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PubMed1976

The pathogenicity of Mycobacterium fortuitum and Mycobacterium chelonei in man: a report of seven cases.

The clinical records of 7 patients referred to the National Jewish Hospital and Research Center over a 6-year period for evaluation of an abnormal chest x-ray and repeated sputum isolates of rapidly growing mycobacteria (Runyon's Group IV) were reviewed to determine the potential pathogenicity of these organisms. Mycobacterium fortuitum was isolated from 5 patients and Mycobacterium chelonei from 2. Haemoptysis, cough and weight loss were prominent in 6. Three had rheumatoid arthritis. Although two demonstrated cutaneous anergy, lymphocyte responsiveness to PHA was normal. PPD-F was not useful in skin testing or in the in vitro evaluation of lymphocyte function. Histologic examination of the lungs of 2 patients demonstrated caseating granulomata. One patient died of massive pulmonary haemorrhage soon after intiation of therapy. Multi-drug treatment regimens generally resulted in progressive sterilization of the sutum and improvement in the appearance of the chest x-ray. We conclude that some rapidly growing mycobacteria can cause potentially fatal cavitary lung disease and that intensive anti-tuberculosis therapy may successfully alter its course.

Adult↗

PubMed1995

Burkholderia cepacia and cystic fibrosis: do natural environments present a potential hazard?

An environmental survey of 55 sites yielded only 12 Burkholderia cepacia isolates, none of which displayed the phenotypic properties of a multiresistant epidemic strain associated with pulmonary colonization in patients with cystic fibrosis. Although the environment probably poses a low risk for patients with cystic fibrosis as a source of B. cepacia, the pathogenic potential of individual environmental strains remains unclear. We advise caution in the development of B. cepacia as a biocontrol agent.

Burkholderia cepacia↗

PubMed1993

[Frequency of bronchopulmonary isolation of Aspergillus species in patients infected with human immunodeficiency virus: pathogenic role?].

Prevalence of aspergillosis in patients infected with the human immunodeficiency virus (HIV) is unknown. Mycologic findings in bronchopulmonary specimens from 614 HIV-positive patients sent to a parasitology laboratory between June 1, 1989 and May 31, 1991 were analyzed retrospectively; medical records of Aspergillus sp--positive patients were studied to evaluate the potential pathogenic role of this organism. Prevalence of Aspergillus sp. was 2.7% in bronchoalveolar lavage (BAL) specimens, (21/757), 15.1% in sputum specimens (3/53), 12.6% in bronchial aspirates (11/87), 7% in protected brush specimens (2/28), and 16.6% in lung biopsy specimens (4/24). A total of 20 patients (rate = 3.14%) had lung specimens positive for Aspergillus sp. (A. fumigatus 95% and A. niger 5%). Among them, 66% had a single positive specimen (14.3% with a positive smear) and 33% had several positive specimens (mean 4.9 +/- 3.3). Four patients (20%) with a more than 20-month history of AIDS and less than 36 CD4+ cells per microliter had documented pulmonary aspergillosis; three of these patients also had a current or past history of pulmonary mycobacterial infection. Rate of recovery of Aspergillus sp. in LAB specimens was low. The other specimens were harvested because of clinically suggestive manifestations. However, in 20% of patients with positive specimens. A. fumigatus was the cause of patent infection; these patients had severe AIDS-related immunodeficiency.

AIDS-Related Opportunistic Infections↗

PubMed2004

Field study on changes in viability of airborne fungal propagules exposed to UV radiation.

The responses of airborne fungi to UV-B under natural conditions were investigated at the coastal station in Preila, Lithuania. Results of this investigation demonstrated that solar radiation has a marked lethal effect on outdoor airborne fungi. Sensitivity to solar radiation was the highest for the fungal propagules collected late in the evening (relative recovery 6.2%) and early morning (25.3%). The lowest sensitivity to solar radiation was observed for fungal propagules collected at midday (50.0%) and in the afternoon (53.0%). The reason for the lethal effect is thought to be elimination of the sensitive fraction of the night-time fungal populations as solar radiation gradually increases beginning at dawn. Among 356 fungus strains isolated during the investigations, 128 can be characterized as potential pathogens, and 21 strains among those most common in fungal populations belonging to plant, animal, and human pathogen groups. The collected fungal populations were exposed to solar UV-B irradiation for 2 h (from 12 p.m. to 2 p.m.). Fungal communities in the air samples were composed of saprotrophs, some of which are regarded as potential phytopathogens (Alternaria, Cladosporium, and Fusarium) or as entomopathogens (Beauveria, Paecilomyces, and Metarhizium). The airborne fungal species identified after exposure to solar radiation were predominantly: Aspergillus niger, Alternaria alternata, Cladosporium cladosporioides, Arthrinium phaerosporum, and dematiaceous sterile mycelium.

Air Microbiology↗

PubMed2002

Pathogenic-bacterial water contamination in mountainous catchments.

This space-time study of bacteriological response compared the presence of pathogens with indicators contained in surface and groundwater in mountainous regions. A systematic search for bacteria such as Listeria, Salmonella, Campylobacter and Yersinia carried out simultaneously with a search for indicators has shown that these waters can occasionally contain potentially pathogens, though these are generally to be found in small quantities. The most common pathogens found are Campyobacter and Listeria. Salmonella has never been isolated. The presence of pathogens is usually accompanied by the presence of classic indicators of contamination such as Escherichia coli, enterococci and other aerobic bacteria. Exceptions are only to be observed in cases of samples presenting very low numbers of pathogens. Such low pathogen levels have a minimal impact on human health; but we cannot exclude that, during periods affected by specific conditions, higher levels might temporarily occur. Our research has demonstrated that classic indicators can be considered as efficient detectors of pathogens in most cases. When these indicators are used systematically and regularly, the human health hazard can be qualified as low but not negligible. The presence of pathogens, together with their survival capacity, brings the protection measures currently applied to safeguard drinking waters sharply into question.

Campylobacter↗

PubMed2006

Etiology of chronic diarrhea in antiretroviral-naive patients with HIV infection admitted to Norodom Sihanouk Hospital, Phnom Penh, Cambodia.

BACKGROUND: Although both human immunodeficiency virus (HIV) infection and diarrhea are considerable problems in Cambodia, there have not been any studies to determine the history, clinical presentation, and etiology of chronic diarrhea in patients with HIV infection in Cambodia. In this article, we present a case-control study involving 40 HIV-infected patients with chronic diarrhea and 40 HIV-infected patients without diarrhea. METHODS: Clinical, demographic, and laboratory data were collected. Stool samples were examined for parasites, including Cryptosporidium species (by partial acid-fast stain), bacterial pathogens, and rotavirus. Samples from 10 case patients and 10 control subjects were also analyzed for Cryptosporidium species by polymerase chain reaction-restriction fragment-length polymorphism. RESULTS: The median CD4(+) cell count was 11.5 cells/mm(3). A potential pathogen was found in 30 case patients (75%) and 29 control subjects (72.5%). Cryptosporidium was the most common pathogen, present in 16 case patients (40%) and 20 control subjects (53.3%). The presence of Cryptosporidium was confirmed by polymerase chain reaction-restriction fragment-length polymorphism, with a prevalence of 40% in each of the 2 groups of 10 subjects who were enrolled for Cryptosporidium evaluation. CONCLUSIONS: Subjects in this cohort had severe immunosuppression. The prevalence of pathogens, including Cryptosporidium, was extremely high but did not differ significantly between the case patients with diarrhea and the control subjects without diarrhea. Further studies are needed to examine factors associated with Cryptosporidium carriage and the natural history of asymptomatic infection.

AIDS-Related Opportunistic Infections↗

PubMed2007

Abnormal kappa:lambda light chain ratio in circulating immune complexes as a marker for B cell activity in juvenile idiopathic arthritis.

Patients with juvenile idiopathic arthritis (JIA) have been shown to have elevated levels of circulating immune complexes (CICs) which correlated with disease activity. Our aim was to assess B cell activity by measuring the amount of and the kappa:lambda chain immunoglobulin light (L) chain ratio in CICs from JIA patients and to determine potential evidence for either an antigen-driven response or B-cell receptor editing. We used an enzyme-linked immunosorbent assay to measure kappa and lambda chains present in the CICs from the sera of patients with JIA. Statistical analysis was performed using Pearson's correlation, one-way ANOVA and Bonferroni post hoc analysis. Sera from 44 JIA patients were examined for the concentration of L chains in CICs. Healthy controls had a kappa:lambda chain ratio of 1.2:1, whereas this ratio was reversed among JIA subgroups with RF-positive polyarthritis (1:1.2), RF-negative polyarthritis (1:1.3), oligoarthritis (1:2.3) and systemic-onset arthritis (1:2.5). In addition, overall lambda chain selection was not significantly associated with a particular immunoglobulin heavy (H) chain and occurred with all immunoglobulin isotypes. We showed preferential selection of lambda chains contributing to the formation of potentially pathogenic CICs from JIA patients, of all onset types compared to healthy controls, in an H chain-independent manner. The reversal of kappa:lambda chain ratio within the JIA CICs and association with all immunoglobulin isotypes demonstrated the potential for L chain editing. Furthermore, we conclude that a reversal of the normal kappa:lambda chain ratio in JIA CICs may be used as a marker for increased B-cell activity.

Adolescent↗

PubMed1997

Clinical role for a superantigen in Yersinia pseudotuberculosis infection.

Yersinia pseudotuberculosis is an enteric pathogen that causes a variety of clinical symptoms in the human. Recently, we reported the production of a superantigen (Y. pseudotuberculosis-derived mitogen, YPM) by this organism and characterized the gene structure of ypm. To further study the potential pathogenic role of YPM in Y. pseudotuberculosis infection, we assayed IgG anti-YPM antibodies and T cell antigen receptor-Vbeta expression of the T cells in peripheral blood and in mesenteric lymph node in patients acutely infected with Y. pseudotuberculosis. 20 out of 33 patients (61%) had an elevated antibody titer compared with healthy controls (P = 0.0001). Patients with systemic symptoms such as lymphadenopathy, transient renal dysfunction, and arthritis had significantly higher titers of anti-YPM than patients with gastrointestinal tract symptoms alone. T cells bearing the Vbeta3 gene segment were significantly increased (P = 0.009) among acute phase patients compared with healthy children. During the convalescence phase of the illness, there was a reduction in the abnormal level of Vbeta3 T cells. Moreover, in the mesenteric lymph node, an elevated level of Vbeta3 T cells compared with peripheral blood and a sequence diversity in the junctional region of the T cell antigen receptor beta-chain containing Vbeta3 element was observed in one patient. Together, these findings suggest that YPM was produced in vivo and played an important role in the pathogenesis of Y. pseudotuberculosis infection.

Adolescent↗

PubMed1998

Upper respiratory tract infections in family practice.

The causative pathogens in the majority of mild to moderate upper respiratory tract infections are Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis. Bacterial infections of the respiratory tract are often treated empirically; however, the recent increase in serious infections caused by S. pneumoniae and rising antimicrobial resistance rates have prompted experts to reevaluate the therapeutic approaches to treatment of these infections. Although amoxicillin continues to be considered a first line therapy, some situations warrant alternative therapies. Antimicrobial therapy must provide effective coverage of the potential pathogens, yet issues of compliance must also be addressed to ensure clinical success. Ease of administration, taste and the potential for adverse events are important considerations for the pediatric population. Clinical trials support the use of alternative therapies in the treatment of patients with upper respiratory tract infections.

Anti-Bacterial Agents↗

PubMed2006

Are therapeutic ultrasound units a potential vector for nosocomial infection?

BACKGROUND AND PURPOSE: Nosocomial infections present a widespread problem in today's healthcare environment, with a significant number of patients acquiring an infection annually. With the contemporary transition of immunocompromised and high-risk patients to community-based care, therapeutic ultrasound has the potential to be a vector of infection in the physiotherapy setting. The purpose of the present study was to determine the degree of contamination on therapeutic ultrasound transducer heads and ultrasound gel after routine clinical use, and to evaluate the efficacy of recommended infection control procedures. METHOD: The study consisted of two phases. Using a prospective cross-sectional design, microbiological cultures were obtained from 44 transducer heads and 43 gels. Subjects were drawn from a variety of physiotherapy practice settings. All samples containing more than five colony forming units per cm2 were considered contaminated. Following these measurements, a repeated-measures design was used to re-evaluate the 44 transducer heads for the amount and type of bacteria present after cleaning with a 70% alcohol wipe. RESULTS: Twenty-seven per cent of transducer heads and 28% of gels were contaminated. Transducer heads showed fairly low levels of contamination across the sample, with the majority of organisms isolated found in normal skin and environmental flora. Gels were heavily contaminated with opportunistic and potentially pathogenic organisms, including Stenotrophomonas maltophilia, Staphylococcus aureus, Acinetobacter baumannii and Rhodotorula mucilaginosa. No multi-resistant organisms were identified. Cleaning with 70% alcohol significantly reduced the level of contamination on transducer heads (p < 0.01). CONCLUSIONS: Therapeutic ultrasound equipment is a potential vector for nosocomial infection in physiotherapy patients. The risk of infection from transducer heads can be effectively removed by cleaning with 70% alcohol between patients. Further research into possible strategies to reduce the risk of infection from ultrasound gels is needed.

Acinetobacter baumannii↗

PubMed1984

Symposium on infectious complications of neoplastic disease (Part II). Chemoprophylaxis of bacterial infections in granulocytopenic patients.

Several prospectively randomized trials have shown that the administration of prophylactic oral nonabsorbable antibiotics may be beneficial in decreasing the incidence of infection in granulocytopenic patients, whereas others have not. Intolerable nausea and vomiting have prevented the prolonged use of these agents in some studies. Discontinuation of therapy while patients are still granulocytopenic has carried the risk of life-threatening infections, often with aminoglycoside-resistant gram-negative organisms. The benefit of selective decontamination with trimethoprim/sulfamethoxazole used prophylactically remains controversial. The use of trimethoprim/sulfamethoxazole may also be associated with the development of resistant, potentially pathogenic, organisms or prolonged neutropenia. These regimens do not appear to be indicated when patients are anticipated to be neutropenic for less than three weeks. Even in patients with prolonged neutropenia, the risks of such treatment must be weighed against potential benefits.

Acute Disease↗

PubMed2005

Genetic and molecular analysis of GogB, a phage-encoded type III-secreted substrate in Salmonella enterica serovar typhimurium with autonomous expression from its associated phage.

Salmonella enterica serovar Typhimurium is lysogenized by several temperate bacteriophages that encode lysogenic conversion genes, which can act as virulence factors during infection and contribute to the genetic diversity and pathogenic potential of the lysogen. We have investigated the temperate bacteriophage called Gifsy-1 in S.enterica serovar Typhimurium and show here that the product of the gogB gene encoded within this phage shares similarity with proteins from other Gram-negative pathogens. The amino-terminal portion of GogB shares similarity with leucine-rich repeat-containing virulence-associated proteins from other Gram-negative pathogens, whereas the carboxyl-terminal portion of GogB shares similarity with uncharacterized proteins in other pathogens. We show that GogB is secreted by both type III secretion systems encoded in Salmonella Pathogenicity Island-1 (SPI-1) and SPI-2 but translocation into host cells is a SPI-2-mediated process. Once translocated, GogB localizes to the cytoplasm of infected host cells. The genetic regulation of gogB in Salmonella is influenced by the transcriptional activator, SsrB, under SPI-2-inducing conditions, but the modular nature of the gogB gene allows for autonomous expression and type III secretion following horizontal gene transfer into a heterologous pathogen. These data define the first autonomously expressed lysogenic conversion gene within Gifsy-1 that acts as a modular and promiscuous type III-secreted substrate of the infection process.

Amino Acid Sequence↗

PubMed2006

Differential sensitivities of pathogens in red cell concentrates to Tri-P(4)-photoinactivation.

BACKGROUND AND OBJECTIVES: Photodynamic treatment (PDT) with the cationic porphyrin, mono-phenyl-tri-(N-methyl-4-pyridyl)-porphyrin chloride [Tri-P(4)], has previously been shown to be effective at inactivating vesicle stomatitis virus (VSV) in red cell concentrates (RCC) with limited damage to red blood cells (RBC). The aim of this study was to determine the pathogen-inactivating capacity of PDT with Tri-P(4) for a broader range of pathogens and to establish the associated effect on in vitro RBC quality. MATERIALS AND METHODS: A series of viruses and bacteria was spiked into 60% RCC. Pathogen inactivation was determined after PDT with 25 microm Tri-P(4) and red light up to 360 kJ/m2. Human immunodeficiency virus (HIV)-infected cells were evaluated for cell death induction, and RCC were analysed for the induction of haemolysis and ATP content. RESULTS: For the lipid-enveloped viruses bovine viral diarrhoea virus, HIV and pseudorabies virus, and for the Gram positive bacterium, Staphylococcus aureus, and the Gram-negative bacteria, Pseudomonas aeruginosa and Yersinia enterolitica, inactivation of > or = 5 log10 was measured after 60 min of PDT with Tri-P(4). The required treatment time to achieve this level of inactivation was four times longer than required for VSV. For cell-associated HIV, only 1.7 log10 of inactivation was found, despite clear induction of cell death of HIV-infected cells. The non-enveloped virus, canine parvovirus, was completely resistant to the treatment. PDT of RCC with Tri-P(4) for 60 min, and subsequent storage in AS-3, resulted in 4% haemolysis after 35 days of storage. The ATP content of untreated and treated RBC declined with similar kinetics during storage. CONCLUSION: PDT of RCC with Tri-P(4) for 60 min inactivates a wide range of pathogens, but not cell-associated HIV and a non-enveloped virus, and compromises RBC quality. This reduces the suitability of PDT with Tri-P(4) for red cell sterilization. Therefore, further improvements in the treatment procedures to potentiate pathogen inactivation and to preserve RBC integrity will be required to generate an effective treatment for sterilizing RCC.

Anti-Bacterial Agents↗

PubMed1996

Concentrations of ceftriaxone (1,000 milligrams intravenously) in abdominal tissues during open prostatectomy.

Ceftriaxone concentrations in abdominal tissues were evaluated at different stages of open prostatectomy. Ceftriaxone was administered as antibiotic prophylaxis, and 15 consecutive patients were given a single dose of ceftriaxone (1,000 mg intravenously in 1 min) 30 min before surgery. Ceftriaxone concentrations in tissue were determined at three stages of the surgical procedure; upon the opening of the abdominal cavity, during the prostatectomy, and upon the closure of the abdominal cavity. Samples of the following tissues or sample were assayed: epiploic and abdominal-wall fat; Retzius' space, bladder, and prostate tissue; and urine. During the different stages of the surgical procedure, for all patients, and in the different tested tissues, ceftriaxone concentrations greater than or equal to the cutoff point (4 micrograms/g of tissue) were measured. The highest concentrations were obtained in the bladder (43 +/- 18 micrograms/g) and in the prostate (35 +/- 18 micrograms/g). In fatty tissues, concentrations were between 13 +/- 5 and 22 +/- 8 micrograms/g. All patients (15 of 15) had ceftriaxone levels in tissue greater than the MICs for the potential pathogens (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis). In conclusion, during open prostatectomy and after the use of a single dose of ceftriaxone (1,000 mg), high antibiotic levels were obtained throughout the surgical procedure in the tissues potentially involved in postoperative infection.

Abdominal Muscles↗

PubMed2000

Keratinopathogenic mould fungi and dermatophytes in healthy and diseased hooves of horses.

Specimens of hoof horn from 187 horses were examined for a possible relationship between clinically affected hooves and the occurrence of pathogenic fungi. Specimens were taken from the coronary band and from the stratum externum and medium of the coronary horn and transferred on to Sabouraud dextrose agar, with and without cycloheximide, and incubated at 28 degrees C. Dermatophytes and mould fungi were identified by their macroscopic and microscopic characteristics. The 732 isolates could be assigned to 26 species of moulds, two different species of the dermatophyte Microsporum and three different species of the dermatophyte Trichophyton. Depending on their pathogenic potential they were assigned to three groups: (i) fungi known to be keratinopathogenic (Acremonium blochii, Alternaria alternata, Alternaria chlamydospora, Geotrichum candidum, Microsporum ferrugineum, Microsporum gypseum, Scopulariopsis brevicaulis, Trichophyton species, Trichophyton mentagrophytes, Trichophyton schönleinii, 57 isolates), (ii) a group of uncertain pathogenicity (223 isolates), and (iii) a group of non-pathogenic species (452 isolates). Eighty per cent of the samples from horses with hoof horn lesions and 66.7 per cent of the samples from horses with slightly affected hoof horn contained fungi of the keratinopathogenic group, whereas only 8.9 per cent of the samples from horses with healthy hoof horn contained fungi of this group. There were no significant correlations between the clinical data and the age, sex or breed of the horses or their bedding and hygiene. Twelve species of fungi were isolated from the air in the horses' stables, but none of them belonged to the keratinopathogenic group.

Animals↗

PubMed1980

Mastitis and udder abnormalities as related to neonatal lamb mortality in shed-lambed range ewes.

Bacterial isolations were attempted from milk samples taken from 242 range ewes in a southwestern Idaho shed lambing enterprise. Eighty-five percent of the ewe milk samples had no pathogenic bacterial growth at lambing and 3 weeks later. The few organisms that were isolated did not appear to affect udder condition of the ewe or contribute to lamb mortality. Shed conditions did not affect the frequency of isolation of potentially pathogenic bacteria. The prevalence of udder abnormalities, however, did appear to have a positive association with ewes that lost theim lambs. The most frequent abnormality was a diffuse homogeneous induration of the udder. This hardening was apparently unrelated to bacterial isolation or the age of the ewes. Mastitis, either subclinical or clinical, did not appear to be a serious problem in this particular flock. Mastitis was not related to lamb mortality.

Animals↗

PubMed2004

The new mycobacterial species--emerging or newly distinguished pathogens.

Diseases due to nontuberculous mycobacteria are increasing in frequency, especially in patients with compromised immunity. A number of "new" mycobacterial species have been described in the last decade, largely as the result of the use of new tools to identify previously unrecognized mycobacteria found in the environment and in clinical specimens. This article reviews many of these potentially pathogenic organisms, summarizing what is known regarding their phenotypic and genotypic characterization, antimicrobial susceptibility, and clinical significance.

Communicable Diseases, Emerging↗

PubMed2006

[Significance of Escherichia coli O157 in sheep at slaughter in Switzerland].

The importance of latent zoonoses has increased in recent years in view of foodborne diseases: (i) the "healthy" animal repesents a reservoir for specific pathogens; () no pathological-anatomical changes in the carcass and its organs show the presence of these pathogens; and (iii) these pathogens may enter the food chain via hygienic weak points in the slaughtering process. To estimate the risks involved and to take appropriate measures, analysis of the slaughtering process should be complemented by collecting data relating to the carriage of the animals of latent zoonotic pathogens. From October 2004 to June 2005, fecal samples from 630 slaughtered sheep were enriched and then examied by IMS technique and by PCR to assess the prevalence of E. coli O157 (OE). Seven samples (1.1%), distributed throughout the whole examination period, were found to be positive. To assess the potential pathogenicity for humans, E. coli O157 strains were isolated by colony hybridization and further characterized. The isolated strains fermented Sorbitol, showed four different H tys (H7, H12, H38, H48), and were all negative for stx. One O157:H7 strain harbored the gene for intimin (eae) in combination with ehxA, and paa. In consequence, the potential health hazard from sheep meat related to O157 STEC seems current not to be of particular importance in Switzerland. Results emphasize the fact that E. coli O157 are not always STEC but may belong to other pathotypes as nontraditional EPEC.

Abattoirs↗