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Frontiers in Cellular and Infection... 2024Acute haemorrhagic diarrhoea syndrome (AHDS) in dogs is a condition of unknown aetiology. is suspected to play a role in the disease as it was commonly found in dogs...
INTRODUCTION
Acute haemorrhagic diarrhoea syndrome (AHDS) in dogs is a condition of unknown aetiology. is suspected to play a role in the disease as it was commonly found in dogs suffering from AHDS during a Norwegian outbreak in 2019. The role of this bacterium as a constituent of the canine gut microbiota is unknown, hence this study set out to investigate its occurrence in healthy dogs using metagenomics.
MATERIALS AND METHODS
To decrease the likelihood of false detection, we established a metagenomic threshold for by spiking culture-negative stool samples with a range of bacterial dilutions and analysing these by qPCR and shotgun metagenomics. The detection limit for was determined and used to establish a metagenomic threshold. The threshold was validated on naturally contaminated faecal samples with known cultivation status for . Finally, the metagenomic threshold was used to determine the occurrence of in shotgun metagenomic datasets from canine faecal samples (n=362) collected in the HUNT One Health project.
RESULTS
The metagenomic assay and qPCR had a detection limit of 1.1x10 CFU per faecal sample, which corresponded to a Cq value of 31.4 and 569 unique mer counts by shotgun metagenomics. Applying this metagenomic threshold to 362 faecal metagenomic datasets from healthy dogs, was found in only 1.1% (95% CI [0.0, 6.8]) of the samples, and then in low relative abundances (median: 0.04%; range: 0.00 to 0.81%). The sensitivity of the qPCR and shotgun metagenomics assay was low, as only 40% of culture-positive samples were also positive by qPCR and metagenomics.
DISCUSSION
Using our detection limit, the occurrence of in faecal samples from healthy dogs was low. Given the low sensitivity of the metagenomic assay, these results do not rule out a significantly higher occurrence of this bacterium at a lower abundance.
Topics: Dogs; Animals; Diarrhea; Feces; Metagenome; Providencia; Bacteria; Metagenomics
PubMed: 38481663
DOI: 10.3389/fcimb.2024.1305742 -
BMC Infectious Diseases Feb 2024In Kenya, diarrhoeal disease is the third leading cause of child mortality after malaria and pneumonia, accounting for nearly 100 deaths daily. We conducted a...
BACKGROUND
In Kenya, diarrhoeal disease is the third leading cause of child mortality after malaria and pneumonia, accounting for nearly 100 deaths daily. We conducted a cross-sectional study in Mukuru informal settlements to determine the bacteria associated with diarrhea and their ASTs to provide data essential for implementing appropriate intervention measures.
METHODS
Diarrheagenic children (≤ 5 years) were purposively recruited from outpatient clinics of Municipal City Council, Mukuru kwa Reuben, Medical Missionaries of Mary, and Mama Lucy Kibaki Hospital, Nairobi. A total of 219 stool samples were collected between May 2021 and August 2021. Stool culture was done on MacConkey and Salmonella Shigella agar, while the recovered bacteria were identified using VITEK®2GNID and polymerase chain reaction (PCR) used for E. coli pathotyping. Antibiotic Susceptibility Testing was done using VITEK®2AST-GN83.
RESULTS
At least one bacterial organism was recovered from each of the 213 (97%) participants, with 115 (56%) participants having only one bacterial type isolated, 90 (43%) with two types of bacteria, and 2 (1%) with three types of bacteria recovered. The most predominant bacteria recovered was 85% (93/109) non-pathogenic E.coli and 15% (16/109)of pathogenic E.coli, with 2 (1%) were Enterohemorrhagic E.coli (EHEC), 6 (3%) were Enteroaggregative E.coli (EAEC), and 8 (4%) were Enteropathogenic E.coli (EPEC). Other potentially pathogenic bacteria included Enterobacter sp (27.8%), Klebsiella sp 33(11%), and Citrobacter sp 15(4.7%). Pathogenic isolates such as Salmonella 7 (2%), Proteus mirabilis 16 (6%), Providencia alcalifaciens 1 (0.3%), and Shigella 16 (4.7%) were detected. Isolates such as Pantoea spp 2(0.67%), Raoultella planticola 1(0.33%), and Kluyvera 6(2%) rarely reported but implicated with opportunistic diarrhoeal disease were also recovered. Ampicillin, cefazolin, and sulfamethoxazole-trimethoprim were the least effective antimicrobials at 64%, 57%, and 55% resistance, respectively, while meropenem (99%), amikacin (99%), tazobactam piperacillin (96%), and cefepime (95%) were the most effective. Overall, 33(21%) of all enterics recovered were multidrug-resistant.
CONCLUSION
The study documented different bacteria potentially implicated with childhood diarrhea that were not limited to E. coli, Shigella, and Salmonella, as previously observed in Kenya. The strains were resistant to the commonly used antibiotics, thus narrowing the treatment options for diarrheal disease.
Topics: Child; Humans; Child, Preschool; Kenya; Cross-Sectional Studies; Diarrhea; Anti-Infective Agents; Enteropathogenic Escherichia coli; Bacteria; Salmonella; Shigella
PubMed: 38388369
DOI: 10.1186/s12879-024-09114-5 -
Archives of Razi Institute Jun 2023Probiotics have been used for over a century to prevent and treat diseases. They can reduce the effects of gastroenteritis and are now used to treat acute diarrhea. This...
Probiotics have been used for over a century to prevent and treat diseases. They can reduce the effects of gastroenteritis and are now used to treat acute diarrhea. This study aimed to evaluate the co-aggregative effects of probiotics bacteria against diarrheal causative bacteria. For this purpose, 11 isolates of probiotic bacteria were used in the current study, including three , one , two , three , and two isolates. All isolates were tested for antibiotic susceptibility, autoaggregation ability, adhesion ability, antibacterial activity, acid tolerance, and bile salts tolerance. The results showed that most of them had the ability to autoaggregate after 4 h, with the highest percentage of 57.14% for . For the antibiotic susceptibility test, all the isolates showed resistance against trimethoprim/sulfamethoxazole, except one isolate. Moreover, all the isolates, except one, were susceptible to both vancomycin and tetracycline. All tested isolates had adhesion ability with different survival rates, which reached 34.57% for in acidic conditions. Besides, the highest survival rate was 85.17%, which belonged to , for bile salt tolerance. Probiotic isolates had an antibacterial effect against diarrhea-causative bacteria with an inhibition diameter of 17-49 mm for different spp. and spp. isolates. Furthermore, the co-aggregation ability of probiotic isolates against diarrhea-causative bacteria was studied, and results showed that probiotic isolates had a co-aggregative effect against diarrhea-causative bacteria, , , and , after 24 h of incubation. The highest co-aggregative effect of probiotics isolates belonged to and against with a co-aggregation percentage of 100%, while the lowest co-aggregation rate was 14.29% against . The findings revealed the probiotic properties and co-aggregative effects of probiotic bacteria against diarrhea-causative bacteria.
Topics: Animals; Escherichia coli; Lactobacillus; Anti-Bacterial Agents; Bile Acids and Salts; Diarrhea; Probiotics
PubMed: 38028859
DOI: 10.22092/ARI.2022.359870.2494 -
Journal of Veterinary Research Sep 2023Universally, in microbiological diagnostics the detection of live bacteria is essential. Rapid identification of pathogens enables appropriate remedial measures to be...
INTRODUCTION
Universally, in microbiological diagnostics the detection of live bacteria is essential. Rapid identification of pathogens enables appropriate remedial measures to be taken. The identification of many bacteria simultaneously facilitates the determination of the characteristics of the accompanying microbiota and/or the microbiological complexity of a given environment.
MATERIAL AND METHODS
The effectiveness of the VITEK2 Compact automated microbial identification system and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS), analytical profile index (API) and Remel RapID tests were compared in identification of bacteria isolated from the alpaca gastrointestinal tract.
RESULTS
Most isolates were Gram-positive, such as and and , , and ; ; ; ; ; , , and (the last only isolated manually by API Coryne and the VITEK2 system and (CBC) card). was misidentified by MALDI-TOF MS as (currently ). Gram-positive and Gram-variable were also isolated. Gram-negative , , and ; ; subsp. ; and ; , and ; subsp. ; ; ; ; ; and were also found. The yeasts and were also present.
CONCLUSION
MALDI-TOF MS enabled the identification of pathogens and opportunistic pathogens from the alpaca gut which may represent a high risk to human and animal health.
PubMed: 37786852
DOI: 10.2478/jvetres-2023-0051 -
Journal of Insect Science (Online) May 2023Mexican fruit fly (Anastrepha ludens (Loew)) (Diptera: Tephritidae) represents a major threat to fruit production in the Western Hemisphere. Sterile insect technique is...
Mexican fruit fly (Anastrepha ludens (Loew)) (Diptera: Tephritidae) represents a major threat to fruit production in the Western Hemisphere. Sterile insect technique is used to suppress and eradicate wild populations. Success of this control method necessitates weekly production of hundreds of millions of flies, their sterilization by irradiation, and their aerial release. Diet needed to produce large fly numbers are conducive to the spread of bacteria. Pathogenic bacteria were isolated from 3 rearing facilities and from multiple sources: eggs, larvae, pupae and spent diet, and were found to include some isolates identified to the genus Providencia (Enterobacteriales: Morganellaceae). We identified 41 Providencia isolates and tested their pathogenicity to A. ludens. Based on 16s rRNA sequences, 3 groups were clustered into several species of Providencia with varying capacities to affect the Mexican fruit fly production. Isolates putatively identified as P. alcalifaciens/P. rustigianii were all pathogenic causing larval and pupal yield reduction of 46-64% and 37-57%, respectively. Among them, Providencia isolate 3006 was the most pathogenic reducing larval and pupae yield by 73 and 81%, respectively. Isolates identified as P. sneebia were not pathogenic. The final cluster, P. rettgeri/P. vermicola, were variable in pathogenicity with 3 isolates yielding like the control and the rest causing larval and pupal yield reduction of 26-53% and 23-51%, respectively. Isolates putatively identified as P. alcalifaciens/P. rustigianii were more virulent than P. rettgeri/P. vermicola. Accurate identification of species is needed to diagnose and monitor pathogenic versus nonpathogenic Providencia strains.
Topics: Animals; Tephritidae; Providencia; Virulence; RNA, Ribosomal, 16S; Ovum; Larva; Pupa
PubMed: 37220089
DOI: 10.1093/jisesa/iead024 -
Biology Feb 2023Parasitoids are promising biocontrol agents of the devastating fruit fly, . However, parasitoid performance is a function of several factors, including host-associated...
Parasitoids are promising biocontrol agents of the devastating fruit fly, . However, parasitoid performance is a function of several factors, including host-associated symbiotic bacteria. , , and are among the symbiotic bacteria commonly associated with , and they influence the eco-physiological functioning of this pest. However, whether these bacteria influence the interaction between this pest and its parasitoids is unknown. This study sought to elucidate the nature of the interaction of the parasitoids, , , and with as mediated by symbiotic bacteria. Three types of fly lines were used: axenic, symbiotic, and bacteria-mono-associated (, , and ). The suitable stages of each fly line were exposed to the respective parasitoid species and reared until the emergence of adult flies/parasitoids. Thereafter, data on the emergence and parasitoid fitness traits were recorded. No wasps emerged from the fly lines exposed to . The highest emergence of . and was recorded in the fly lines. The parasitoid progeny from the and fly lines had the longest developmental time and the largest body size. Conversely, parasitoid fecundity was significantly lower in the lines, whereas the lines significantly improved fecundity. These results elucidate some effects of bacterial symbionts on host-parasitoid interactions and their potential in enhancing parasitoid-oriented management strategies against .
PubMed: 36829551
DOI: 10.3390/biology12020274 -
PLoS Pathogens Sep 2022Bacteria from the genus Providencia are ubiquitous Gram-negative opportunistic pathogens, causing "travelers' diarrhea", urinary tract, and other nosocomial infections...
Lipopolysaccharide -mediated resistance to host antimicrobial peptides and hemocyte-derived reactive-oxygen species are the major Providencia alcalifaciens virulence factors in Drosophila melanogaster.
Bacteria from the genus Providencia are ubiquitous Gram-negative opportunistic pathogens, causing "travelers' diarrhea", urinary tract, and other nosocomial infections in humans. Some Providencia strains have also been isolated as natural pathogens of Drosophila melanogaster. Despite clinical relevance and extensive use in Drosophila immunity research, little is known about Providencia virulence mechanisms and the corresponding insect host defenses. To close this knowledge gap, we investigated the virulence factors of a representative Providencia species-P. alcalifaciens which is highly virulent to fruit flies and amenable to genetic manipulations. We generated a P. alcalifaciens transposon mutant library and performed an unbiased forward genetics screen in vivo for attenuated mutants. Our screen uncovered 23 mutants with reduced virulence. The vast majority of them had disrupted genes linked to lipopolysaccharide (LPS) synthesis or modifications. These LPS mutants were sensitive to cationic antimicrobial peptides (AMPs) in vitro and their virulence was restored in Drosophila mutants lacking most AMPs. Thus, LPS-mediated resistance to host AMPs is one of the virulence strategies of P. alcalifaciens. Another subset of P. alcalifaciens attenuated mutants exhibited increased susceptibility to reactive oxygen species (ROS) in vitro and their virulence was rescued by chemical scavenging of ROS in flies prior to infection. Using genetic analysis, we found that the enzyme Duox specifically in hemocytes is the source of bactericidal ROS targeting P. alcalifaciens. Consistently, the virulence of ROS-sensitive P. alcalifaciens mutants was rescued in flies with Duox knockdown in hemocytes. Therefore, these genes function as virulence factors by helping bacteria to counteract the ROS immune response. Our reciprocal analysis of host-pathogen interactions between D. melanogaster and P. alcalifaciens identified that AMPs and hemocyte-derived ROS are the major defense mechanisms against P. alcalifaciens, while the ability of the pathogen to resist these host immune responses is its major virulence mechanism. Thus, our work revealed a host-pathogen conflict mediated by ROS and AMPs.
Topics: Animals; Antimicrobial Peptides; Drosophila melanogaster; Hemocytes; Humans; Lipopolysaccharides; Oxygen; Providencia; Reactive Oxygen Species; Virulence Factors
PubMed: 36084158
DOI: 10.1371/journal.ppat.1010825 -
IScience Jul 2022Adaptive immunity can target a nearly infinite range of antigens, yet it is tempered by tolerogenic mechanisms that limit autoimmunity. Such immunological tolerance,...
Adaptive immunity can target a nearly infinite range of antigens, yet it is tempered by tolerogenic mechanisms that limit autoimmunity. Such immunological tolerance, however, creates a gap in adaptive immunity against microbes decorated with self-like antigens as a form of molecular mimicry. Our results demonstrate that the innate immune lectin galectin-7 (Gal-7) binds a variety of distinct microbes, all of which share features of blood group-like antigens. Gal-7 binding to each blood group expressing microbe, including strains of , , and , results in loss of microbial viability. Although Gal-7 also binds red blood cells (RBCs), this interaction does not alter RBC membrane integrity. These results demonstrate that Gal-7 recognizes a diverse range of microbes, each of which use molecular mimicry while failing to induce host cell injury, and thus may provide an innate form of immunity against molecular mimicry.
PubMed: 35754739
DOI: 10.1016/j.isci.2022.104482 -
MicroPublication Biology 2022experiences and microbiome have been shown to shape its responses to certain stimuli; a recent study found that grown on JUb39 exhibited increased attraction to that...
experiences and microbiome have been shown to shape its responses to certain stimuli; a recent study found that grown on JUb39 exhibited increased attraction to that same growth bacteria while also lowered repulsion to the odor 1-octanol (O’Donnell et al. 2020). This prompted us to ask whether other strains of bacteria could likewise alter responses to bacterial food and volatile chemicals. So, to expand upon current knowledge, we cultured wild-type (N2) on an unidentified ( sp?), (MSPm1), (MYb11), (JUb19), or strain ( sp?). After several generations, we examined how their choice of bacterial food was affected. In addition, we looked at their response to the olfactory stimuli 2-butanone; 2,3-butanedione; 2,3-pentanedione; and 2-nonanone, as well as their response to the gustatory stimulus sodium chloride. Interestingly, we found that growth on any of these bacterial strains led to their bacterial preferences and behavioral responses to 2-butanone; 2,3-pentanedione; diacetyl; and sodium chloride remaining unchanged. However, we also saw that showed a preference for MSPm1 and sp? to HB101, and HB101 to MYb11. Furthermore, worms that are grown on MSPm1 showed stronger attraction to a 1:10 dilution of 2-nonanone (AWB-sensed odorant) as compared to worms grown on the other bacterial strains.
PubMed: 35622520
DOI: 10.17912/micropub.biology.000535 -
Microbiology Resource Announcements Feb 2022Eight Providencia alcalifaciens isolates from eight different dogs in Norway with acute hemorrhagic diarrhea were sequenced. Based on Illumina and Oxford Nanopore...
Eight Providencia alcalifaciens isolates from eight different dogs in Norway with acute hemorrhagic diarrhea were sequenced. Based on Illumina and Oxford Nanopore Technologies sequencing, all of the genomes were complete and closed after hybrid assembly.
PubMed: 35175129
DOI: 10.1128/mra.00955-21