among co-existent (20%), (17%), (13%), and three more. PCR screening of virulence-related genes identified 15 genotypes (I to XV), however, enterotoxigenicity in animal model was observed for five genotypes, ca. 18% (nine of 50) strains, prevalent in bv. sobria, , and . Pathogenic strains were distinguishable by possessing at least three of the major virulence genes: , and , together with accessory virulence factors. PFGE of I-digested genomic DNA revealed high genetic diversity and distant lineage of potentially toxigenic clones. Therefore, along with increased global warming, spp. having multi-factorial virulence potential in coastal ponds that serve as drinking water sources pose a potential health risk, and underscores the need for routine monitoring.
Topics: Aeromonas; Animals; Bangladesh; Ponds; Virulence; Water
PubMed: 34307285
DOI: 10.3389/fpubh.2021.692166 -
Journal of Clinical Microbiology Aug 1989Recent studies have resulted in the proposal of a new species, Aeromonas schubertii (mannitol, sucrose, and indole negative), formerly termed Enteric Group 501, on the...
Recent studies have resulted in the proposal of a new species, Aeromonas schubertii (mannitol, sucrose, and indole negative), formerly termed Enteric Group 501, on the basis of the study of seven strains isolated from the southeastern and southwestern United States and Puerto Rico. We have isolated two phenotypically similar A. schubertii strains from infected human wounds sustained in the Chesapeake Bay area. Their identification was confirmed by DNA-DNA hybridization to the Centers for Disease Control definition strain 2446-81 (ATCC 43700) for group 12. The strains were further examined for the presence of virulence-associated markers: hemolysin, hemagglutinins, cytotoxin production, agglutination in acriflavine, resistance to normal human serum, and autoagglutination phenotype. Both strains were positive for hemolysin by the plate assay, cytotoxin production at 1:10, and DNase and protease. They were resistant to human serum and negative for acriflavine agglutination, and only one of the strains was autoagglutination positive. Both strains were negative for cell-free hemolysin, hemagglutinins, pectinase, and chitinase. These isolations of A. schubertii further extend its previously described geographic distribution and reinforce its role as a primary causative agent of cellulitis with possible increased antimicrobial resistance.
Topics: Aeromonas; Anti-Bacterial Agents; Baltimore; DNA, Bacterial; Female; Hemagglutinins; Hemolysin Proteins; Humans; Male; Middle Aged; Virulence; Wound Infection
PubMed: 2768470
DOI: 10.1128/jcm.27.8.1826-1830.1989 -
The American Journal of Emergency... Jan 2012Necrotizing fasciitis is an uncommon but life-threatening condition with a high associated mortality and morbidity. Most infections are polymicrobial, another distinct...
Necrotizing fasciitis is an uncommon but life-threatening condition with a high associated mortality and morbidity. Most infections are polymicrobial, another distinct form of necrotizing fasciitis that occurred by penetrating freshwater trauma, such as fishing or wading in wet fields. Aeromonas species are responsible. The rapidity of the infectious process is similar to that of clostridial infection, but gas production is not a consistent feature. We report a patient who presented with fever, chills, and bullae on left forearm, despite antibiotics and wound debridement; the infection extend to mid humerus with a rapid onset of skin necrosis and progressive sepsis. Aeromonas schubertii fasciitis is particularly virulent. An apparent superficial cellulitis that fails to respond to standard therapy must raise suspicion of a more extensive underlying subcutaneous infection. Aggressive surgical debridement and antibiotic coverage for gram-negative rods are the essential features of treatment. Delay caused by a mistaken diagnosis of cellulitis and subsequent inadequate debridement would likely prove fatal.
Topics: Aeromonas; Aged; Fasciitis, Necrotizing; Fatal Outcome; Gram-Negative Bacterial Infections; Hand Injuries; Humans; Male; Wound Infection; Wounds, Penetrating
PubMed: 21247722
DOI: 10.1016/j.ajem.2010.10.028 -
Veterinary World Jan 2022Antibiotic resistance has been a progressively documented problem, resulting in treatment failure in humans and animals. This study aimed to investigate the...
BACKGROUND AND AIM
Antibiotic resistance has been a progressively documented problem, resulting in treatment failure in humans and animals. This study aimed to investigate the antimicrobial susceptibility and virulence of extensively drug-resistant (XDR) spp. in wild and its surrounding seawater along the coastal road of Port Said, Egypt.
MATERIALS AND METHODS
Specimens were examined bacteriologically, confirmed biochemically, and tested for their sensitivity against 11 antimicrobial agents. Molecular confirmation of the obtained isolates by was performed, followed by the detection of antimicrobial resistance and virulence genes.
RESULTS
spp. was recovered from fish (44%) and water samples (36%). was the most prevalent identified strain, followed by , , and . Moreover, 90% of the tested isolates were multidrug-resistant (MDR), while 26.67% were XDR. Tested isolates were resistant to b-lactams and sulfonamides (100%), oxytetracycline (90%), and streptomycin (62.22%) but completely susceptible to cefotaxime. XDR isolates successfully amplified resistance genes (, and ()) but not the () gene, although there was phenotypic resistance to streptomycin on plates. All XDR isolates carry the cytotoxic enterotoxin gene (), but gene was detected in only one isolate (12.5%).
CONCLUSION
Data in this study provide a recent update and highlight the role of wild mullet and seawater as reservoirs for MDR and XDR spp. that may pose a risk to humans as food-borne infection or following direct contact.
PubMed: 35369605
DOI: 10.14202/vetworld.2022.55-64 -
International Journal of Systematic and... Mar 2004Two Aeromonas strains, IBS S6874(T) and IBS S6652, were isolated from the faeces of two healthy monkeys (Macaca fascicularis) from Mauritius that were kept in quarantine...
Two Aeromonas strains, IBS S6874(T) and IBS S6652, were isolated from the faeces of two healthy monkeys (Macaca fascicularis) from Mauritius that were kept in quarantine in the Centre for Primatology, Strasbourg, France. Phylogenetic analysis based on 16S rRNA gene sequences showed that the two isolates formed an unknown genetic lineage within the genus Aeromonas. The two isolates had nearly identical sequences (0.1 % nucleotide substitution) that were related closely to those of recognized Aeromonas species (1.7-3.5 % nucleotide substitution). DNA-DNA hybridization showed that strains IBS S6874(T) and IBS S6652 had high DNA-DNA similarity (89 %) to each other and a low level of DNA-DNA similarity to closely related taxa (18 % relatedness to Aeromonas trota and 16 % relatedness to Aeromonas schubertii). Phenotypically, the two monkey isolates differed from most previously described mesophilic Aeromonas species by their lack of haemolysis on sheep-blood agar and inability to produce indole, gas from glucose or acid from mannitol. They differed from the most closely related species, A. schubertii, by their ability to produce acid from D-cellobiose and D-sucrose and by their pyrazinamidase activity. The name Aeromonas simiae sp. nov. is proposed for these isolates; strain IBS S6874(T) (=CIP 107798(T)=CCUG 47378(T)) is the type strain.
Topics: Aeromonas; Animals; DNA, Bacterial; DNA, Ribosomal; Feces; Macaca fascicularis; Mauritius; Molecular Sequence Data; Nucleic Acid Hybridization; Phylogeny; RNA, Bacterial; RNA, Ribosomal, 16S
PubMed: 15023964
DOI: 10.1099/ijs.0.02786-0 -
Revista Da Sociedade Brasileira de... 2008Aeromonas spp is recognized as pathogenic to humans after consumption of contaminated water and food. In the present investigation, 2,323 rectal swab samples from...
Aeromonas spp is recognized as pathogenic to humans after consumption of contaminated water and food. In the present investigation, 2,323 rectal swab samples from newborns hospitalized in Rio de Janeiro were evaluated with a view to isolating Aeromonas. The samples were collected and sent to the national reference laboratory for cholera and other bacterial intestinal infections, at the Oswaldo Cruz Institute of the Oswaldo Cruz Foundation. The swabs were subjected to enrichment in alkaline peptonated water with the addition of 1% sodium chloride (NaCl) and alkaline peptonated water plus 3% NaCl (37 degrees C/18-24h) and were streaked onto agar that was selective for Pseudomonas-Aeromonas (GSP Agar). Fifty-six Aeromonas strains were isolated, distributed as follows: Aeromonas caviae (42.8%), Aeromonas media (25%), Aeromonas veronii biogroup sobria (10.7%), Aeromonas hydrophila (9%), Aeromonas veronii biogroup veronii (5.3%), Aeromonas sobria (1.8%), Aeromonas jandaei (1.8%), Aeromonas schubertii (1.8%) and Aeromonas sp (1.8%). Resistance to one or more antimicrobial drugs was observed in 26.8% of the strains. Considering the importance of Aeromonas, there is an urgent need to warn about this in relation to nosocomial infection control.
Topics: Aeromonas; Anti-Bacterial Agents; Drug Resistance, Microbial; Humans; Infant, Newborn; Microbial Sensitivity Tests; Rectum
PubMed: 18545840
DOI: 10.1590/s0037-86822008000200009 -
International Journal of Systematic and... Oct 2006Recent phylogenetic studies of the genus Aeromonas based on gyrB and rpoD gene sequences have improved the phylogeny based on 16S rRNA gene sequences first published in...
Recent phylogenetic studies of the genus Aeromonas based on gyrB and rpoD gene sequences have improved the phylogeny based on 16S rRNA gene sequences first published in 1992, particularly in the ability to split closely related species. These studies did not include the recently described species Aeromonas simiae and Aeromonas molluscorum and only a single strain of Aeromonas culicicola was available for analysis at that time. In the present work, these Aeromonas species and newly isolated strains of A. culicicola were examined. Sequence analysis indicates that A. simiae and A. molluscorum belong to non-described phylogenetic lines of descent within this genus, which supports the original description of both species. The most closely related species are Aeromonas schubertii and Aeromonas encheleia, respectively, which is consistent with 16S rRNA gene sequencing results. However, while the five strains of A. molluscorum showed nucleotide differences in their gyrB and rpoD gene sequences, the only two known A. simiae strains exhibited identical gene sequences, suggesting that they are isolates of the same strain. On the basis of the rpoD gene sequence phylogeny, A. culicicola strains from the original description and new isolates from drinking water and ornamental fish clustered within the species Aeromonas veronii, suggesting inconsistencies with previous results. Other strains with previously controversial taxonomy and new isolates from other studies were included in this study in order to clarify their phylogenetic affiliation at the species level.
Topics: Aeromonas; Animals; Bacterial Typing Techniques; DNA Gyrase; DNA, Bacterial; DNA-Directed RNA Polymerases; Humans; Molecular Sequence Data; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sigma Factor
PubMed: 17012583
DOI: 10.1099/ijs.0.64351-0 -
Frontiers in Immunology 2022β-glucan is widely used in aquaculture due to its immunostimulatory effects, but the specific effect and potential regulatory mechanism on largemouth bass () are still...
β-glucan is widely used in aquaculture due to its immunostimulatory effects, but the specific effect and potential regulatory mechanism on largemouth bass () are still unclear. Here, we evaluated the effects of β-glucan on growth, resistance to , intestinal health, and transcriptome of largemouth bass to reveal the potential regulators, metabolic pathways, and altered differential microbiota. Four experimental diets were designed with β-glucan supplementation levels of 0 (control), 100 (LA-100), 200 (MA-200), and 300 (HA-300) mg kg, and each diet was fed to largemouth bass (79.30 ± 0.50 g) in triplicate for 70 days, followed by a 3-day challenge experiment. Results showed that different β-glucan supplementations had no significant effects on growth performance and whole-body composition. Fish fed a diet with 300 mg kg β-glucan significantly increased the activity of lysozyme than those fed diets with 0 and 100 mg kg β-glucan. In addition, the survival rate of largemouth bass in β-glucan supplementation groups was significantly higher than the control group at 12- and 24-h challenge by . Transcriptome analysis showed that a total of 1,245 genes were differentially expressed [|log(fold change)| ≥1, -value ≤0.05], including 109 immune-related differentially expressed genes (DEGs). Further analysis revealed that significantly upregulated and downregulated DEGs associated with immunity were mapped into 12 and 24 pathways, respectively. Results of intestinal microflora indicated that fish fed a diet with 300 mg kg β-glucan had higher bacterial richness and diversity as evaluated by Sobs, Chao, Ace, and Simpson indices, but no significant differences were found in the comparison groups. Furthermore, 300 mg kg β-glucan significantly increased the relative abundance of and decreased (mainly and ) and in largemouth bass intestinal microflora. The findings of this study provided new insights that will be valuable in future studies to elucidate the mechanism of immunity enhancement by β-glucan.
Topics: Animals; Transcriptome; Bass; Diet; Gene Expression Profiling
PubMed: 36591266
DOI: 10.3389/fimmu.2022.1086103 -
Food Microbiology May 2015We aimed to document the risk of Aeromonas spp. in marine shrimp species cultured in inland low salinity ponds in Thailand. In 14 of 18 shrimp samples retrieved from...
We aimed to document the risk of Aeromonas spp. in marine shrimp species cultured in inland low salinity ponds in Thailand. In 14 of 18 shrimp samples retrieved from inland grow-up ponds, Aeromonas spp. were detected at ranges from 4667 to 1,500,000 CFU/g body weight. The phylogenetic tree constructed with the gyrB and cpn60 concatenated sequences indicated that the 87 isolates consisted of Aeromonas veronii (70%), Aeromonas aquariorum (18%), Aeromonas caviae (7%), Aeromonas jandaei (2%), and Aeromonas schubertii (2%). The potential virulence of the isolates was examined by phenotypic and PCR assays. Hemolytic activity and the extracellular activity of lipase, DNase, and gelatinase were observed in most isolates (94-99%). PCR revealed the presence of 9 genes related to virulence in the 87 isolates: act (75%), aer (74%), alt (30%), ast (1%), ascV (34%), aexT (24%), fla (92%), ela (34%), and lip (24%). The susceptibility profiles to 14 antimicrobial agents of isolates were typical for the genus, but resistance to cefotaxime, a third-generation cephalosporin, and imipenem were found in two A. aquariorum and in three A. veronii isolates, respectively. These resistances were confirmed by determining minimum inhibitory concentrations. Our results indicate that the microbiological risk posed by Aeromonas should be considered for marine shrimp species that are cultured in low-salinity ponds. These shrimps may also be a vehicle for the transfer of different genotypes of Aeromonas and antibiotic-resistant determinants to regions worldwide through trade.
Topics: Aeromonas; Animals; Anti-Bacterial Agents; Cefotaxime; Deoxyribonucleases; Drug Resistance, Microbial; Gelatinases; Hemolysis; Imipenem; Microbial Sensitivity Tests; Penaeidae; Penicillin Amidase; Phenotype; Phylogeny; Polymerase Chain Reaction; Salinity; Shellfish; Thailand; Virulence
PubMed: 25583334
DOI: 10.1016/j.fm.2014.11.003