scholarly journals Improvement ofBartonella henselaeDNA Detection in Cat Blood Samples by Combining Molecular and Culture Methods

2018 ◽  
Vol 56 (5) ◽  
Author(s):  
Marina Rovani Drummond ◽  
Bruno Grosselli Lania ◽  
Pedro Paulo Vissotto de Paiva Diniz ◽  
Rovilson Gilioli ◽  
Daniele Masselli Rodrigues Demolin ◽  
...  
Keyword(s):  
Bloodstream Infection ◽  
Liquid Culture ◽  
Bartonella Henselae ◽  
False Negative ◽  
Reservoir Host ◽  
Southeastern Brazil ◽  
Culture Methods ◽  
Content Type ◽  
Worldwide Distribution ◽  
Reservoir Hosts

ABSTRACTBartonellaspp. are bacteria of worldwide distribution that cause asymptomatic to fatal infections in animals and humans. The most common zoonotic species isBartonella henselae, for which cats are the major natural reservoir host. To better understandBartonellasp. diagnostic limitations, we determined the frequency of bloodstream infection in 112 cats by comparing and combining the results of multiple conventional and nested PCRs from blood and liquid culture samples. Using liquid culture conventional PCR,Bartonellasp. DNA was amplified from 27.7% of samples (31/112) compared to 90.2% of samples (101/112) by combining nested PCR from blood and liquid culture, indicating that PCR testing of more than one type of sample provides better sensitivity than a standalone PCR and that bloodstream infection is very frequent among cats in southeastern Brazil. This study reinforces the need for multistep testing forBartonellasp. infection to prevent false-negative diagnostic results, even in reservoir hosts such as cats that typically maintain higher bacteremia levels.

scholarly journals Seasonal Prevalence of Lyme Disease Spirochetes in a Heterothermic Mammal, the Edible Dormouse (Glis glis)

2014 ◽  
Vol 80 (12) ◽  
pp. 3615-3621 ◽  
Author(s):  
Joanna Fietz ◽  
Jürgen Tomiuk ◽  
Franz-Rainer Matuschka ◽  
Dania Richter
Keyword(s):  
Lyme Disease ◽  
Reservoir Host ◽  
Glis Glis ◽  
Content Type ◽  
Transmission Cycle ◽  
Western Germany ◽  
Edible Dormice ◽  
Study Sites ◽  
Reservoir Hosts

ABSTRACTIn Europe, dormice serve as competent reservoir hosts for particular genospecies of the tick-borne agent of Lyme disease (LD) and seem to support them more efficiently than do mice or voles. The longevity of edible dormice (Glis glis) and their attractiveness for ticks may result in a predominance of LD spirochetes in ticks questing in dormouse habitats. To investigate the role of edible dormice in the transmission cycle of LD spirochetes, we sampled skin tissue from the ear pinnae of dormice inhabiting five different study sites in south western Germany. Of 501 edible dormice, 12.6% harbored DNA of LD spirochetes. Edible dormice were infected most frequently with the pathogenic LD spirocheteBorrelia afzelii. The DNA ofB. gariniiandB. bavariensiswas detected in ca. 0.5% of the examined individuals. No spirochetal DNA was detectable in the skin of edible dormice until July, 6 weeks after they generally start to emerge from their obligate hibernation. Thereafter, the prevalence of spirochetal DNA in edible dormice increased during the remaining period of their 4 to 5 months of activity, reaching nearly 40% in September. Males were more than four times more likely to harbor LD spirochetes than females, and yearlings were almost twice more likely to be infected than adults. The seasonality of the prevalence of LD spirochetes in edible dormice was pronounced and may affect their role as a reservoir host in respect to other hosts.

scholarly journals Replication of Boid Inclusion Body Disease-Associated Arenaviruses Is Temperature Sensitive in both Boid and Mammalian Cells

2014 ◽  
Vol 89 (2) ◽  
pp. 1119-1128 ◽  
Author(s):  
Jussi Hepojoki ◽  
Anja Kipar ◽  
Yegor Korzyukov ◽  
Lesley Bell-Sakyi ◽  
Olli Vapalahti ◽  
...  
Keyword(s):  
Body Temperature ◽  
Inclusion Body ◽  
Mammalian Cells ◽  
Cytoplasmic Inclusion ◽  
Reservoir Host ◽  
The Body ◽  
Species Barrier ◽  
Content Type ◽  
Inclusion Body Disease ◽  
Reservoir Hosts

ABSTRACTBoid inclusion body disease (BIDB) is a fatal disease of boid snakes, the etiology of which has only recently been revealed following the identification of several novel arenaviruses in diseased snakes. BIBD-associated arenaviruses (BIBDAV) are genetically divergent from the classical Old and New World arenaviruses and also differ substantially from each other. Even though there is convincing evidence that BIBDAV are indeed the etiological agent of BIBD, the BIBDAV reservoir hosts—if any exist besides boid snakes themselves—are not yet known. In this report, we use University of Helsinki virus (UHV; a virus that we isolated from aBoa constrictorwith BIBD) to show that BIBDAV can also replicate effectively in mammalian cells, including human cells, provided they are cultured at 30°C. The infection induces the formation of cytoplasmic inclusion bodies (IB), comprised mainly of viral nucleoprotein (NP), similar to those observed in BIBD and in boid cell cultures. Transferring infected cells from 30°C to 37°C ambient temperature resulted in progressive declines in IB formation and in the amounts of viral NP and RNA, suggesting that BIBDAV growth is limited at 37°C. These observations indirectly indicate that IB formation is linked to viral replication. In addition to mammalian and reptilian cells, UHV infected arthropod (tick) cells when grown at 30°C. Even though our findings suggest that BIBDAV have a high potential to cross the species barrier, their inefficient growth at mammalian body temperatures indicates that the reservoir hosts of BIBDAV are likely species with a lower body temperature, such as snakes.IMPORTANCEThe newly discovered boid inclusion body disease-associated arenaviruses (BIBDAV) of reptiles have drastically altered the phylogeny of the familyArenavirus. Prior to their discovery, known arenaviruses were considered mainly rodent-borne viruses, with each arenavirus species having its own reservoir host. BIBDAV have so far been demonstrated in captive boid snakes, but their possible reservoir host(s) have not yet been identified. Here we show, using University of Helsinki virus as a model, that these viruses are able to infect mammalian (including human) and arthropod cells. Our results providein vitroproof of the considerable ability of arenaviruses to cross species barriers. However, our data indicate that BIBDAV growth occurs at 30°C but is inhibited at 37°C, implying that crossing of the species barrier would be hindered by the body temperature of mammalian species.

scholarly journals Evaluation of the cobas Cdiff Test for Detection of Toxigenic Clostridium difficile in Stool Samples

2017 ◽  
Vol 55 (12) ◽  
pp. 3426-3436 ◽  
Author(s):  
Lance R. Peterson ◽  
Stephen A. Young ◽  
Thomas E. Davis ◽  
Zi-Xuam Wang ◽  
John Duncan ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
False Negative ◽  
Reference Method ◽  
Culture Method ◽  
Nucleic Acid Amplification ◽  
Culture Methods ◽  
Content Type ◽  
Toxigenic Culture ◽  
Discrepancy Analysis ◽  
Stool Samples

ABSTRACTNucleic acid amplification tests (NAATs) are reliable tools for the detection of toxigenicClostridium difficilefrom unformed (liquid or soft) stool samples. The objective of this study was to evaluate performance of the cobas Cdiff test on the cobas 4800 system using prospectively collected stool specimens from patients suspected of havingC. difficileinfection (CDI). The performance of the cobas Cdiff test was compared to the results of combined direct and broth-enriched toxigenic culture methods in a large, multicenter clinical trial. Additional discrepancy analysis was performed by using the XpertC. difficileEpi test. Sample storage was evaluated by using contrived and fresh samples before and after storage at −20°C. Testing was performed on samples from 683 subjects (306 males and 377 females); 113 (16.5%) of 683 subjects were positive for toxigenicC. difficileby direct toxigenic culture, and 141 of 682 subjects were positive by using the combined direct and enriched toxigenic culture method (reference method), for a prevalence rate of 20.7%. The sensitivity and specificity of the cobas Cdiff test compared to the combined direct and enriched culture method were 92.9% (131/141; 95% confidence interval [CI], 87.4% to 96.1%) and 98.7% (534/541; 95% CI, 97.4% to 99.4%), respectively. Discrepancy analysis using results for retested samples from a second NAAT (Xpert C. difficile/Epi test; Cepheid, Sunnyvale, CA) found no false-negative and 4 false-positive cobas Cdiff test results. There was no difference in positive and negative results in comparisons of fresh and stored samples. These results support the use of the cobas Cdiff test as a robust aid in the diagnosis of CDI.

scholarly journals Bartonella Infection among Cats Adopted from a San Francisco Shelter, Revisited

2015 ◽  
Vol 81 (18) ◽  
pp. 6446-6450 ◽  
Author(s):  
Drew A. Fleischman ◽  
Bruno B. Chomel ◽  
Rickie W. Kasten ◽  
Matthew J. Stuckey ◽  
Jennifer Scarlet ◽  
...  
Keyword(s):  
Young Adults ◽  
Young Adult ◽  
San Francisco ◽  
Bartonella Henselae ◽  
Bacterial Load ◽  
Culture Methods ◽  
Genotype I ◽  
Content Type ◽  
Culture Techniques ◽  
Culture Positive

ABSTRACTBartonellainfection among cats from shelters can pose a health risk to adopters.Bartonella henselaeis the most common species, withB. clarridgeiaeandB. koehleraebeing less common. The lower rates of infection by the latter species may reflect their rarity or an inefficiency of culture techniques. To assess the incidence of infection, blood cultures, serology, and PCR testing were performed on 193 kittens (6 to 17 weeks old) and 158 young adult cats (5 to 12 months old) from a modern regional shelter. ClassicalB. henselaeculture medium was compared to a medium supplemented with insect cell growth factors.Bartonellacolonies were isolated from 115 (32.8%) animals, including 50 (25.9%) kittens and 65 (41.1%) young adults. Therefore, young adults were twice as likely to be culture positive as kittens. Enhanced culture methods did not improve either the isolation rate or species profile.B. henselaewas isolated from 40 kittens and 55 young adults, whileB. clarridgeiaewas cultured from 10 animals in each group.B. koehleraewas detected in one young adult by PCR only.B. henselaegenotype II was more commonly isolated from young adults, and genotype I was more frequently isolated from kittens. Kittens were 4.7 times more likely to have a very high bacterial load than young adults. A significantly higher incidence of bacteremia in the fall and winter than in the spring and summer was observed.Bartonellaantibodies were detected in 10% (19/193) of kittens and 46.2% (73/158) of young adults, with culture-positive kittens being 9.4 times more likely to be seronegative than young adults.

scholarly journals The Serratia marcescens Siderophore Serratiochelin Is Necessary for Full Virulence during Bloodstream Infection

2020 ◽  
Vol 88 (8) ◽  
Author(s):  
Danelle R. Weakland ◽  
Sara N. Smith ◽  
Bailey Bell ◽  
Ashootosh Tripathi ◽  
Harry L. T. Mobley
Keyword(s):  
Serratia Marcescens ◽  
Bloodstream Infection ◽  
Iron Acquisition ◽  
Gene Clusters ◽  
Clinical Isolates ◽  
Wild Type ◽  
Serratia Plymuthica ◽  
Content Type ◽  
Cas Assay ◽  
Essential Nutrient

ABSTRACT Serratia marcescens is a bacterium frequently found in the environment, but over the last several decades it has evolved into a concerning clinical pathogen, causing fatal bacteremia. To establish such infections, pathogens require specific nutrients; one very limited but essential nutrient is iron. We sought to characterize the iron acquisition systems in S. marcescens isolate UMH9, which was recovered from a clinical bloodstream infection. Using RNA sequencing (RNA-seq), we identified two predicted siderophore gene clusters (cbs and sch) that were regulated by iron. Mutants were constructed to delete each iron acquisition locus individually and in conjunction, generating both single and double mutants for the putative siderophore systems. Mutants lacking the sch gene cluster lost their iron-chelating ability as quantified by the chrome azurol S (CAS) assay, whereas the cbs mutant retained wild-type activity. Mass spectrometry-based analysis identified the chelating siderophore to be serratiochelin, a siderophore previously identified in Serratia plymuthica. Serratiochelin-producing mutants also displayed a decreased growth rate under iron-limited conditions created by dipyridyl added to LB medium. Additionally, mutants lacking serratiochelin were significantly outcompeted during cochallenge with wild-type UMH9 in the kidneys and spleen after inoculation via the tail vein in a bacteremia mouse model. This result was further confirmed by an independent challenge, suggesting that serratiochelin is required for full S. marcescens pathogenesis in the bloodstream. Nine other clinical isolates have at least 90% protein identity to the UMH9 serratiochelin system; therefore, our results are broadly applicable to emerging clinical isolates of S. marcescens causing bacteremia.

scholarly journals Isolation of Mycobacterium avium Subsp. Paratuberculosis in the Feces and Tissue of Small Ruminants Using a Non-Automated Liquid Culture Method

Animals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20
Author(s):  
Luigi De Grossi ◽  
Davide Santori ◽  
Antonino Barone ◽  
Silvia Abbruzzese ◽  
Matteo Ricchi ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Liquid Culture ◽  
Culture Media ◽  
Small Ruminants ◽  
Culture Method ◽  
Mycobacterium Avium Subsp ◽  
Type I ◽  
Culture Methods ◽  
Specific Pcr ◽  
Mycobacterium Avium Subsp Paratuberculosis

Paratuberculosis is a chronic disease of ruminants caused by Mycobacterium avium subsp. Paratuberculosis (MAP). Since isolation of MAP type I (S) is rarely reported in Italy, our research was aimed at isolating, by an inexpensive liquid culture manual method, this type of MAP isolates. At first, we used an ELISA to point out to serologically positive samples from five flocks. Secondly, we used a fecal direct IS900-qPCR on the ELISA positive samples, in order to detect shedder animals. Feces from IS900-qPCR positive samples were inoculated in solid and liquid culture media. IS900-qPCR was further used to test the growth of MAP isolates in liquid medium, which were further confirmed by f57-qPCR and submitted to typing by specific PCR in order to identify the MAP type. Twenty-eight samples (24 fecal and four tissutal samples) were processed by culture methods, resulting in the isolation of six type I MAP field isolates. Notably, no isolates were recovered by solid media, underlining the utility of this liquid method. Few data about this type of MAP are currently available in Italy, and further analyses should be carried out in order to study the origin and epidemiology of type I strains circulating in Italy.

scholarly journals Updated and Validated Pan-Coronavirus PCR Assay to Detect All Coronavirus Genera

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 599
Author(s):  
Myndi G. Holbrook ◽  
Simon J. Anthony ◽  
Isamara Navarrete-Macias ◽  
Theo Bestebroer ◽  
Vincent J. Munster ◽  
...  
Keyword(s):  
Host Species ◽  
High Sensitivity ◽  
Respiratory Illness ◽  
Reservoir Host ◽  
Pcr Assay ◽  
Wildlife Reservoirs ◽  
Viral Surveillance ◽  
Reservoir Hosts

Coronavirus (CoV) spillover events from wildlife reservoirs can result in mild to severe human respiratory illness. These spillover events underlie the importance of detecting known and novel CoVs circulating in reservoir host species and determining CoV prevalence and distribution, allowing improved prediction of spillover events or where a human–reservoir interface should be closely monitored. To increase the likelihood of detecting all circulating genera and strains, we have modified primers published by Watanabe et al. in 2010 to generate a semi-nested pan-CoV PCR assay. Representatives from the four coronavirus genera (α-CoVs, β-CoVs, γ-CoVs and δ-CoVs) were tested and all of the in-house CoVs were detected using this assay. After comparing both assays, we found that the updated assay reliably detected viruses in all genera of CoVs with high sensitivity, whereas the sensitivity of the original assay was lower. Our updated PCR assay is an important tool to detect, monitor and track CoVs to enhance viral surveillance in reservoir hosts.

scholarly journals Genes Required for Aerial Growth, Cell Division, and Chromosome Segregation Are Targets of WhiA before Sporulation in Streptomyces venezuelae

mBio ◽  
2013 ◽  
Vol 4 (5) ◽  
Author(s):  
Matthew J. Bush ◽  
Maureen J. Bibb ◽  
Govind Chandra ◽  
Kim C. Findlay ◽  
Mark J. Buttner
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Regulatory Networks ◽  
Liquid Culture ◽  
Biological Processes ◽  
Streptomyces Venezuelae ◽  
Content Type ◽  
Master Regulators ◽  
Aerial Growth ◽  
Genes Encoding

ABSTRACTWhiA is a highly unusual transcriptional regulator related to a family of eukaryotic homing endonucleases. WhiA is required for sporulation in the filamentous bacteriumStreptomyces, but WhiA homologues of unknown function are also found throughout the Gram-positive bacteria. To better understand the role of WhiA inStreptomycesdevelopment and its function as a transcription factor, we identified the WhiA regulon through a combination of chromatin immunoprecipitation-sequencing (ChIP-seq) and microarray transcriptional profiling, exploiting a new model organism for the genus,Streptomyces venezuelae, which sporulates in liquid culture. The regulon encompasses ~240 transcription units, and WhiA appears to function almost equally as an activator and as a repressor. Bioinformatic analysis of the upstream regions of the complete regulon, combined with DNase I footprinting, identified a short but highly conserved asymmetric sequence, GACAC, associated with the majority of WhiA targets. Construction of a null mutant showed thatwhiAis required for the initiation of sporulation septation and chromosome segregation inS. venezuelae, and several genes encoding key proteins of theStreptomycescell division machinery, such asftsZ,ftsW, andftsK, were found to be directly activated by WhiA during development. Several other genes encoding proteins with important roles in development were also identified as WhiA targets, including the sporulation-specific sigma factor σWhiGand the diguanylate cyclase CdgB. Cell division is tightly coordinated with the orderly arrest of apical growth in the sporogenic cell, andfilP, encoding a key component of the polarisome that directs apical growth, is a direct target for WhiA-mediated repression during sporulation.IMPORTANCESince the initial identification of the genetic loci required forStreptomycesdevelopment, all of thebldandwhidevelopmental master regulators have been cloned and characterized, and significant progress has been made toward understanding the cell biological processes that drive morphogenesis. A major challenge now is to connect the cell biological processes and the developmental master regulators by dissecting the regulatory networks that link the two. Studies of these regulatory networks have been greatly facilitated by the recent introduction ofStreptomyces venezuelaeas a new model system for the genus, a species that sporulates in liquid culture. Taking advantage ofS. venezuelae, we have characterized the regulon of genes directly under the control of one of these master regulators, WhiA. Our results implicate WhiA in the direct regulation of key steps in sporulation, including the cessation of aerial growth, the initiation of cell division, and chromosome segregation.

scholarly journals Evaluation of the Carba NP Test for Rapid Detection of Carbapenemase-Producing Enterobacteriaceae and Pseudomonas aeruginosa

2013 ◽  
Vol 57 (9) ◽  
pp. 4578-4580 ◽  
Author(s):  
Nathalie Tijet ◽  
David Boyd ◽  
Samir N. Patel ◽  
Michael R. Mulvey ◽  
Roberto G. Melano
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Rapid Detection ◽  
False Negative ◽  
Bacterial Extract ◽  
Content Type ◽  
Negative Results ◽  
False Negative Results

ABSTRACTThe Carba NP test was evaluated against a panel of 244 carbapenemase- and non-carbapenemase-producingEnterobacteriaceaeandPseudomonas aeruginosaisolates. We confirmed the 100% specificity and positive predictive value of the test, but the sensitivity and negative predictive value were 72.5% and 69.2%, respectively, and increased to 80% and 77.3%, respectively, using a more concentrated bacterial extract. False-negative results were associated with mucoid strains or linked to enzymes with low carbapenemase activity, particularly OXA-48-like, which has emerged globally in enterobacteria.

scholarly journals Evaluation of Recombinant Proteins of Burkholderia mallei for Serodiagnosis of Glanders

2012 ◽  
Vol 19 (8) ◽  
pp. 1193-1198 ◽  
Author(s):  
Vijai Pal ◽  
Subodh Kumar ◽  
Praveen Malik ◽  
Ganga Prasad Rai
Keyword(s):  
Sensitivity And Specificity ◽  
Recombinant Proteins ◽  
False Negative ◽  
Enzyme Linked Immunosorbent Assay ◽  
Burkholderia Mallei ◽  
Content Type ◽  
Whole Cells ◽  
Negative Results ◽  
Elisa Format ◽  
Low Sensitivity

ABSTRACTGlanders is a contagious disease caused by the Gram-negative bacillusBurkholderia mallei. The number of equine glanders outbreaks has increased steadily during the last decade. The disease must be reported to the Office International des Epizooties, Paris, France. Glanders serodiagnosis is hampered by the considerable number of false positives and negatives of the internationally prescribed tests. The major problem leading to the low sensitivity and specificity of the complement fixation test (CFT) and enzyme-linked immunosorbent assay (ELISA) has been linked to the test antigens currently used, i.e., crude preparations of whole cells. False-positive results obtained from other diagnostic tests utilizing crude antigens lead to financial losses to animal owners, and false-negative results can turn a risk into a possible threat. In this study, we report on the identification of diagnostic targets using bioinformatics tools for serodiagnosis of glanders. The identified gene sequences were cloned and expressed as recombinant proteins. The purified recombinant proteins ofB. malleiwere used in an indirect ELISA format for serodiagnosis of glanders. Two recombinant proteins, 0375H and 0375TH, exhibited 100% sensitivity and specificity for glanders diagnosis. The proteins also did not cross-react with sera from patients with the closely related disease melioidosis. The results of this investigation highlight the potential of recombinant 0375H and 0375TH proteins in specific and sensitive diagnosis of glanders.

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