Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Rhodococcus equi”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources
PubMed1995

[Nosocomial infections: new agents, incidence, prevention].

Nosocomial infection is one of the major health problems confronting clinicians in intensive care units. Incidence has been estimated to vary from 5 to 10%, leading to death in one of every 5000 persons hospitalized. This situation is not however static since hospital epidemics and nosocomial infections evolve as a consequence of advances in antibiotic drug therapy and surgical and intensive care techniques. Microbial investigations themselves are of major importance as the collection of epidemiological data and its communication to hospital partners affects their approach to patient management. Nosocomial pneumonia, particularly in ventilated patients, urinary infection in those with indwelling catheters and wound colonization after surgery are still major problems and explain part of the variations between wards and hospitals. The main changes concern the bacteria involved. Classical agents with new mechanisms of resistance (Klebsiella pneumoniae, extended spectrum beta-lactamase producers) have been joined by other "new" agents emerging as pathogens (Xanthomonas maltophilia, Acinetobacter baumannii). The incidence of resistance in Staphylococcus and Enterococcus strains as well as new Gram positive species including Corynebacterium jeikeium and Rhodococcus equi, now recognized as opportunistic agents, has also increased. The multiresistance of these pathogens is often responsible for failure of antibiotic therapy and emphasizes the need both for rigorous prevention through active cooperation between bacteriologists, ward clinicians and intensive care units, and further research in the fields of microbial resistance mechanisms and antibiotics. Preventive measures have become a priority creating an international challenge to health care policy makers.

Cross Infection↗
PubMed1994

[New macrolides].

The macrolides are still widely used in general practice and the new 14- or 15 membered-ring compounds-roxithromycin, clarithromycin, dirithromycin, azithromycin -may offer a new development. Their antibacterial activity is similar to erythromycin but azithromycin is more active against Gram negative strams. Roxythromycin exhibits high serum concentrations; azithromycin and dirithromycin present low serum concentrations but prolonged half-lives allowing a reduction of the duration of treatment particularly for pharyngitis (azithromycin). Macrolides are less useful for otitis and sinusitis treatment since their activity against H. influenzae and S. pneumoniae are weak. The activity against atypical bacteria justify their choice as first line treatment for benign atypical pneumonia of healthy young adults and for sexually transmitted diseases. In AIDS, these compounds are indicated in mycobacteriosis (clarithromycin), bacillary angiomatosis and excavated pneumonia due to Rhodococcus equi. Clinical tolerance is very good, particularly the gastro-intestinal one. The reported drug interactions are those of this class of antibiotics.

Anti-Bacterial Agents↗
PubMed1993

Bacterial pneumonia in HIV-infected patients.

Individuals infected with the human immunodeficiency virus (HIV) are more susceptible to bacterial infections because of defects in both cellular and humoral immunity. Streptococcus pneumoniae and Haemophilus influenzae are the most common causes of bacterial pneumonia in HIV-infected patients. However, more unusual bacteria can also cause pneumonia. Response to therapy is generally good for infections caused by pyogenic organisms, and complications are relatively few. Unfortunately, infections caused by Rhodococcus equi and Nocardia species are associated with significant morbidity and mortality. Moreover, the duration of therapy is long, and relapes are common. Prevention of bacterial pneumonia is an important part of the care of HIV-infected patients; the 23 valent pneumococcal vaccine is currently recommended for all HIV-infected patients. The role of other preventative measures remains unknown.

Adult↗
PubMed1997

[Meropenem: microbiologic perspective].

Meropenem is a beta-lactamic carbapenem derived from thienamycin and is structurally characterized by the presence of a beta-methyl group in position C1 which confers stability to the molecule versus renal dehydropeptidase 1 (DHP-1), thereby making the coadministration of an enzyme inhibitor unnecessary. Its esterochemical configuration of the lateral chain in C2 (dimethyl carbomoilpyrrolidenethium) increases the activity versus gram negative bacteria (enterobacteria and pseudomonas) and moreover, may explain the reduction in the proconvulsive effect observed in imipenem/cilastatin. Meropenem has great bactericide power and has a very wide spectrum of activity depending on it low molecular weight and zwiterionic structure, stability versus almost all the clinically important beta-lactamases and high affinity for the PBPs. It covers gram positive aerobes (Staphylococcus aureus, coagulase negative staphylococci, streptococci including Streptococcus pneumoniae resistant to penicillin, Enterococcus faecalis, Rhodococcus equi, Listeria monocytogenes) and gram negative bacteria (enterobacteria, P. aeruginosa, Acinetobacter, Aeromonas, Plesiomonas, Vibrio, Haemophilus influenzae, Neisseria, Moraxella) and anaerobes (Bacteroides, Prevotella, Porphyromonas, Fusobacterium, Clostridium, Peptostreptococcus, and Propionibacterium acnes), being more active than imipenem versus gram negatives: P. aeruginosa (2-4-fold), enterobacteria (2-32-fold) and H. influenzae (4-8-fold) and less active versus the gram positives (enterococci, streptococci and staphylococci). Meropenem has no activity on Enterococcus faecium, S. aureus resistant to methycillin, Stenotrophomonas maltophilia and other genera producers of chromosomic methalo-beta-lactamases (carbapenemases). Resistance may be due to impermeability given the loss of the OprD porin (OprD2 in enterobacteria and P. aeruginosa) loss of different membrane proteins (Proteus mirabilis, Proteus rettgeri, Enterobacter cloacae, Enterobacter aerogenes), modifications of the PBPs (gram positive) and the production of carbapenemases (chromosomic methalo-beta-lactamases).

Bacteria, Aerobic↗
PubMedDate not supplied

[Bacteriological and clinical aspects of corynebacterium].

The microbiologists use the term corynebacteria to describe aerobically growing, asporogenous, irregularly sharped gram-positive rods. They comprise strictly aerobic bacteria isolated from environment as well as preferentially anaerobic bacteria found in clinical specimens. A large part of these bacteria is considered as commensal of skin and mucous membranes. This group of organisms has recently been subjected to considerable taxonomic revisions, which have resulted in the proposal of several new species, many of them representing previous Centers for Diseases Control coryneform groups. Moreover, recent investigations demonstrated the existence of a pathogenic role for some of them. These bacteria comprise well-known pathogens such as C. diphtheriae responsible for diphtheria, Actinomyces spp. responsible for actinomycosis and Arcanobacterium haemolyticum recovered from pharyngitis, but other corynebacteria were related to particular infections. For example, the lipophilic and antibiotics multiresistant species Corynebacterium urealyticum and C. jeikeium were found to be responsible for urinary tract infections and septicemias, respectively. The recently described species Turicella otitidis was found to be implicated in otitis media and C. seminale were recovered from genital specimens of male patients. Implantation of material devices, use of broad-spectrum antibiotics led to an increase of sepsis due to the species C. jeikeium and C. amycolatum. Many of the new Actinomyces species grow well under aerobic conditions and are often implicated in various abscesses. Moreover an increase of immunocompromised patients led to the development of infections due to the aerobic actinomycete Rhodococcus equi. The association of some corynebacteria with particular diseases should prompt the microbiologist to identify these bacteria when they are encountered in a pathogenic situation. Identification of the major part of corynebacteria isolated from clinical specimens can now be achieved by using recent schemes.

Anaerobiosis↗
PubMed1998

[Pulmonary cavitation lesions in patients infected with the human immunodeficiency virus: an analysis of a series of 78 cases].

BACKGROUND: To assess the clinical, radiologic and microbiological features of lung cavitation and HIV infection. Evaluation of the differences related to this disease in the last years. PATIENTS AND METHODS: Retrospective review of all patients with lung cavitation and HIV infection admitted at our hospital from January 1989 until December 1994 and prospective study of all patients with the same characteristics during 1995 and 1996. Lung cavitation was defined as any parenchymal lesion, with air content, visible in a simple X-ray and greater than 1 cm of diameter. Criteria for confirmed, probable or possible diagnosis were defined. RESULTS: 78 cases of lung cavitation have been identified in 73 patients. The radiologic patterns included unilobar and multilobular involvement in 31 and 47 cases, respectively. Cavities were multiple and single in 40 and 38 cases respectively. Findings with fine needle aspiration biopsy (FNAB) were diagnostic in 11 out of 14 cases. A clinical diagnosis was performed in all 78 cases, with microbiological results in 69 cases (88.5%): Mycobacterium tuberculosis in 20, Pneumocystis carinii in nine, Pseudomonas aeruginosa in nine, Staphylococcus aureus in eight (5 endocarditis with cavitary septic emboli), Rhodococcus equi in six, P. aeruginosa and S. aureus in three, Salmonella enteritidis in three, Cryptococcus neoformans in two, Aspergillus fumigatus in two and others in 7 cases. Confirmed, probable and possible diagnosis was considered in 54, 15 and 9 cases, respectively. Thirteen episodes of spontaneous pneumothorax were found. CONCLUSIONS: The lung cavitation rate is low, compared with the number of admissions related to HIV infection; nevertheless, many of them are in close relationship with HIV infection, and most of them are caused by treatable infections. It is important to know the clinical and radiological characteristics, in order to establish an early diagnosis and an appropriate therapy. Pseudomonas aeruginosa is becoming an important cause of lung cavitation. In our series, spontaneous pneumo-thorax was not related to Pneumocystis carinii pneumonia in 61.5% of cases.

AIDS-Related Opportunistic Infections↗
PubMed1993

Novel mechanism for the CAMP reaction between Listeria monocytogenes and Corynebacterium equi.

The synergistic hemolytic reaction between Listeria monocytogenes, Staphylococcus aureus and Corynebacterium equi on blood agar plates was explored using a modified test-tube assay. A synergistic lysis of sheep red blood cells was observed with L. monocytogenes and either S. aureus or C. equi, using crude extracts. Synergism was also found with L. monocytogenes and purified cholesterol oxidase from Pseudomonas fluorescens and Brevibacterium brevi. Crude extracts of S. aureus sensitized sheep red blood cells to subsequent lysis with either L. monocytogenes or C. equi. The interaction between L. monocytogenes and C. equi apparently did not involve a pre-sensitization step; simultaneous exposure of sheep red blood cells to the two extracts was required. A number of strains of L. monocytogenes gave positive synergistic reactions with cholesterol oxidase, suggesting that this reaction may be more useful than the CAMP test with C. equi for identifying L. monocytogenes. These results suggest that a novel synergistic reaction may be taking place, possibly involving the listeriolysin O, or one or both of the phospholipases from L. monocytogenes.

Animals↗
PubMed1990

Revision of the validity of CAMP tests for Listeria identification. Proposal of an alternative method for the determination of haemolytic activity by Listeria strains.

The validity of CAMP tests with Staphylococcus aureus and Rhodococcus (Corynebacterium) equi as defined for Listeria identification was revised. This characterization method appeared to be unreliable for two reasons: first, a positive CAMP test with R. equi is not specific for Listeria ivanovii as Listeria monocytogenes (and Listeria seeligeri) give also a clear positive reaction; second, doubtful reactions could be observed with S. aureus when assaying haemolytic and non-haemolytic Listeria strains (possibility of false negative and false positive results; subjectivity of the interpretation). The use of a Microplate technique previously described instead of CAMP tests is proposed for the reliable demonstration of the haemolytic character of Listeria in the routine identification of these organisms.

Bacterial Typing Techniques↗
PubMed2000

Evaluation of mini-VIDAS rapid test for detection of Listeria monocytogenes from production lines of fresh to cold-smoked fish.

This study was conducted to evaluate the efficacy of the mini-VIDAS Listeria monocytogenes (LMO) system (BioMérieux Vitek, Inc., Missouri, USA) for detection of L. monocytogenes in environmental and fish samples from three Portuguese cold-smoking plants and from their fresh fish suppliers. Mini-VIDAS-LMO is a fully automated system that uses fluorescent ELFA (Enzyme Linked Fluorescent Assay) technology for detection of Listeria monocytogenes antigens in food. It can be a rapid screening method alternative to time consuming classical isolation and identification. Two hundred and ninety five samples were tested in mini-VIDAS-LMO and in parallel by the ISO 11290-1 traditional protocol. The mini-VIDAS-LMO detected 8 of the 11 confirmed positive samples and presented 11 false positive results. The specificity of the mini-VIDAS-LMO found in this experiment was 0.96 and the sensitivity 0.73.

Animals↗
PubMed1999

Diversity of bacterial strains degrading hexadecane in relation to the mode of substrate uptake.

The relative distribution of the modes of hydrocarbon uptake, used by bacteria of the environment for the degradation of long-chain alkanes, has been evaluated. The first mode of uptake, direct interfacial accession, involves contact of cells with hydrocarbon droplets. In the second mode, biosurfactant-mediated transfer, cell contact takes place with hydrocarbons emulsified or solubilized by biosurfactants. Sixty-one strains growing on hexadecane were isolated from polluted and non-polluted soils and identified. The majority (61%) belonged to the Corynebacterium-Mycobacterium-Nocardia group. Criteria selected for characterizing hexadecane uptake were cell hydrophobicity, interfacial and surface tensions and production of glycolipidic extracellular biosurfactants. These properties were determined in flask cultures on an insoluble (hexadecane) and on a soluble (glycerol or succinate) carbon source for a subset of 23 representative strains. Exclusive direct interfacial uptake was utilized by 47% of studied strains. A large proportion of strains (53%) produced biosurfactants. The data on cellular hydrophobicity suggested the existence of two distinct alkane transfer mechanisms in this group. Accordingly, tentative assignments of biosurfactant-mediated micellar transfer were made for 11% of the isolated strains, and of biosurfactant-enhanced interfacial uptake for 42%.

Alkanes↗
PubMed1997

Detection of orbital implant infection with technetium 99m-labeled leukocytes.

Orbital implant infection is a rare cause of anophthalmic socket pain. Because of the potential danger of infection spreading to nearby structures, it is of paramount importance to diagnose the condition as soon as possible. Scintigraphy is a method for diagnosis of graft infections by radioisotopic imaging of inflammatory sites. We report on a patient with socket pain 3 months after implantation of an acrylic implant. The socket appearance was normal and there were no signs of infection other than culture-positive socket exudation. Three consecutive computed tomography scans revealed no abnormalities. 99mTc leukocyte scintigraphy revealed white blood cell accumulation at the implantation site. The implant was removed and cultured. This produced Staphylococcus epidermidis and R. equii. A parenteral antibiotic treatment was instituted with subsequent improvement of symptoms. Four months later, after negative scintigraphy, a hydroxyapatite implant was inserted, demonstrating full vascularization on a bone scan after 2 months. Two months later, the patient developed the previous symptoms, with all of the former findings, including positive scintigraphy. The implant was removed, revealing a microabscess on the anterior aspect, producing S. epidermidis on culture. We conclude that scintigraphy using 99mTc-labeled leukocytes is a useful technique in diagnosing low-grade orbital infection.

Acrylic Resins↗
PubMed1980

The distribution of Mycobacterium bovis in Queensland cattle herds with observations on the laboratory diagnosis of tuberculosis.

Of 1,791 tissues submitted from 1975 to 1978 for histological examination for tuberculosis, 78.5% were classified as tuberculosis, 8.1% as club-forming granulomas, 3.3% as hydatid cysts, 3.4% as other granulomas and 2.4% as squamous cell carcinomas. Cultural examination of 2,682 tissues for mycobacteria yielded Mycobacterium bovis from 42.88%, other mycobacteria from 7.64% and 0.89% Rhodococcus (Corynebacterium) equi. Of 1,478 tissues on which both examinations were performed, culture and histology results were in agreement on 94.1%. M. Bovis was isolated on one or more occasions from 564 herds with the highest herd prevalence being recorded in western areas of the state. Culture of 1,024 tissues from no visible lesion (NVL) reactors yielded 0.59% M. bovis, 15.04% other mycobacteria and 0.19% R. equi. Of 120 isolates of other mycobacteria from tissues of NVL reactors, 39 were Runyon Group III (20 M.avium complex) and 61 Runyon Group IV. Approximately half of the herds from which NVL tissues were collected were confirmed M. bovis infected properties.

Actinobacillosis↗