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1.
Fish Shellfish Immunol ; 132: 108487, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36503060

RESUMO

The outbreak of mass mortality of M. salmoides occurred in an aquaculture farm in Jiangsu province of China, showing signs of skin ulceration and haemorrhages. The bacteria were isolated from diseased largemouth bass, and identified as Plesiomonas shigelloides based on morphological, physiological and biochemical features, as well as 16S rRNA gene sequence analysis. The pathogenicity of P. shigelloides was determined by challenge experiments, and the median lethal dosage (LD50) of the isolate NJS1 for M. salmoides was calculated as 1.6 × 105 CFU/mL at 7 d post-infection. Histopathological analysis revealed that extensive necrosis, vacuolization and inflammation were presented in the kidney, liver and gill of the diseased fish. Detection of virulence-related genes showed that P. shigelloides NJS1 was positive for astA, astB, astD, astE, actP and 6 ahpA. Additionally, the host defensive response of M. salmoides infected by P. shigelloides was analyzed by quantitive real-time PCR (qRT-PCR), and the results showed that the expression levels of Cas3, Hep1, HIF, IgM, IL15 and TGF were significantly up-regulated in head kidney, liver and spleen in different hours post-infection, which revealed varying expression profiles and clear transcriptional activation of immune related genes. The results suggested that P. shigelloides was an etiological element in the mass mortalities of M. salmoides and this study provided deeper insights for the pathogenesis and host defensive system in P. shigelloides invasion.


Assuntos
Bass , Plesiomonas , Animais , Plesiomonas/genética , Virulência , RNA Ribossômico 16S/genética , Imunidade
2.
BMC Microbiol ; 22(1): 299, 2022 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-36510135

RESUMO

BACKGROUND: RpoN, also known as σ54, first reported in Escherichia coli, is a subunit of RNA polymerase that strictly controls the expression of different genes by identifying specific promoter elements. RpoN has an important regulatory function in carbon and nitrogen metabolism and participates in the regulation of flagellar synthesis, bacterial motility and virulence. However, little is known about the effect of RpoN in Plesiomonas shigelloides. RESULTS: To identify pathways controlled by RpoN, RNA sequencing (RNA-Seq) of the WT and the rpoN deletion strain was carried out for comparison. The RNA-seq results showed that RpoN regulates ~ 13.2% of the P. shigelloides transcriptome, involves amino acid transport and metabolism, glycerophospholipid metabolism, pantothenate and CoA biosynthesis, ribosome biosynthesis, flagellar assembly and bacterial secretion system. Furthermore, we verified the results of RNA-seq using quantitative real-time reverse transcription PCR, which indicated that the absence of rpoN caused downregulation of more than half of the polar and lateral flagella genes in P. shigelloides, and the ΔrpoN mutant was also non-motile and lacked flagella. In the present study, the ability of the ΔrpoN mutant to kill E. coli MG1655 was reduced by 54.6% compared with that of the WT, which was consistent with results in RNA-seq, which showed that the type II secretion system (T2SS-2) genes and the type VI secretion system (T6SS) genes were repressed. By contrast, the expression of type III secretion system genes was largely unchanged in the ΔrpoN mutant transcriptome and the ability of the ΔrpoN mutant to infect Caco-2 cells was also not significantly different compared with the WT. CONCLUSIONS: We showed that RpoN is required for the motility and contributes to the killing ability of P. shigelloides and positively regulates the T6SS and T2SS-2 genes.


Assuntos
Regulação Bacteriana da Expressão Gênica , Plesiomonas , Humanos , RNA Polimerase Sigma 54/genética , Plesiomonas/genética , Plesiomonas/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Células CACO-2
3.
Microb Pathog ; 173(Pt A): 105818, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36216208

RESUMO

Chinese sturgeon (Acipenser sinensis) is an indigenous species of China and is listed as a critically endangered species. Recently, second filial generations of Chinese sturgeon in the Yangtze River Fisheries Research Institute suffered from a severe disease. In this study, two kinds of pathogenic bacteria were isolated from diseased sturgeon and identified as Plesiomonas shigelloides and Citrobacter freundii, based on 16S rDNA gene sequence alignment analysis. Antimicrobial susceptibility testing showed that P. shigelloides was resistant to ampicillin, penicillin, midecamycin, oxacillin, and clindamycin; and sensitive to tocefatriaxone, piperacillin, cefoperazone, cefazolin, and ciprofloxacin. C. freundii was resistant to ampicillin, penicillin, midecamycin, oxacillin, and clindamycin; and sensitive to chloramphenicol, cefuroxime, norfloxacin, ciprofloxacin, and ceftazidime. The median lethal dose (LD50) values of P. shigelloides and C. freundii were 4.50 × 103 colony forming units (CFU)/g and 3.20 × 103 CFU/g, respectively. Clinical symptoms of challenged sturgeons were the same as those of naturally infected sturgeons. Histopathological examination disclosed severe damage in the viscera of P. shigelloides and C. freundii-infected sturgeons. This is the first report suggesting that P. shigelloides infection is associated with mortality of Chinese sturgeon. The results of this study revealed the pathogenesis and severe pathogenicity of P. shigelloides and C. freundii in cultured Chinese sturgeon, and offer insights into the prevention and treatment of bacterial infection caused by P. shigelloides and C. freundii in cultured sturgeons.


Assuntos
Plesiomonas , Animais , Plesiomonas/genética , Citrobacter freundii/genética , Virulência , Clindamicina , Peixes/genética , Oxacilina , Ampicilina , Ciprofloxacina
4.
J Infect Chemother ; 28(12): 1677-1681, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36067910

RESUMO

Plesiomonas shigelloides is a gram-negative facultative anaerobic bacillus, usually found in soil and freshwater, which causes self-limited diarrhea, although reports of bacteremia are rare. Here, we report the first case of an intratumoral abscess with mixed bacteremia caused by P. shigelloides, Citrobacter freundii, Streptococcus mitis/oralis, Clostridium perfringens, and Candida albicans in a patient with recurrent postoperative cholangiocarcinoma. A 77-year-old man with hilar cholangiocarcinoma and hypertension was admitted to our hospital with fever and abdominal pain. He had visited Vietnam for 3 years, 20 years ago. Abdominal computed tomography showed air within the recurrent tumor at the left liver lobectomy resection margin site, which was diagnosed as an intratumor abscess perforating the intestinal tract. P. shigelloides, C. freundii, S. mitis/oralis, C. perfringens, and C. albicans were isolated in blood culture. P. shigelloides was identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and 16S ribosomal RNA (16S rRNA) sequencing. Piperacillin-tazobactam was administered for almost a week, ampicillin-sulbactam and levofloxacin for almost 3 weeks, and antifungal agents for almost 2 weeks, and the patient was discharged thereafter. Although bloodstream infections caused by P. shigelloides in patients with cancer are extremely rare, long-term colonization and the potential for future intra-abdominal infections were implicated.


Assuntos
Bacteriemia , Neoplasias dos Ductos Biliares , Colangiocarcinoma , Plesiomonas , Sepse , Abscesso , Idoso , Antifúngicos , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Ductos Biliares Intra-Hepáticos , Candida albicans , Citrobacter freundii , Clostridium perfringens , Humanos , Levofloxacino , Masculino , Piperacilina , Plesiomonas/química , RNA Ribossômico 16S/genética , Solo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Streptococcus mitis , Streptococcus oralis , Tazobactam
5.
Front Immunol ; 13: 872896, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35844551

RESUMO

Various bacterial diseases have caused great economic losses to the high-density and intensive aquaculture industry; however, the pathogenic mechanism underlying the large-scale challenged to caused by many bacteria remain unclear, making the prevention and treatment of these diseases difficult. In the present study, we isolated a bacterial strain from Cyprinus carpio having a typical bacterial disease and named it Cc2021. Through subsequent morphological observations, a regression challenge, biochemical identification, and 16S rRNA gene sequence analysis, we determined Cc2021 to be Plesiomonas shigelloides. Subsequently, we comprehensively investigated the pathogenicity of P. shigelloides in C. carpio through a regression challenge and assessed the underlying the pathogenic mechanism. Mortality results revealed that P. shigelloides is highly pathogenic and infects various tissues throughout the body, resulting in edema of the liver, spleen, and body and head kidneys. Histopathological analysis revealed obvious inflammation, bleeding, and necrosis in the intestine, spleen, and head kidney. The body's immune tissues actively produce complement C3, superoxide dismutase, and lysozyme after a challenge to resist bacterial invasion. With regard to the underlying pathogenesis of P. shigelloides, comparative transcriptome analysis revealed 876 upregulated genes and 828 downregulated genes in the intestine of C. carpio after the challenge. Analysis of differentially expressed unigenes revealed the involvement of major immune pathways, particularly the TNF signaling pathway, interleukin (IL)-17 signaling pathway, and Toll-like receptor signaling pathway. The present study provides new valuable information on the immune system and defense mechanisms of P. shigelloides.


Assuntos
Carpas , Plesiomonas , Animais , Plesiomonas/genética , RNA Ribossômico 16S/genética , Transcriptoma , Virulência
6.
BMC Vet Res ; 18(1): 137, 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35414073

RESUMO

BACKGROUND: Bacterial infections are responsible of high economic losses in aquaculture. Mexican golden trout (Oncorhynchus chrysogaster) is a threatened native trout species that has been introduced in aquaculture both for species conservation and breeding for production and for which no studies of bacterial infections have been reported. CASE PRESENTATION: Fish from juvenile stages of Mexican golden trout showed an infectious outbreak in a farm in co-culture with rainbow trout (Oncorhynchus mykiss), showing external puntiform red lesions around the mouth and caudal pedunculus resembling furuncles by Aeromonas spp. and causing an accumulated mortality of 91%. Isolation and molecular identification of bacteria from lesions and internal organs showed the presence of Aeromonas bestiarum, Aeromonas sobria, Plesiomonas shigelloides and Ichthyobodo necator isolated from a single individual. All bacterial isolates were resistant to amoxicillin-clavulanic acid and cefazoline. P. shigelloides was resistant to third generation ß-lactamics. CONCLUSIONS: This is the first report of coinfection by Aeromonas bestiarum, Aeromonas sobria, Plesiomonas shigelloides and Ichthyobodo necator in an individual of Mexican golden trout in co-culture with rainbow trout. Resistance to ß-lactams suggests the acquisition of genetic determinants from water contamination by human- or livestock-associated activities.


Assuntos
Aeromonas , Coinfecção , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Oncorhynchus mykiss , Oncorhynchus , Parasitos , Plesiomonas , Aeromonas/genética , Animais , Coinfecção/veterinária , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Necator , Plesiomonas/genética
7.
Jpn J Infect Dis ; 75(4): 407-410, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35095023

RESUMO

The genus Plesiomonas, represented by a single species, Plesiomonas shigelloides, is a gram-negative bacillus associated with gastrointestinal and extraintestinal diseases in humans. In this study, 44 clinical isolates (gastrointestinal, n = 41; extraintestinal, n = 3) were genetically confirmed to be P. shigelloides using the hug gene. All 20 virulence genes were detected in the gastrointestinal isolates, ranging from 7.7% to 100%; however, only 12 genes were detected in the extra-gastrointestinal isolates, ranging from 33.3% to 100%. The phlA gene was significantly associated with the gastrointestinal isolates (P = 0.0216). The results of this study suggest that phlA may play a role in gastrointestinal infections. However, pilF, tolC, and fur were detected in both gastrointestinal and extraintestinal clinical isolates, and further investigations are warranted to elucidate their role in the pathogenesis of P. shigelloides.


Assuntos
Infecções por Bactérias Gram-Negativas , Plesiomonas , Humanos , Plesiomonas/genética , Virulência/genética
8.
Genome Biol Evol ; 14(2)2022 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-35078241

RESUMO

About 10% of bacteria have a multichromosome genome with a primary replicon of bacterial origin, called the chromosome, and other replicons of plasmid origin, the chromids. Studies on multichromosome bacteria revealed potential points of coordination between the replication/segregation of chromids and the progression of the cell cycle. For example, replication of the chromid of Vibrionales (called Chr2) is initiated upon duplication of a sequence carried by the primary chromosome (called Chr1), in such a way that replication of both replicons is completed synchronously. Also, Chr2 uses the Chr1 as a scaffold for its partition in the daughter cells. How many of the features detected so far are required for the proper integration of a secondary chromosome in the cell cycle? How many more features remain to be discovered? We hypothesized that critical features for the integration of the replication/segregation of a given chromid within the cell cycle program would be conserved independently of the species in which the chromid has settled. Hence, we searched for a chromid related to that found in Vibrionales outside of this order. We identified one in Plesiomonas shigelloides, an aquatic and pathogenic enterobacterium that diverged early within the clade of Enterobacterales. Our results suggest that the chromids present in P. shigelloides and Vibrionales derive from a common ancestor. We initiated in silico genomic and proteomic comparative analyses of P. shigelloides, Vibrionales, and Enterobacterales that enabled us to establish a list of features likely involved in the maintenance of the chromid within the host cell cycle.


Assuntos
Plesiomonas , Vibrio , Cromossomos Bacterianos/genética , Genoma Bacteriano , Plesiomonas/genética , Proteômica , Vibrio/genética
9.
J Med Case Rep ; 16(1): 53, 2022 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-35086562

RESUMO

BACKGROUND: The detection of epidemic-prone pathogens is important in strengthening global health security. Effective public health laboratories are critical for reliable, accurate, and timely testing results in outbreak situations. Ghana received funding as one of the high-risk non-Ebola affected countries to build and strengthen public health infrastructure to meet International Health Regulation core capacities. A key objective was to build laboratory capacities to detect epidemic-prone diseases. CASE PRESENTATION: In June 2018, a local hospital received eight patients who presented with acute diarrhea. A sample referral system for Ghana has not been established, but the Sekondi Zonal Public Health Laboratory staff and mentors collaborated with Disease Surveillance Officers (DSOs) to collect, package, and transport stool specimens from the outbreak hospital to the Public Health Laboratory for laboratory testing. The patients included seven females and one male, of Fante ethnicity from the Fijai township of Sekondi-Takoradi Municipality. The median age of the patients was 20 years (interquartile range: 20-29 years). Vibrio parahaemolyticus was identified within 48 hours from four patients, Plesiomonas shigelloides from one patient, and Aeromonas hydrophila from another patient. There was no bacteria growth from the samples from the two other patients. All patients were successfully treated and discharged. CONCLUSION: This is the first time these isolates have been identified at the Sekondi Zonal Public Health Laboratory, demonstrating how rapid response, specimen transportation, laboratory resourcing, and public health coordination are important in building capacity towards achieving health security. This capacity building was part of the United States Centers for Disease Control and Prevention engagement of international and local partners to support public health laboratories with supplies, diagnostic equipment, reagents, and logistics.


Assuntos
Aeromonas , Plesiomonas , Vibrio parahaemolyticus , Adulto , Aeromonas hydrophila , Surtos de Doenças , Gana/epidemiologia , Humanos , Laboratórios , Masculino , Adulto Jovem
10.
Org Lett ; 23(15): 6137-6142, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34291950

RESUMO

First total synthesis of the conjugation-ready pentasaccharide repeating unit of Plesiomonas shigelloides strain 302-73 (serotype O1) is reported. The complex target pentasaccharide is composed of all-rare amino sugars such as orthogonally functionalized d-bacillosamine, l-fucosamine, and l-pneumosamine linked through four consecutive α-linkages. The poor nucleophilicity of axial 4-OH of l-fucosamine and stereoselective glycosylations are the key challenges in the total synthesis, which was completed via a longest linear sequence of 27 steps in 3% overall yield.


Assuntos
Amino Açúcares/síntese química , Oligossacarídeos/síntese química , Plesiomonas/química , Amino Açúcares/química , Estrutura Molecular , Oligossacarídeos/química , Sorogrupo
11.
J Microbiol Biotechnol ; 31(4): 520-528, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33746188

RESUMO

Plesiomonas shigelloides, a member of the family Vibrionaceae, is a gram-negative, rod-shaped, facultative anaerobic bacterium with flagella. P. shigelloides has been isolated from such sources as freshwater, surface water, and many wild and domestic animals. P. shigelloides contains 102 Oantigens and 51 H-antigens. The diversity of O-antigen gene clusters is relatively poorly understood. In addition to O1 and O17 reported by other laboratories, and the 12 O serogroups (O2, O10, O12, O23, O25, O26, O32, O33, O34, O66, O75, and O76) reported previously by us, in the present study, nine new P. shigelloides serogroups (O8, O17, O18, O37, O38, O39, O44, O45, and O61) were sequenced and annotated. The genes for the O-antigens of these nine groups are clustered together in the chromosome between rep and aqpZ. Only O38 possesses the wzm and wzt genes for the synthesis and translocation of O-antigens via the ATP-binding cassette (ABC) transporter pathway; the other eight use the Wzx/Wzy pathway. Phylogenetic analysis using wzx and wzy showed that both genes are diversified. Among the nine new P. shigelloides serogroups, eight use wzx/wzy genes as targets. In addition, we developed an O-antigen-specific PCR assay to detect these nine distinct serogroups with no cross reactions among them.


Assuntos
Família Multigênica , Antígenos O/genética , Plesiomonas/classificação , Sorotipagem , Filogenia , Plesiomonas/genética , Reação em Cadeia da Polimerase , Análise de Sequência de DNA
12.
Protein Expr Purif ; 183: 105859, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33647399

RESUMO

Methyl parathion hydrolase (MPH) hydrolyses methyl parathion efficiently and specifically. Herein, we produced MPH from Plesiomonas sp. M6 using a Pichia pastoris multi-copy expression system. The original signal peptide sequence of the target gene was removed, and a modified coding sequence was synthesised. Multi-copy expression plasmids containing MPH were constructed using pHBM905BDM, and used to generate recombinant strains containing 1, 2, 3 or 4 copies of the MPH gene. The results showed that a higher target gene copy number increased the production of recombinant MPH (MPH-R), as anticipated. The expression level of the recombinant strain containing four copies of the MPH gene was increased to 1.9 U/ml using 500 ml shake flasks, and the specific activity was 15.8 U/mg. High-density fermentation further increased the target protein yield to 18.4 U/ml. Several metal ions were tested as additives, and Ni2+, Co2+ and Mg2+ at a concentration of 1 mM enhanced MPH-R activity by 196%, 201% and 154%, respectively. Enzyme immobilisation was then applied to overcome the difficulties in recovery, recycling and long-term stability associated with the free enzyme. Immobilised MPH-R exhibited significantly enhanced thermal and long-term stability, as well as broad pH adaptability. In the presence of inhibitors and chelating agents such as sodium dodecyl sulphate (SDS), immobilised MPH-R displayed 2-fold higher activity than free MPH-R, demonstrating its potential for industrial application.


Assuntos
Proteínas de Bactérias , Enzimas Imobilizadas , Expressão Gênica , Monoéster Fosfórico Hidrolases , Plesiomonas/genética , Saccharomycetales , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Enzimas Imobilizadas/biossíntese , Enzimas Imobilizadas/química , Enzimas Imobilizadas/genética , Enzimas Imobilizadas/isolamento & purificação , Monoéster Fosfórico Hidrolases/biossíntese , Monoéster Fosfórico Hidrolases/química , Monoéster Fosfórico Hidrolases/genética , Monoéster Fosfórico Hidrolases/isolamento & purificação , Plesiomonas/enzimologia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Saccharomycetales/genética , Saccharomycetales/metabolismo
13.
Virus Res ; 306: 198581, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34560184

RESUMO

Plesiomonas shigelloides is an important fish pathogen that causes significant losses in aquaculture. Phage therapy is a new approach to overcome the problem of multidrug-resistant bacteria. Herein, a virulent phage of P. shigelloides was isolated from the intestines of grass carp. This phage belongs to the Siphoviridae family and was designated PSP01. The optimal multiplicity of infection of PSP01 was 1 with a latent period of 30 min and a lytic period of 140 min. Good activity was observed over a wide range of temperatures (-20 °C-50 °C), pH values (3-12), and NaCl concentrations (0.1-3.5%). The phage PSP01 lysis cassette is composed of 3 genes, HolPSP, LysPSP-1 and LysPSP-2. Expression of HolPSP or LysPSP-2 in Escherichia coli resulted in bacterial lysis, and a synergistic effect was observed when the HolPSP and LysPSP-1 proteins were co-expressed. In-frame deletion uncovered an important role of the transmembrane domain (TMD) in HolPSP and the signal peptide (SP) in LysPSP-2 for bacterial lysis function. The protective effects of phage PSP01 were investigated by intraperitoneal injection into grass carp infected with P. shigelloides, showing a 33.3% increase in the survival rate of the infected grass carp. Pathological analysis of the spleens from the infected grass carp revealed alleviation of the pathological symptoms. In conclusion, isolation and bacterial lysis investigations of phage PSP01 provide a new tool for the control of fish pathogens and possesses potential for aquaculture applications.


Assuntos
Bacteriófagos , Carpas , Plesiomonas , Animais , Aquicultura , Bacteriófagos/genética , Escherichia coli , Plesiomonas/genética
14.
ScientificWorldJournal ; 2021: 3119958, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34594160

RESUMO

Fish and fish products are considered a fundamental part of the human diet due to their high nutritional value. Food-borne diseases are considered a major public health challenge worldwide due to their incidence, associated mortality, and negative economic repercussions. Food safety is the guarantee that foods will not cause harm to the health of those who consume them, and it is a fundamental property of food quality. Food safety can be at risk of being lost at any stage of the food chain if the food is contaminated by pathogenic microorganisms. Many diverse bacteria are present in the environment and as part of the microbiota of food that can be transmitted to humans during the handling and consumption of food. Plesiomonas shigelloides has been mainly associated with outbreaks of gastrointestinal diseases due to the consumption of fish. This bacterium inhabits the environment and aquatic animals and is associated with the microbiota of fish such as tilapia, a fish of importance in fishing, aquaculture, commercialization, and consumption worldwide. The purpose of this document is to provide, through a bibliographic review of databases (Scopus, Web of Science, and Google Scholar, among others), a general informative perspective on food-borne diseases and, in particular, the consumption of fish and tilapia. Diseases derived from contamination by Plesiomonas shigelloides are included, and control and prevention actions and sanitary regulations for fishery products established in several countries around the world are discussed to promote the safety of foods of aquatic origin intended for human consumption and to protect public health.


Assuntos
Doenças dos Peixes/microbiologia , Contaminação de Alimentos , Microbiologia de Alimentos , Gastroenterite/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Plesiomonas/isolamento & purificação , Alimentos Marinhos/microbiologia , Tilápia/microbiologia , Animais , Aquicultura , Carga Bacteriana , Criopreservação , Reservatórios de Doenças , Produtos Pesqueiros/microbiologia , Manipulação de Alimentos , Conservação de Alimentos , Inocuidade dos Alimentos , Gastroenterite/epidemiologia , Gastroenterite/etiologia , Gastroenterite/prevenção & controle , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Plesiomonas/crescimento & desenvolvimento , Prevalência , Controle de Qualidade , Poluição da Água
15.
BMC Microbiol ; 21(1): 266, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34607564

RESUMO

BACKGROUND: The anoxic redox control binary system plays an important role in the response to oxygen as a signal in the environment. In particular, phosphorylated ArcA, as a global transcription factor, binds to the promoter regions of its target genes to regulate the expression of aerobic and anaerobic metabolism genes. However, the function of ArcA in Plesiomonas shigelloides is unknown. RESULTS: In the present study, P. shigelloides was used as the research object. The differences in growth, motility, biofilm formation, and virulence between the WT strain and the ΔarcA isogenic deletion mutant strain were compared. The data showed that the absence of arcA not only caused growth retardation of P. shigelloides in the log phase, but also greatly reduced the glucose utilization in M9 medium before the stationary phase. The motility of the ΔarcA mutant strain was either greatly reduced when grown in swim agar, or basically lost when grown in swarm agar. The electrophoretic mobility shift assay results showed that ArcA bound to the promoter regions of the flaK, rpoN, and cheV genes, indicating that ArcA directly regulates the expression of these three motility-related genes in P. shigelloides. Meanwhile, the ability of the ΔarcA strain to infect Caco-2 cells was reduced by 40%; on the contrary, its biofilm formation was enhanced. Furthermore, the complementation of the WT arcA gene from pBAD33-arcA+ was constructed and all of the above features of the pBAD33-arcA+ complemented strain were restored to the WT level. CONCLUSIONS: We showed the effect of ArcA on the growth, motility, biofilm formation, and virulence of Plesiomonas shigelloides, and demonstrated that ArcA functions as a positive regulator controls the motility of P. shigelloides by directly regulating the expression of flaK, rpoN and cheV genes.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes , Plesiomonas/genética , Plesiomonas/patogenicidade , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Virulência/genética
16.
Mol Cell Probes ; 55: 101689, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33338586

RESUMO

A multiplex PCR (mPCR) assay was established to detect five pathogenic Vibrio species and Plesiomonas shigelloides. Twelve genes were included: ompW, ctxA, rfbN, and wbfR from V. cholerae; tl, tdh, and trh from V. parahaemolyticus; toxR and vmhA from V. mimicus; toxR from V. fluvialis; vvhA from V. vulnificus; and the 23S rRNA gene from P. shigelloides. The specificity of the mPCR assay was 100% for the detection of 136 strains and the limits of detection (LoD) were 12.5-50 pg/reaction. The assay exhibited higher sensitivity than cultivation methods in the detection of APW cultures of 113 diarrhea samples. In the analysis of 369 suspected Vibrio populations from estuarine water samples, the specificity of the mPCR for V. cholerae and V. parahaemolyticus was 100% for both, while the sensitivities were 100% and 96.1%, respectively. The assay can be applied to screen enrichment cultures and suspected colonies from environmental and clinical samples.


Assuntos
Reação em Cadeia da Polimerase Multiplex/métodos , Plesiomonas/genética , Plesiomonas/isolamento & purificação , Vibrio/genética , Vibrio/isolamento & purificação , Eletroforese Capilar , Estuários , Humanos , Sensibilidade e Especificidade , Microbiologia da Água
17.
Int J Mol Sci ; 21(18)2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32947917

RESUMO

Plesiomonas shigelloides is a Gram-negative, rod-shaped bacterium which causes foodborne intestinal infections, including gastroenteritis. It is one of the most frequent causes of travellers' diarrhoea. Lipopolysaccharide (LPS, endotoxin), an important virulence factor of the species, is in most cases characterised by a smooth character, demonstrated by the presence of all regions, such as lipid A, core oligosaccharide, and O-specific polysaccharide, where the latter part determines O-serotype. P. shigelloides LPS is still a poorly characterised virulence factor considering a "translation" of the particular O-serotype into chemical structure. To date, LPS structure has only been elucidated for 15 strains out of 102 O-serotypes. Structures of the new O-specific polysaccharide and core oligosaccharide of P. shigelloides from the Czechoslovak National Collection of Type Cultures CNCTC 90/89 LPS (O22), investigated by chemical analysis, mass spectrometry, and 1H,13C nuclear magnetic resonance (NMR) spectroscopy, have now been reported. The pentasaccharide repeating unit of the O-specific polysaccharide is built of one d-QuipNAc and is rich in four d-GalpNAcAN residues. Moreover, the new core oligosaccharide shares common features of other P. shigelloides endotoxins, i.e., the lack of phosphate groups and the presence of uronic acids.


Assuntos
Lipopolissacarídeos/química , Antígenos O/química , Plesiomonas/química , Sequência de Carboidratos , Lipopolissacarídeos/isolamento & purificação , Ressonância Magnética Nuclear Biomolecular , Antígenos O/isolamento & purificação , Oligossacarídeos/química , Oligossacarídeos/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
18.
Environ Pollut ; 257: 113493, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31753632

RESUMO

Antibiotic resistance is known to impact treatment efficiency of Plesiomonas infections negatively with fatal outcomes. This study investigated antibiogram fingerprint of P. shigelloides (n = 182) isolated from three South Africa rivers using the disc diffusion technique. Environmental pollution and analogous health risk (given infections) that could associate with the freshwaters and empirical treatment of Plesiomonas were assessed using Antibiotic Resistance Index (ARI) and Multiple Antibiotic Resistance Indices (MARI), respectively. Thirteen EUCAST recommended (ERAs) and eleven non-recommended antibiotics (NAs) used as first line agents in the treatment of gastroenteritis and extraintestinal infections were tested. Resistance against ERAs decreased from cefoxitin (37.91%), cefuroxime (35.17%), cefepime (31.87%), ceftriaxone (29.67%), ciprofloxacin (18.13%), trimethoprim-sulfamethoxazole (10.44%), piperacillin/tazobactam (8.79%), ertapenem (4.95%), norfloxacin (4.40%), levofloxacin (2.75%), meropenem (1.10%) to imipenem (0.55%). The isolates had higher resistance (≥36.07%) against NAs but were susceptible to amikacin (67.58%), gentamycin (73.08%), and tetracycline (80.77%). MARI of the isolates were significantly different between ERAs and NAs (P-value < 0.05) and had an average of 0.17 ±â€¯0.18 and 0.45 ±â€¯0.13, respectively. About 33.87% and 95.63% of the isolates had MARI value from 0.23 to 0.62 and 0.27-0.82 to ERAs and NAs, respectively. Also, ERAs-based and NAs-based ARI across sampling units showed significantly different (P-value < 0.05) means of 0.18 ±â€¯0.09 and 0.46 ±â€¯0.05, respectively. MARI attributed low risk of empirical treatment to recommended antibiotics but higher risk to non-recommended antibiotics. Model estimated successful and unsuccessful empirical treatment of infections risks due to resistance in the isolates using recommended antibiotics as 65.93% and 34.07%, respectively; 1.65% and 98.35% in the case of non-recommended antibiotics, respectively. ARI based on recommended antibiotics identified potential environmental pollutions in a number of sites. Resistance in freshwater P. shigelloides especially against cephalosporin, quinolones and fluoroquinolones is distressing and might suggests high pollution of the freshwaters in the Eastern Cape Province.


Assuntos
Farmacorresistência Bacteriana/genética , Poluição Ambiental/estatística & dados numéricos , Plesiomonas/fisiologia , Cefalosporinas , Fluoroquinolonas , Água Doce , Humanos , Testes de Sensibilidade Microbiana , Medição de Risco , África do Sul , beta-Lactamas
19.
Lett Appl Microbiol ; 69(6): 411-416, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31563155

RESUMO

Plesiomonas shigelloides is a common pathogen of aquatic animals and can pose a certain hazard to aquaculture. Here, we aimed to develop a loop-mediated isothermal amplification (LAMP) method for the visual detection of P. shigelloides to aid the diagnosis of infections caused by this pathogen in aquatic animals. We used LAMP to amplify P. shigelloides DNA and combined it with calcein or nucleic acid dipstick assay (NADA) to visualize the amplified products. The optimal LAMP amplification temperature was 64°C, and the reaction lasted for 50 min. The limit of detection of recombinant plasmids containing the target gene using the LAMP method was 2·0 × 102 copies per µl, which is ten times higher than that using conventional polymerase chain reaction (PCR). LAMP products could be visualized without agarose gel electrophoresis. We tested 85 fish specimens using the established LAMP method and conventional PCR. The detection rate was 42·4% using the LAMP method and 34·1% using conventional PCR. Based on our results, the LAMP method combined with calcein or NADA is a rapid, specific, sensitive and accurate method for visual detection of fish-derived P. shigelloides and can be used for the laboratory diagnosis of infections caused by it. SIGNIFICANCE AND IMPACT OF THE STUDY: The combination of loop-mediated isothermal amplification (LAMP) and calcein and nucleic acid dipstick assay (NADA) provided a rapid, specific and sensitive method for detecting Plesiomonas shigelloides, which is an important pathogen that causes diseases in aquatic animals worldwide. In the present study, the LAMP method showed a higher detection rate than conventional PCR for P. shigelloides using templates from 85 fish specimens. Thus, the LAMP method could be a reliable and convenient tool for diagnosing diseases in aquatic animals in the laboratory.


Assuntos
DNA Bacteriano/análise , Técnicas de Amplificação de Ácido Nucleico/métodos , Plesiomonas/isolamento & purificação , Animais , Aquicultura , Peixes/microbiologia , Plesiomonas/genética , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade
20.
Antonie Van Leeuwenhoek ; 112(12): 1815-1826, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31372945

RESUMO

Plesiomonas shigelloides is a Gram-negative rod-shaped bacterium which has been isolated from humans, animals and the environment. It has been associated with diarrhoeal disease in humans and various epizootic diseases in animals. In this study P. shigelloides strains were isolated from the faecal material of a captive Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis; YFP) living in semi-natural conditions in China. Plesiomonas shigelloides strain EE2 was subjected to whole genome sequencing. The draft genome was then compared to the genome sequences of ten other P. shigelloides isolates using the Pathosystems Resource Integration Center pipeline. In addition to several virulence factors which have been previously reported, we are proposing new candidate virulence factors such as a repeats-in-toxin protein, lysophospholipase, a twin-arginine translocation system and the type VI secretion effector Phospholipase A1.


Assuntos
Plesiomonas/genética , Plesiomonas/isolamento & purificação , Toninhas/microbiologia , Fatores de Virulência/genética , Animais , China , Fezes/microbiologia , Genoma Bacteriano , Sequenciamento Completo do Genoma
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