scholarly journals The Possible Transmission and Potential Enterotoxicity of Bacillus cereus on Lettuce Farms in Five Chinese Provinces

2021 ◽  
Vol 12 ◽  
Author(s):  
Yang Qu ◽  
Chao Wei ◽  
Xiaohang Dai ◽  
Yalong Bai ◽  
Xin Zhao ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Potential Risk ◽  
Trace Analysis ◽  
Multilocus Sequence Typing ◽  
Soil Samples ◽  
Foodborne Diseases ◽  
Human Pathogen ◽  
Toxin Genes ◽  
Positive Rate ◽  
Sequence Types

Bacillus cereus is a well-characterized human pathogen that produces toxins associated with diarrheal and emetic foodborne diseases. To investigate the possible transmission of B. cereus on lettuce farms in China and determine its enterotoxicity, (I) a total of 524 samples (lettuce: 332, soil: 69, water: 57, manure: 57, pesticide: 9) were collected from 46 lettuce farms in five Chinese provinces, (II) multilocus sequence typing (MLST) was used to classify B. cereus isolates and for trace analysis, and (III) the presence of toxin genes and enterotoxins (Hbl and Nhe) was detected in 68 strains. The results showed that one hundred and sixty-one lettuce samples (48.5%) tested positive for B. cereus at levels ranging from 10 to 5.3 × 104 CFU/g. Among the environmental sample categories surveyed, the highest positive rate was that of the pesticide samples at 55.6%, followed by soil samples at 52.2% and manure samples at 12.3%. Moreover, one hundred isolates of B. cereus yielded 68 different sequence types (STs) and were classified into five phylogenetic clades. Furthermore, Nhe toxin genes (nheA, nheB, nheC) were broadly distributed and identified in all 68 strains (100%), while Hbl toxin genes (hblA, hblC, hblD) were present in 61 strains (89.7%), entFM was detected in 62 strains (91.2%), and cytK was found in 29 strains (42.6%). All strains were negative for ces. As for the enterotoxin, Nhe was observed in all 68 isolates carrying nheB, while Hbl was present in 76.5% (52/68) of the strains harboring hblC. This study is the first report of possible B. cereus transmission and of its potential enterotoxicity on lettuce farms in China. The results showed that soil and pesticides are the main sources of B. cereus on lettuce farms in China, and the possible transmission routes are as follows: soil-lettuce, manure-lettuce, pesticide-lettuce, manure-soil-lettuce, and water-manure-soil-lettuce. Furthermore, the B. cereus isolates, whether from lettuce or the environment, pose a potential risk to health.

Fantastic yeasts and where to find them: the discovery of a predominantly clonal Cryptococcus deneoformans population in Saudi Arabian soils

2019 ◽  
Vol 95 (9) ◽  
Author(s):  
Himeshi Samarasinghe ◽  
Renad Aljohani ◽  
Carlene Jimenez ◽  
Jianping Xu
Keyword(s):  
Saudi Arabia ◽  
Middle East ◽  
Multilocus Sequence Typing ◽  
Ecological Niche ◽  
Saudi Arabian ◽  
Soil Samples ◽  
Recombinant Product ◽  
Desert Climate ◽  
Sequence Types ◽  
Major Sequence

ABSTRACT Cryptococcus deneoformans is an opportunist yeast pathogen and causative agent of meningoencephalitis in humans. It is known to be mainly distributed in temperate climates. Most of our current understanding of this species has come from clinical isolates, leaving environmental populations largely unexplored. The Middle East remains one such underexplored area with no published study to date investigating cryptococcal diversity in soil. In this study, we identified 76 C. deneoformans isolates from a survey of 562 soil samples collected from six cities in Saudi Arabia. Multilocus sequence typing revealed the presence of two major sequence types (STs), ST160 (n = 63) and ST294 (n = 9), along with four singleton STs, three of which were novel. One novel ST, ST613, was likely a recombinant product between ST160 and ST294. Among the 76 isolates, 75 belonged to mating type (MAT)α while one isolate was MATa. Our analyses suggest that the Saudi Arabian C. deneoformans population likely reproduces both asexually and sexually in nature. Our study is the first to report the occurrence of C. deneoformans in a desert climate, representing a novel expansion to this species’ currently known ecological niche.

scholarly journals Multilocus Sequence Typing Scheme for Bacteria of the Bacillus cereus Group

2004 ◽  
Vol 70 (1) ◽  
pp. 191-201 ◽  
Author(s):  
Erlendur Helgason ◽  
Nicolas J. Tourasse ◽  
Roger Meisal ◽  
Dominique A. Caugant ◽  
Anne-Brit Kolstø
Keyword(s):  
Population Structure ◽  
Bacillus Cereus ◽  
Multilocus Sequence Typing ◽  
Sequence Data ◽  
Housekeeping Genes ◽  
Industrial Applications ◽  
Enzyme Electrophoresis ◽  
Mlst Scheme ◽  
High Level ◽  
Sequence Types

ABSTRACT In this study we developed a multilocus sequence typing (MLST) scheme for bacteria of the Bacillus cereus group. This group, which includes the species B. cereus, B. thuringiensis, B. weihenstephanensis, and B. anthracis, is known to be genetically very diverse. It is also very important because it comprises pathogenic organisms as well as bacteria with industrial applications. The MLST system was established by using 77 strains having various origins, including humans, animals, food, and soil. A total of 67 of these strains had been analyzed previously by multilocus enzyme electrophoresis, and they were selected to represent the genetic diversity of this group of bacteria. Primers were designed for conserved regions of housekeeping genes, and 330- to 504-bp internal fragments of seven such genes, adk, ccpA, ftsA, glpT, pyrE, recF, and sucC, were sequenced for all strains. The number of alleles at individual loci ranged from 25 to 40, and a total of 53 allelic profiles or sequence types (STs) were distinguished. Analysis of the sequence data showed that the population structure of the B. cereus group is weakly clonal. In particular, all five B. anthracis isolates analyzed had the same ST. The MLST scheme which we developed has a high level of resolution and should be an excellent tool for studying the population structure and epidemiology of the B. cereus group.

Sidrophore Production and Phosphate Solubilization by Bacillus cereus and Pseudomonas fluorescens Isolated from Iraqi Soils and Soil Characterization

2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Zaid Raad Abbas ◽  
Aqeel Mohammed Majeed Al-Ezee ◽  
Sawsan H
Keyword(s):  
Bacillus Cereus ◽  
Pseudomonas Fluorescens ◽  
Phosphate Solubilization ◽  
Bacterial Species ◽  
Nutrient Status ◽  
Bacterial Count ◽  
Soil Samples ◽  
Phosphate Solubilizing Bacteria ◽  
Clear Zone ◽  
Zone Formation

This study was conducted to explore the ability of Pseudomonas fluorescens and Bacillus cereus to solubilizing a phosphate in soil for enhancing the planting growth and, its relation with soill characterization. The isolates were identified as P.fluorescens and B. cereus using convential analysis and, its phosphate solubilization ability and sidrophore was shown by the clear zone formation on National Botanical Research Institute���s Phosphate medium. Moreover, Pseudomonas fluorescens isolates (n = 9) and three of B. cereus isolated from agricultural area in Baghdad university, Mustansiriyah university and Diyala bridge. Results displayed that bacterial count were varied in soil samples according to their region, and ranging from 30 to 60 *10 2 CFU/g in Baghdad university soil to 10���20 *10 2 CFU/g in Mustansiriyah university soil, the Baghdad soil macronutrient which included: NH4, NO3, P, and K were, 8.42, 20.53, 19.09, 218.73 respectively, While the physio analysis revealed that the mean of pH was 7.3 and EC was 8.63. on the other hand the micronutrient analysis indicated that the soil samples were included Ca, Fe, Mn, Zn and Cu which gave their mean 5025.9, 8.9, 4.9, 0.5 and 1.5 respectevily. Results revealed that all isolated bacteria (9 isolates of P.fluorescens and three isolates of B. cereus gave ahalo zone which mean their ability to be phosphate solubilizing bacteria at 100%. Results revealed that all isolated bacteria were detected a ability to produce high levels from chelating agents (siderophores)) by P.fluorescens and. B cereus at 100%, when appeared ahalo clear zone. Furthermore, the high levels of phosphate solubilization and siderophore production were grouped in bacterial species isolated from Iraqi soils. might be attributed to many soil factors such as soil nutrient status, soil acidity, water content, organic matter and soil enzyme activities.

scholarly journals Phenotypic and Molecular Analysis of Penicillin-Nonsusceptible Streptococcus pneumoniae Isolates in Poland

2006 ◽  
Vol 51 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Ewa Sadowy ◽  
Radosław Izdebski ◽  
Anna Skoczyńska ◽  
Paweł Grzesiowski ◽  
Marek Gniadkowski ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Molecular Analysis ◽  
Gel Electrophoresis ◽  
Multilocus Sequence Typing ◽  
Susceptibility Testing ◽  
Bacterial Pathogen ◽  
Pulsed Field Gel Electrophoresis ◽  
Pulsed Field ◽  
Related Clone ◽  
Sequence Types

ABSTRACT β-Lactams are the drugs of choice for the treatment of infections caused by the important bacterial pathogen Streptococcus pneumoniae. The recent growth of resistance of this organism to penicillin observed worldwide is of the highest concern. In this study, using 887 surveillance pneumococcal isolates recovered in Poland from 1998 to 2002, we observed the increase in penicillin nonsusceptibility from 8.7% to 20.3%. All of the 109 penicillin-nonsusceptible S. pneumoniae (PNSP) isolates identified, together with 22 archival PNSP isolates from 1995 to 1997, were subsequently analyzed by susceptibility testing, serotyping, profiling of pbp genes, pulsed-field gel electrophoresis, and multilocus sequence typing (MLST). Four predominant serotypes, serotypes 6B, 9V, 14, and 23F, characterized 85.5% of the isolates. MLST revealed the presence of 34 sequence types, 15 of which were novel types. Representatives of seven multiresistant international clones (Spain23F-1, Spain6B-2, Spain9V-3, Taiwan23F-15, Poland23F-16, Poland6B-20, and Sweden15A-25) or their closely related variants comprised the majority of the study isolates. The spread of Spain9V-3 and its related clone of serotype 14/ST143 has remarkably contributed to the recent increase in penicillin resistance in pneumococci in the country.

scholarly journals Population Genetics and Characterization ofCampylobacter jejuniIsolates from Western Jackdaws and Game Birds in Finland

2018 ◽  
Vol 85 (4) ◽  
Author(s):  
Sara Kovanen ◽  
Mirko Rossi ◽  
Mari Pohja-Mykrä ◽  
Timo Nieminen ◽  
Mirja Raunio-Saarnisto ◽  
...  
Keyword(s):  
Host Specificity ◽  
Campylobacter Jejuni ◽  
Multilocus Sequence Typing ◽  
Wild Birds ◽  
Whole Genome ◽  
Mallard Duck ◽  
Content Type ◽  
Game Birds ◽  
Hygienic Measures ◽  
Sequence Types

ABSTRACTPoultry are considered a major reservoir and source of human campylobacteriosis, but the roles of environmental reservoirs, including wild birds, have not been assessed in depth. In this study, we isolated and characterizedCampylobacter jejunifrom western jackdaws (n= 91, 43%), mallard ducks (n= 82, 76%), and pheasants (n= 9, 9%). Most of the western jackdaw and mallard duckC. jejuniisolates represented multilocus sequence typing (MLST) sequence types (STs) that diverged from those previously isolated from human patients and various animal species, whereas all pheasant isolates represented ST-19, a common ST among human patients and other hosts worldwide. Whole-genome MLST revealed that mallard duck ST-2314 and pheasant ST-19 isolates represented bacterial clones that were genetically highly similar to human isolates detected previously. Further analyses revealed that in addition to a divergent ClonalFrame genealogy, certain genomic characteristics of the western jackdawC. jejuniisolates, e.g., a novelcdtABCgene cluster and the type VI secretion system (T6SS), may affect their host specificity and virulence. Game birds may thus pose a risk for acquiring campylobacteriosis; therefore, hygienic measures during slaughter and meat handling warrant special attention.IMPORTANCEThe roles of environmental reservoirs, including wild birds, in the molecular epidemiology ofCampylobacter jejunihave not been assessed in depth. Our results showed that game birds may pose a risk for acquiring campylobacteriosis, because they hadC. jejunigenomotypes highly similar to human isolates detected previously. Therefore, hygienic measures during slaughter and meat handling warrant special attention. On the contrary, a unique phylogeny was revealed for the western jackdaw isolates, and certain genomic characteristics identified among these isolates are hypothesized to affect their host specificity and virulence. Comparative genomics within sequence types (STs), using whole-genome multilocus sequence typing (wgMLST), and phylogenomics are efficient methods to analyze the genomic relationships ofC. jejuniisolates.

scholarly journals Bacteriophages LIMElight and LIMEzero of Pantoea agglomerans, Belonging to the “phiKMV-Like Viruses”

2011 ◽  
Vol 77 (10) ◽  
pp. 3443-3450 ◽  
Author(s):  
Evelien M. Adriaenssens ◽  
Pieter-Jan Ceyssens ◽  
Vincent Dunon ◽  
Hans-Wolfgang Ackermann ◽  
Johan Van Vaerenbergh ◽  
...  
Keyword(s):  
Soil Samples ◽  
Pantoea Agglomerans ◽  
Open Reading Frames ◽  
Human Pathogen ◽  
Content Type ◽  
Host Diversity ◽  
Double Stranded Dna ◽  
Opportunistic Human Pathogen ◽  
Reading Frames

ABSTRACTPantoea agglomeransis a common soil bacterium used in the biocontrol of fungi and bacteria but is also an opportunistic human pathogen. It has been described extensively in this context, but knowledge of bacteriophages infecting this species is limited. Bacteriophages LIMEzero and LIMElight ofP. agglomeransare lytic phages, isolated from soil samples, belonging to thePodoviridaeand are the firstPantoeaphages of this family to be described. The double-stranded DNA (dsDNA) genomes (43,032 bp and 44,546 bp, respectively) encode 57 and 55 open reading frames (ORFs). Based on the presence of an RNA polymerase in their genomes and their overall genome architecture, these phages should be classified in the subfamily of theAutographivirinae, within the genus of the “phiKMV-like viruses.” Phylogenetic analysis of all the sequenced members of theAutographivirinaesupports the classification of phages LIMElight and LIMEzero as members of the “phiKMV-like viruses” and corroborates the subdivision into the different genera. These data expand the knowledge ofPantoeaphages and illustrate the wide host diversity of phages within the “phiKMV-like viruses.”

Nonencapsulated or nontypeableHaemophilus influenzaeare more likely than their encapsulated or serotypeable counterparts to have mutations in their fucose operon

2011 ◽  
Vol 57 (12) ◽  
pp. 982-986 ◽  
Author(s):  
Michelle L. Shuel ◽  
Kathleen E. Karlowsky ◽  
Dennis K.S. Law ◽  
Raymond S.W. Tsang
Keyword(s):  
Nucleotide Sequence ◽  
Haemophilus Influenzae ◽  
Dna Sequencing ◽  
Multilocus Sequence Typing ◽  
Population Biology ◽  
Housekeeping Genes ◽  
Sequence Variations ◽  
Sequence Types ◽  
Complete Deletion

Population biology of Haemophilus influenzae can be studied by multilocus sequence typing (MLST), and isolates are assigned sequence types (STs) based on nucleotide sequence variations in seven housekeeping genes, including fucK. However, the ST cannot be assigned if one of the housekeeping genes is absent or cannot be detected by the current protocol. Occasionally, strains of H. influenzae have been reported to lack the fucK gene. In this study, we examined the prevalence of this mutation among our collection of H. influenzae isolates. Of the 704 isolates studied, including 282 encapsulated and 422 nonencapsulated isolates, nine were not typeable by MLST owing to failure to detect the fucK gene. All nine fucK-negative isolates were nonencapsulated and belonged to various biotypes. DNA sequencing of the fucose operon region confirmed complete deletion of genes in the operon in seven of the nine isolates, while in the remaining two isolates, some of the genes were found intact or in parts. The significance of these findings is discussed.

scholarly journals Virulence Gene Profile, Antimicrobial Resistance and Multilocus Sequence Typing of Salmonella enterica Subsp. enterica Serovar Enteritidis from Chickens and Chicken Products

Animals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 97
Author(s):  
Zunita Zakaria ◽  
Latiffah Hassan ◽  
Zawiyah Sharif ◽  
Norazah Ahmad ◽  
Rohaya Mohd Ali ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Multilocus Sequence Typing ◽  
Salmonella Enteritidis ◽  
Molecular Subtypes ◽  
Actin Binding ◽  
Diffusion Method ◽  
Genetic Characteristics ◽  
Meat Samples ◽  
Sequence Types

This study was undertaken to determine the virulence, antimicrobial resistance and molecular subtypes of Salmonella in the Central Region of Peninsular Malaysia. A total of 45 Salmonella Enteritidis were detected from live chicken (cloacal swab), and chicken products (fresh and ready-to-eat meat) samples upon cultural isolation and serotyping. Similarly, an antimicrobial susceptibility test based on the Kirby Bauer disk diffusion method as well as antimicrobial resistance AMR genes, virulence determinants and multilocus sequence typing (MLST) typing were conducted after the Whole Genome Sequencing and analysis of the isolates. The results indicate that sequence types ST1925 (63.7%), and ST11 (26.5%) were the predominant out of the seven sequence types identified (ST292, ST329, ST365, ST423 and ST2132). The phenotypic antimicrobial profile corresponds to the genotypic characterization in that the majority of the isolates that exhibited tetracycline, gentamycin and aminoglycoside resistance; they also possessed the tetC and blaTEM β-Lactam resistance genes. However, isolates from cloacal swabs showed the highest number of resistance genes compared to the chicken products (fresh and ready-to-eat meat) samples. Furthermore, most of the virulence genes were found to cluster in the Salmonella pathogenicity island (SPI). In this study, all the isolates were found to possess SPI-1, which codes for the type III secretion system, which functions as actin-binding proteins (SptP and SopE). The virulence plasmid (VP) genes (spvB, spvC) were present in all genotypes except ST365. The findings of this study, particularly with regard to the molecular subtypes and AMR profiles of the Salmonella Enteritidis serotype shows multidrug-resistance features as well as genetic characteristics indicative of high pathogenicity.

Sign in / Sign up

Export Citation Format

Share Document