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International Journal of Antimicrobial... Apr 2022This study aimed to describe a clinical isolate of Aeromonas jandaei (A. jandaei) in Nepal that harboured four types of genes encoding phosphoethanolamine transferases.
OBJECTIVES
This study aimed to describe a clinical isolate of Aeromonas jandaei (A. jandaei) in Nepal that harboured four types of genes encoding phosphoethanolamine transferases.
METHODS
An isolate of colistin-resistant A. jandaei was obtained from a blood sample of an inpatient in a hospital in Nepal, and its complete genome sequence was determined. Escherichia coli (E. coli) and Aeromonas hydrophila (A. hydrophila) transformants expressing genes encoding novel phosphoethanolamine transferase variants were constructed and colistin-susceptibility profiles were determined.
RESULTS
The isolate harboured four genes encoding phosphoethanolamine transferases on the chromosome, which were designated eptAv3.2, eptAv3.3, eptAv3.4 and eptAv7.2. The amino acid sequences of EptAv3.2, 3.3 and 3.4 were > 80% identical to MCR-3.1, and that of EptAv7.2 was > 79% identical to MCR-7.1. E. coli expressing eptAv3.2, 3.3 and 3.4 showed reduced susceptibility to colistin, whereas E. coli expressing eptAv7.2 did not. In contrast, A. hydrophila expressing eptAv7.2 showed reduced susceptibility to colistin, whereas A. hydrophila expressing eptAv3.2, 3.3 and 3.4 did not; eptAv3.3 and 3.4 formed a tandem structure. The genomic environments surrounding eptAv3.2, 3.3 and 3.4 were similar to Aeromonas veronii obtained from the effluent of a treatment plant in Japan in 2018. The genomic environment surrounding eptAv7.2 was similar to that of A. jandaei obtained from a chicken in the USA in 2019.
CONCLUSIONS
The highly colistin-resistant A. jandaei clinical isolate harboured four chromosomal genes encoding phosphoethanolamine transferases, suggesting that Aeromonas spp. harbouring eptAv genes with strong similarities to mcr-3 and mcr-7 are emerging in medical settings as well as environments.
Topics: Aeromonas; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Escherichia coli; Escherichia coli Proteins; Ethanolaminephosphotransferase; Ethanolamines; Microbial Sensitivity Tests; Nepal; Plasmids
PubMed: 35134503
DOI: 10.1016/j.ijantimicag.2022.106544 -
Access Microbiology 2023Necrotizing soft tissue infections (NSTIs) are associated with a fulminating course because of their rapid destruction of tissue planes underlying the skin. -associated...
INTRODUCTION
Necrotizing soft tissue infections (NSTIs) are associated with a fulminating course because of their rapid destruction of tissue planes underlying the skin. -associated monomicrobial NSTIs are usually associated with exposure to fresh water, particularly among agricultural workers and fish handlers. Albeit uncommon in incidence, urgent medical and surgical intervention are required once a diagnosis has been made.
CASE REPORT
A 40-year-old male patient, a known case of alcoholic liver disease, presented to the emergency department with pain and diffuse swelling of bilateral lower limbs, which quickly progressed to form blackish discolouration and blebs. Blood for preliminary haematological and biochemical investigations, as well as fluid draining from blebs, were sent for microbiological investigation. The Gram stain revealed occasional neutrophils and Gram-negative bacilli, and pure growth in aerobic culture was identified as by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The patient was started on empirical antimicrobials, although lesions continued to progress and he ultimately succumbed within 12 h of hospital admission.
CONCLUSION
As appropriate antimicrobial therapy and early surgical intervention are required for management of the same, occupational exposure and the fulminant course should raise suspicion of -associated infections.
PubMed: 37970078
DOI: 10.1099/acmi.0.000636.v4 -
Juntendo Iji Zasshi = Juntendo Medical... 2023species are Gram-negative rods known to cause infections such as gastroenteritis, bacteremia and wound infections. Colistin is one of few treatments for...
species are Gram-negative rods known to cause infections such as gastroenteritis, bacteremia and wound infections. Colistin is one of few treatments for multidrug-resistant Gram-negative bacteria. However, colistin-resistant bacteria carrying the mobilized colistin resistance () gene are a threat in healthcare settings worldwide. In recent years, colistin-resistant species have been detected in environmental and clinical samples. We analyzed the genomic characteristics of one highly colistin-resistant isolated from a blood sample in Nepal, which harbored four novel genes on its chromosome. Our study strongly suggests that is a reservoir of colistin-resistant genes. Inappropriate use of drugs in medicine and food production should be reduced and continued global surveillance for colistin-resistant bacteria is necessary.
PubMed: 38855938
DOI: 10.14789/jmj.JMJ22-0047-R -
Frontiers in Microbiology 2021The prevalence of -positive bacteria in 5,169 domestic animal-derived samples collected by USDA Food Safety and Inspection Service between October 2018 and May 2019 was...
The prevalence of -positive bacteria in 5,169 domestic animal-derived samples collected by USDA Food Safety and Inspection Service between October 2018 and May 2019 was investigated. A procedure including enriched broth culture and real-time PCR targeting to were used for the screening. Fifteen positive isolates were identified, including one plasmid-borne -positive strain, EC2492 (reported elsewhere) and 14 -positive strains from poultry (1), catfish (2), and chicken rinse (11) samples, resulting in an overall prevalence of -positive bacteria 0.29% in all meat samples tested. Analysis of 16S rRNA and whole genome sequences revealed that all 14 strains belonged to . Data from phylogenetic analysis of seven housekeeping genes, including , and , indicated that nine strains belonged to and five strains belonged to . Antimicrobial tests showed that almost all -positive strains exhibited high resistance to colistin with MICs ≥ 128mg/L, except for one strain, which showed a borderline resistance with a MIC of 2 mg/L. A segment containing two adjacent and lik genes was found in two and one strains and a variety of IS-like elements were found in the flanking regions of this segment. A -related lipid A phosphoethanolamine transferase gene was present in all 14 strains, while an additional -related lipid A phosphoethanolamine transferase gene was found in 5 strains only. In addition to genes, other antimicrobial resistance genes, including , , , , , , , , and were observed in chromosomes of some strains. The relative high prevalence of chromosome-borne genes and the close proximity of various IS elements to these genes highlights the need for continued vigilance to reduce the mobility of these colistin-resistance genes among food animals.
PubMed: 33995332
DOI: 10.3389/fmicb.2021.667406 -
Microorganisms Oct 2021The aims of this study were to characterize and investigate antimicrobial susceptibility and presence of integrons in 161 spp. isolated from ornamental freshwater fish...
Characterization and Antimicrobial Resistance of Environmental and Clinical Species Isolated from Fresh Water Ornamental Fish and Associated Farming Environment in Sri Lanka.
The aims of this study were to characterize and investigate antimicrobial susceptibility and presence of integrons in 161 spp. isolated from ornamental freshwater fish farming environment, apparently healthy and diseased fish. Phylogenetic analyses of the gene sequences identified as the most abundant species (75.8%) followed by (9.3%), (5%), (4.3%), (3.7%), (0.6%), (0.6%), and (0.6%). Susceptibility to thirteen antimicrobials was determined and antimicrobial resistance frequencies were: amoxicillin (92.5%), enrofloxacin (67.1%), nalidixic acid (63.4%), erythromycin (26.1%), tetracycline (23.6%), imipenem (18%), trimethoprim-sulfamethoxazole (16.8%), and gentamicin (16.8%). Multi-drug resistance (MDR) was widespread among the isolates (51.6%, 83/161) with 51.6% (63/122) isolates being MDR. In addition, 68.3% of isolates had multiple antibiotic resistance (MAR) indexes higher than 0.2, suggesting that they originated from a high-risk source of contamination where antimicrobials are often used. In all, 21.7% isolates carried class 1 integrons, with 97.1% having gene cassettes, while there were 12 isolates carrying class 2 integron gene cassettes. Our findings highlight that the aquatic environment and ornamental fish act as reservoirs of multidrug resistant spp. and underline the need for a judicious use of antimicrobials and timely surveillance of antimicrobial resistance (AMR) in aquaculture.
PubMed: 34683427
DOI: 10.3390/microorganisms9102106 -
Journal of Agricultural and Food... Nov 2023Lactic acid bacteria (LAB) were screened from (red sea bass), and their antimicrobial activities were evaluated against two species isolated from the , namely, (AV)...
Lactic acid bacteria (LAB) were screened from (red sea bass), and their antimicrobial activities were evaluated against two species isolated from the , namely, (AV) and (AJ). Three LAB isolates, MU8 (EF_8), MU2 (EFL_2), and MU9 (EFL_9), were found to inhibit both AV and AJ; however, their cell-free supernatant (CFS) did not do so. Interestingly, bacteriocin-like substances (BLS) induced by cocultures of EF_8 with AV exhibited the highest antimicrobial activity against both sp. The size of BLS was less than 1.0 kDa; the purified BLS were susceptible to proteinase K digestion, indicating that they are peptides. BLS contained 13 identified peptides derived from as determined by liquid chromatography-tandem mass spectrometry. Cocultures of Gram-positive-producing and -inducing LAB strains have been used to increase bacteriocin yields. To our knowledge, this is the first report describing inducible BLS produced by cocultures of Gram-positive-producing and Gram-negative-inducing strains.
Topics: Enterococcus faecium; Bacteriocins; Aeromonas veronii; Coculture Techniques; Aeromonas; Peptides; Anti-Infective Agents; Anti-Bacterial Agents
PubMed: 37779478
DOI: 10.1021/acs.jafc.3c04019 -
Frontiers in Immunology 2022are autochthonous bacteria of aquatic environments that are considered to be emerging pathogens to humans, producing diarrhea, bacteremia, and wound infections. Genetic...
are autochthonous bacteria of aquatic environments that are considered to be emerging pathogens to humans, producing diarrhea, bacteremia, and wound infections. Genetic identification shows that 95.4% of the strains associated with clinical cases correspond to the species (37.26%), (23.49%), (21.54%), and (13.07%). However, few studies have investigated the human immune response against some spp. such as , , and . The present study aimed to increase the knowledge about the innate human immune response against six species, using, for the first time, an infection model with the monocytic human cell line THP-1, and to evaluate the intracellular survival, the cell damage, and the expression of 11 immune-related genes (, , , , , , , , , , and ). Transcriptional analysis showed an upregulated expression of a variety of the monocytic immune-related genes, with a variable response depending upon the species. The species that produced the highest cell damage, independently of the strain origin, coincidentally induced a higher expression of immune-related genes and corresponded to the more prevalent clinical species , , and . Additionally, monocytic cells showed an overexpression of the apoptotic and pyroptotic genes involved in cell death after , , and infection. However, the apoptosis route seemed to be the only way of producing cell damage and death in the case of the species and , while apparently only used the pyroptosis route.
Topics: Aeromonas; Aeromonas hydrophila; Cell Line; Gram-Negative Bacterial Infections; Humans; Immunity
PubMed: 35874671
DOI: 10.3389/fimmu.2022.875689 -
Antimicrobial Resistance and Infection... Feb 2021The study aimed to elucidate the species taxonomy, clinical manifestations, virulence gene profiles and antimicrobial susceptibilities of Aeromonas strains isolated from...
BACKGROUND
The study aimed to elucidate the species taxonomy, clinical manifestations, virulence gene profiles and antimicrobial susceptibilities of Aeromonas strains isolated from life-threatening bacteremia in southeastern China.
METHODS
Clinical samples of Aeromonas causing bacteremia were isolated from a teaching hospital in Wenzhou from 2013 to 2018 and a retrospective cohort study was performed. Aeromonas strains were identified at species level by housekeeping gene gyrB. Virulence and drug resistance-associated genes were screened by polymerase chain reaction (PCR) and antimicrobial susceptibility testing (AST) was performed by the VITEK 2 Compact system.
RESULTS
A total of 58 Aeromonas isolated from patients with bacteremia were collected during 6 years (2013-2018). 58 isolates were identified to five different species, where Aeromonas dhakensis appeared to be the predominant species (26/58), followed by Aeromonas veronii (13/58), Aeromonas caviae (10/58), Aeromonas hydrophila (7/58) and Aeromonas jandaei (2/58). 16 of 58 patients had poor prognosis. Poor prognosis was significantly associated with liver cirrhosis and inappropriate empirical antimicrobials therapy. The progression of bacteremia caused by Aeromonas was extremely fast, especially in A. dhakensis infections. Virulence genes aer, lip, hlyA, alt, ast, and act, were detected at ratios of 24.1% (14/58), 62.1% (36/58), 65.5% (38/58), 58.6% (34/58), 15.5% (9/58) and 65.5% (38/58), respectively. Antimicrobial susceptibility testing exhibited that 9 out of 58 isolates were identified as multi-drug resistant (MDR) organism. The bla gene was identified in all 9 MDR isolates. bla, bla, bla, bla, bla and aac(6')-Ib-cr were detected in 4 isolates, 2 isolates, 1 isolate, 3 isolates, 8 isolates, and 3 isolates, respectively. The majority of Aeromonas strains maintained susceptible to 3rd generation cephalosporins, aminoglycosides, fluoroquinolones and furantoin.
CONCLUSIONS
The prevalence and dangerousness of Aeromonas infections, especially A. dhakensis, are underestimated in clinic. Continuous monitoring is essential to keep track of MDR Aeromonas due to the increasing prevalence recently and a more effective measure is required to control the spread of resistance determinants.
Topics: Adult; Aeromonas; Aged; Anti-Bacterial Agents; Bacteremia; China; Female; Gram-Negative Bacterial Infections; Hospitals, Teaching; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Phylogeny; Retrospective Studies; Virulence; Virulence Factors
PubMed: 33640019
DOI: 10.1186/s13756-021-00911-0 -
Scientific Reports Mar 2021Diseased Anabas testudineus exhibiting signs of tail-rot and ulcerations on body were collected from a fish farm in Assam, India during the winter season (November 2018...
Diseased Anabas testudineus exhibiting signs of tail-rot and ulcerations on body were collected from a fish farm in Assam, India during the winter season (November 2018 to January 2019). Swabs from the infected body parts were streaked on sterilized nutrient agar. Two dominant bacterial colonies were obtained, which were then isolated and labelled as AM-31 and AM-05. Standard biochemical characterisation and 16S rRNA and rpoB gene sequencing identified AM-31 isolate as Aeromonas hydrophila and AM-05 as Aeromonas jandaei. Symptoms similar to that of natural infection were observed on re-infecting both bacteria to disease-free A. testudineus, which confirmed their virulence. LC was determined at 1.3 × 10 (A. hydrophila) and 2.5 × 10 (A. jandaei) CFU per fish in intraperitoneal injection. Further, PCR amplification of specific genes responsible for virulence (aerolysin and enterotoxin) confirmed pathogenicity of both bacteria. Histopathology of kidney and liver in the experimentally-infected fishes revealed haemorrhage, tubular degeneration and vacuolation. Antibiotic profiles were also assessed for both bacteria. To the best of our knowledge, the present work is a first report on the mortality of farmed climbing perch naturally-infected by A. hydrophila as well as A. jandaei, with no records of pathogenicity of the latter in this fish.
Topics: Aeromonas; Aeromonas hydrophila; Animals; Fish Diseases; Gram-Negative Bacterial Infections; Hemorrhagic Septicemia; Perches
PubMed: 33712685
DOI: 10.1038/s41598-021-84997-x -
Veterinary World Aug 2021The emergence of antibiotic-resistant bacterial pathogens has been increasingly reported, which has resulted in a decreasing ability to treat bacterial infections....
BACKGROUND AND AIM
The emergence of antibiotic-resistant bacterial pathogens has been increasingly reported, which has resulted in a decreasing ability to treat bacterial infections. Therefore, this study investigated the presence of spp., including its antibiotic resistance in various fish samples, spp., , and , obtained from Kelantan and Terengganu, Malaysia.
MATERIALS AND METHODS
In this study, 221 fish samples, of which 108 ( spp., n=38; , n=35; and , n=35) were from Kelantan and 113 ( spp., n=38; , n=35; and , n=40) were from Terengganu, were caught using cast nets. Then, samples from their kidneys were cultured on a Rimler Shott agar to isolate spp. Polymerase chain reaction (PCR) was used to confirm this isolation using specific gene primers for species identification. Subsequently, the isolates were tested for their sensitivity to 14 antibiotics using the Kirby-Bauer method, after which the PCR was conducted again to detect resistance genes: , -, , , , -, and .
RESULTS
From the results, 61 isolates were identified as being from the genus using PCR, of which 28 were , 19 were , seven were , and seven were . Moreover, 8, 12, and 8 of ; 4, 3, and 12 of ; 6, 0, and 1 of ; and 3, 3, and 1 of were obtained from spp., , and , respectively. In addition, the isolates showed the highest level of resistance to ampicillin (100%), followed by streptomycin (59.0%), each kanamycin and nalidixic acid (41.0%), neomycin (36.1%), tetracycline (19.7%), sulfamethoxazole (14.8%), and oxytetracycline (13.1%). Resistance to gentamicin and ciprofloxacin both had the same percentage (9.8%), whereas isolates showed the lowest resistance to norfloxacin (8.2%) and doxycycline (1.6%). Notably, all isolates were susceptible to chloramphenicol and nitrofurantoin. Results also revealed that the multiple antibiotic resistances index of the isolates ranged from 0.07 to 0.64, suggesting that the farmed fish in these areas were introduced to the logged antibiotics indiscriminately and constantly during their cultivation stages. Results also revealed that the gene was detected in 19.7% of the isolates, whereas the tetracycline resistance genes, and , were detected in 27.9% and 4.9% of the isolates, respectively. However, β-lactam resistance genes, and , were found in 44.3% and 13.1% of isolates, respectively, whereas and genes were found in 3.3% and 13.1% of the isolates, respectively.
CONCLUSION
This study, therefore, calls for continuous surveillance of antibiotic-resistant spp. in cultured freshwater fish to aid disease management and better understand their implications to public health.
PubMed: 34566322
DOI: 10.14202/vetworld.2021.2064-2072