-
Diseases of Aquatic Organisms Aug 2006Renibacterium salmoninarum causes bacterial kidney disease (BKD), a chronic and sometimes fatal disease of salmon and trout that could lower fitness in populations with... (Comparative Study)
Comparative Study
Renibacterium salmoninarum causes bacterial kidney disease (BKD), a chronic and sometimes fatal disease of salmon and trout that could lower fitness in populations with high prevalences of infection. Prevalence of R. salmoninarum infection among juvenile Chinook salmon Oncorhynchus tshawytscha inhabiting neritic marine habitats in North Puget Sound, Washington, USA, was assessed in 2002 and 2003. Fish were collected by monthly surface trawl at 32 sites within 4 bays, and kidney infections were detected by a quantitative fluorescent antibody technique (qFAT). The sensitivity of the qFAT was within an order of magnitude of the quantitative real-time PCR (qPCR) sensitivity. Prevalence of infection was classified by fish origin (marked/hatchery vs. unmarked/likely natural spawn), month of capture, capture location and stock origin. The highest percentages of infected fish (63.5 to 63.8%) and the greatest infection severity were observed for fish collected in Bellingham Bay. The lowest percentages were found in Skagit Bay (11.4 to 13.5%); however, there was no difference in prevalence between marked and unmarked fish among the capture locations. The optimal logistic regression model of infection probabilities identified the capture location of Bellingham Bay as the strongest effect, and analysis of coded wire tagged (CWT) fish revealed that prevalence of infection was associated with the capture location and not with the originating stock. These results suggest that infections can occur during the early marine life stages of Chinook salmon that may be due to common reservoirs of infection or horizontal transmission among fish stocks.
Topics: Actinomycetales Infections; Animals; Bacteriological Techniques; Fish Diseases; Geography; Kidney Diseases; Micrococcaceae; Models, Statistical; Prevalence; Salmon; Sodium Chloride; Temperature; Time Factors; Washington
PubMed: 17058599
DOI: 10.3354/dao071179 -
Journal of Clinical Microbiology Jul 1996Oerskovia spp. are gram-positive, Nocardia-like bacilli which inhabit the soil and rarely cause human infections. Previously reported cases of Oerskovia infection have... (Review)
Review
Oerskovia spp. are gram-positive, Nocardia-like bacilli which inhabit the soil and rarely cause human infections. Previously reported cases of Oerskovia infection have been characterized by a nonaggressive course and an association with foreign bodies. We report the first case of a patient with a prosthetic joint infection due to Oerskovia xanthineolytica. Our patient presented with a prolonged, indolent course and was thought to have aseptic loosening of his prosthesis until the time of surgery. He was cured of his infection by removal of the prosthesis, antibiotic therapy, and delayed reimplantation. Review of the previous 10 reported cases of Oerskovia infection in humans supports the recommendation that foreign-body-associated infections should be treated with a strategy that includes removal of the foreign material.
Topics: Actinomycetales; Actinomycetales Infections; Aged; Anti-Bacterial Agents; Drug Therapy, Combination; Humans; Knee Prosthesis; Male; Prosthesis-Related Infections; Reoperation
PubMed: 8784601
DOI: 10.1128/JCM.34.7.1821-1824.1996 -
Pneumonologia I Alergologia Polska 2007Malakoplakia is a rare, chronic, granulomatous disease seen in immunocompromised patients, caused by multiple infectious agents, most often bacteria. Microscopically,... (Review)
Review
Malakoplakia is a rare, chronic, granulomatous disease seen in immunocompromised patients, caused by multiple infectious agents, most often bacteria. Microscopically, accumulations of macrophages with granular cytoplasm and intra- or extracellular structures, called Michaelis-Gutmann bodies are characteristic. Main cause of pulmonary malakoplakia is Rhodococcus equi infection. We report two cases of pulmonary malakoplakia, in one case R. equi infection was confirmed. We also present a summary of recent knowledge about the pathogenesis, morphology and clinical course of the disease.
Topics: AIDS-Related Opportunistic Infections; Actinomycetales Infections; Adult; Humans; Immunocompromised Host; Lung Diseases; Malacoplakia; Male; Prognosis; Rhodococcus equi; Risk Factors
PubMed: 18080992
DOI: No ID Found -
The Journal of Veterinary Medical... Feb 2020Trueperella pyogenes is an opportunistic pathogen that causes a wide variety of purulent infections. We recently isolated a T. pyogenes strain unable to be identified by...
Trueperella pyogenes is an opportunistic pathogen that causes a wide variety of purulent infections. We recently isolated a T. pyogenes strain unable to be identified by the previously reported T. pyogenes pyolysin gene (plo)-specific PCR from the lung of a sheep with astasia. Sequence comparison of plo among representative strains revealed several nucleotide substitutions in the primer-annealing regions. As such substitutions were considered to be a reason for the low PCR specificity, we designed novel primers in conserved regions of plo. Under optimized conditions, the novel primers precisely identified all T. pyogenes strains tested, and no products were generated from any other bacterial strains, suggesting the usefulness of the novel PCR assay for the diagnosis of T. pyogenes infections.
Topics: Actinomycetaceae; Actinomycetales Infections; Animals; Bacterial Proteins; Bacterial Toxins; Hemolysin Proteins; Lung; Polymerase Chain Reaction; Sheep; Sheep Diseases
PubMed: 31866633
DOI: 10.1292/jvms.19-0522 -
The Journal of Veterinary Medical... Mar 2017The main factors affecting the outcome of Trueperella pyogenes (T. pyogenes) mastitis were examined through a survey of diagnostic data and interviews relating to the...
The main factors affecting the outcome of Trueperella pyogenes (T. pyogenes) mastitis were examined through a survey of diagnostic data and interviews relating to the occurrence of T. pyogenes mastitis in 83 quarters from 82 Holstein cows between August 2012 and April 2014. Ultimately, one cow was sold during the examination, and 82 quarters from 81 cows were used for analysis on prognosis. T. pyogenes mastitis occurred year round in both lactating and dry cows. The incidence of T. pyogenes mastitis did not significantly differ by month or show seasonality in either lactating or dry cows. Therefore, the occurrence of T. pyogenes mastitis also differed from that of summer mastitis. The 1-month survival rate of infected cows was 64.6% (53/82), and the recovery rate of quarters with T. pyogenes mastitis was 14.6% (12/82). Bivariate logistic regression analysis was performed with survival and culling of infected cows as objective variables and with recovery and non-recovery of quarters with T. pyogenes mastitis as objective variables. The severe cases were significantly culled (odds ratio, 16.30) compared to mild cases, and the status of quarters didn't recover (odds ratio, 6.50). The results suggest that mild to moderate symptom severity at the time of onset are the main factors affecting outcomes in cows and recovery of quarters infected with T. pyogenes mastitis. Further, high level of NAGase activity also suggested the potential use as an indicator of culling of cows with T. pyogenes mastitis.
Topics: Actinomycetaceae; Actinomycetales Infections; Animals; Cattle; Dairying; Female; Hexosaminidases; Incidence; Japan; Lactation; Mastitis, Bovine; Milk; Seasons
PubMed: 28163273
DOI: 10.1292/jvms.16-0401 -
Archives of Microbiology Mar 2023Trueperella pyogenes (T. pyogenes) is a zoonotic pathogen that is cause a variety of pyogenic diseases in animals. The complex pathogenicity and various virulence...
Trueperella pyogenes (T. pyogenes) is a zoonotic pathogen that is cause a variety of pyogenic diseases in animals. The complex pathogenicity and various virulence factors are important challenges to produce an effective vaccine. According to previous trials, inactivated whole-cell bacteria or recombinant vaccines were unsuccessful in preventing disease. Thus, this study aims to introduce a new vaccine candidate based on a live-attenuated platform. For this purpose, first T. pyogenes was subjected to sequential passage (SP) and antibiotic treatment (AT) to lose their pathogenicity. Second, Plo and fimA expressions as virulence genes were evaluated by qPCR and then mice were challenged with bacteria from SP and AT culture by intraperitoneal route. Compared to the control group (T. pyogenes-wild type), plo and fimA gene expressions were downregulated and vaccinated mice have a normal spleen appearance in contrast to the control group. In addition, there was no significant difference between bacterial count from spleen, liver, heart and peritoneal fluid in vaccinated mice and the control group. In conclusion, this study introduces a new T. pyogenes vaccine candidate based on a live-attenuated strategy that mimics natural infection without pathogenicity for further investigation on vaccines against T. pyogenes infections.
Topics: Animals; Mice; Actinomycetales Infections; Anti-Bacterial Agents; Virulence Factors; Virulence; Vaccine Development
PubMed: 36973450
DOI: 10.1007/s00203-023-03481-4 -
Journal of Clinical Microbiology Mar 2006We report the third case of endocarditis caused by the newly described micrococcal species Kytococcus schroeteri. A 49-year-old woman was admitted to the hospital with... (Review)
Review
We report the third case of endocarditis caused by the newly described micrococcal species Kytococcus schroeteri. A 49-year-old woman was admitted to the hospital with suspected prosthetic valve endocarditis. Five blood cultures and prosthetic valve cultures grew the same type of organism, initially identified as Micrococcus sp. Assignment to the genus Kytococcus was suggested by the arginine dihydrolase activity and resistance to oxacillin. After sequencing of the 16S rRNA genes, the isolate was recognized as K. schroeteri. The patient was treated first with vancomycin combined with gentamicin and later with pristinamycin and rifampin. Three cases of K. schroeteri endocarditis described within a short period of time might indicate a specific pathogenicity of this new species. The isolation of kytococci from normally sterile sites should not be overlooked.
Topics: Actinomycetales; Actinomycetales Infections; Base Sequence; DNA, Bacterial; DNA, Ribosomal; Endocarditis, Bacterial; Female; Genes, Bacterial; Heart Valve Prosthesis; Humans; Middle Aged; RNA, Bacterial; RNA, Ribosomal, 16S
PubMed: 16517928
DOI: 10.1128/JCM.44.3.1187-1189.2006 -
PloS One 2013Rhodococcus equi is a facultative intracellular pathogen of macrophages and the causative agent of foal pneumonia. R. equi virulence is usually assessed by analyzing...
Rhodococcus equi is a facultative intracellular pathogen of macrophages and the causative agent of foal pneumonia. R. equi virulence is usually assessed by analyzing intracellular growth in macrophages by enumeration of bacteria following cell lysis, which is time consuming and does not allow for a high throughput analysis. This paper describes the use of an impedance based real-time method to characterize proliferation of R. equi in macrophages, using virulent and attenuated strains lacking the vapA gene or virulence plasmid. Image analysis suggested that the time-dependent cell response profile (TCRP) is governed by cell size and roundness as well as cytoxicity of infecting R. equi strains. The amplitude and inflection point of the resulting TCRP were dependent on the multiplicity of infection as well as virulence of the infecting strain, thus distinguishing between virulent and attenuated strains.
Topics: Actinomycetales Infections; Animals; Cell Line; Electric Impedance; Horses; Host-Pathogen Interactions; Humans; Macrophages; Mice; Mutation; Rhodococcus equi
PubMed: 23555995
DOI: 10.1371/journal.pone.0060612 -
American Journal of Veterinary Research Aug 2001To determine whether purified equine immunoglobulin specific for Rhodococcus equi virulence-associated proteins A and C (VapA and VapC) can confer passive protection...
Evaluation of equine immunoglobulin specific for Rhodococcus equi virulence-associated proteins A and C for use in protecting foals against Rhodococcus equi-induced pneumonia.
OBJECTIVE
To determine whether purified equine immunoglobulin specific for Rhodococcus equi virulence-associated proteins A and C (VapA and VapC) can confer passive protection against R. equi-induced pneumonia in foals.
ANIMALS
Twenty-eight 3-week-old mixed-breed pony foals.
PROCEDURE
7 foals received IV injections of equine hyperimmune plasma (HIP) against whole-cell R. equi, and 7 received purified equine immunoglobulin specific for VapA and VapC 1 day prior to intrabronchial infection with R. equi strain 103+. Eleven foals were not treated prior to infection, and 3 control foals were neither treated nor infected. Heart rate, respiratory rate, and rectal temperature were recorded twice daily, and serum fibrinogen concentration and WBC count were determined every other day following infection. Foals were euthanatized 14 days following infection, and lung lesions and concentration of R. equi in lungs were assessed.
RESULTS
The onset of clinical signs of pneumonia was significantly delayed in the HIP- and immunoglobulin-treated groups, compared with the untreated infected group. Moreover, pulmonary lesions were less severe in the treated groups, and significantly fewer R. equi organisms were cultured from the lungs of treated foals.
CONCLUSIONS AND CLINICAL RELEVANCE
Degree of protection against R. equi-induced pneumonia provided by purified immunoglobulin specific for VapA and VapC was similar to that provided by commercially available HIP. Results not only suggest that immunoglobulin is the primary component of HIP that confers protection against R. equi-induced pneumonia in foals but also indicate that antibodies against R. equi VapA and VapC are protective.
Topics: Actinomycetales Infections; Animals; Antibodies, Bacterial; Antibody Specificity; Bacterial Proteins; Body Temperature; Fibrinogen; Heart Rate; Horse Diseases; Horses; Immunoglobulins; Leukocyte Count; Lipoproteins; Lung; Male; Membrane Glycoproteins; Pneumonia, Bacterial; Random Allocation; Recombinant Proteins; Respiration; Rhodococcus equi; Virulence Factors
PubMed: 11497456
DOI: 10.2460/ajvr.2001.62.1307 -
Journal of Veterinary Internal Medicine May 2022Intragastric administration of virulent Rhodococcus equi protects foals against subsequent experimental intrabronchial (IB) infection, but it is unknown whether R. equi...
BACKGROUND
Intragastric administration of virulent Rhodococcus equi protects foals against subsequent experimental intrabronchial (IB) infection, but it is unknown whether R. equi naturally ingested by foals contributes to their susceptibility to pneumonia.
HYPOTHESIS
Fecal concentration of virulent R. equi before IB infection with R. equi is positively associated with protection from pneumonia in foals.
ANIMALS
Twenty-one university-owned foals.
METHODS
Samples were collected from experimental studies. Five foals were gavaged with live, virulent R. equi (LVRE) at age 2 and 4 days; the remaining 16 foals were not gavaged with LVRE (controls). Fecal swabs were collected from foals at ages 28 days, immediately before IB infection. Foals were monitored for clinical signs of pneumonia, and fecal swabs were collected approximately 2 weeks after IB infection. Swabs were tested by quantitative PCR for concentration of virulent R. equi (ie, copy numbers of the virulence-associated protein A gene [vapA] per 100 ng fecal DNA).
RESULTS
Fecal concentrations of virulent R. equi (vapA) before IB infection were significantly (P < .05) lower in control foals (25 copies/100 ng DNA [95% CI, 5 to 118 copies/100 ng DNA) that developed pneumonia (n = 8) than in healthy control foals (n = 8; 280 copies/100 ng DNA; 95% CI, 30 to 2552 copies/100 ng DNA) or those gavaged with LVRE (707 copies/100 ng DNA, 95% CI, 54 to 9207 copies/100 ng DNA).
CONCLUSIONS AND CLINICAL IMPORTANCE
Greater natural ingestion of LVRE might contribute to protection against pneumonia among foals.
Topics: Actinomycetales Infections; Animals; Horse Diseases; Horses; Humans; Pneumonia; Rhodococcus equi
PubMed: 35322902
DOI: 10.1111/jvim.16409