Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Potential pathogens”

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 1,297 records · Page 72Linked to original sources
PubMed2005

Significance of bacteria associated with invertebrates in drinking water distribution networks.

The implication of invertebrates found in drinking water distribution networks to public health is of concern to water utilities. Previous studies have shown that the bacteria associated with the invertebrates could be potentially pathogenic to humans. This study investigated the level and identity of bacteria commonly associated with invertebrates collected from the drinking water treatment systems as well as from the main pipelines leaving the treatment works. On all sampling occasions bacteria were isolated from the invertebrate samples collected. The highest bacterial counts were observed for the samples taken before filtration as was expected. There were, however, indications that optimal removal of invertebrates from water did not always occur. During the investigation, 116 colonies were sampled for further identification. The isolates represent several bacterial genera and species that are pathogenic or opportunistic pathogens of humans. Diarrhoea, meningitis, septicaemia and skin infections are among the diseases associated with these organisms. The estimated number of bacteria that could be associated with a single invertebrate (as based on average invertebrate numbers) could range from 10 to 4000 bacteria per organism. It can, therefore, be concluded that bacteria associated with invertebrates might under the worst case scenario pose a potential health risk to water users. In the light of the above findings it is clear that invertebrates in drinking water should be controlled at levels as low as technically and economically feasible.

Animals↗
PubMed1993

The demyelinating potential of antibodies to myelin oligodendrocyte glycoprotein is related to their ability to fix complement.

A panel of 13 monoclonal antibodies (mAbs) has been raised to the central nervous system-specific glycoprotein, myelin oligodendrocyte glycoprotein; five of these mAbs recognize a carbohydrate epitope on the molecule. Although all of the mAbs recognized surface epitopes on cultured oligodendrocytes and stained central nervous system tissue sections in a similar manner, marked differences were seen in their ability to induce demyelination in experimental allergic encephalomyelitis in the Lewis rat. This variation in pathogenic potential was not related to the specificity of a given mAb for carbohydrate or peptide epitopes of myelin oligodendrocyte glycoprotein, but correlated with its ability to fix complement.

Animals↗
PubMedDate not supplied

Does earwax lose its pathogens on your auriscope overnight?

OBJECTIVES: To describe the organisms cultured from general practitioners' auriscope earpieces; and to explore general practitioners' perceptions of the possibility of cross infection from contaminated auriscope earpieces and of how their auriscope earpieces are cleaned. DESIGN: Microbiological survey of auriscope earpieces in two general practices and a semistructured questionnaire sent to 105 general practitioners. SETTING: General practitioners served by one district general hospital microbiology laboratory in the north of England. RESULTS: Organisms were cultured from 41 (93%) of 44 auriscope earpieces, of which 14 (32%) carried potential pathogens; four (9%) were heavily contaminated. Of the 85 (81%) general practitioners who responded, 72 (85%) believed that contaminated auriscope earpieces could cause serious infection, 66 (78%) did not clean earpieces between patients, and 70 (82%) thought that patients would mind if they knew that dirty earpieces were used. CONCLUSIONS: Almost a third of auriscope earpieces were contaminated by pathogenic bacteria. Although general practitioners suspected this, most did not ensure that a clean earpiece was used for each patient.

Attitude of Health Personnel↗
PubMed1983

Community-acquired bacterial pneumonia requiring admission to hospital.

Patients who develop bacterial pneumonia in the community often require admission to acute-care hospitals. Knowledge of the incidence of pneumonia due to different pathogens that are brought into an institution from the community may play a role in determining the patterns of infecting organisms responsible for hospital-acquired pneumonia. For 1 year, we prospectively reviewed the records of patients admitted to our 1000-bed community hospital with community-acquired bacterial pneumonia (CABP). Patients had clinical signs and symptoms, positive radiologic findings, and pure cultures of potential pathogens from sputum, blood, pleural fluid, lung aspirate, lung biopsy, or transtracheal aspirate. Pneumonia due to Legionella pneumophila was diagnosed by serum indirect fluorescent antibody (IFA) titer greater than or equal to 1:256 and clinical signs and symptoms along with response to erythromycin. Of 204 patients with bacterial pneumonia, the following pathogens were implicated: Streptococcus pneumoniae, Haemophilus species, L. pneumophila, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, oral anaerobic bacteria, Psuedomonas aeruginosa, Serratia marcescens, and others. Most patients were more than 50 years of age and many had evidence of underlying pulmonary disease. The etiology of CABP may not be as predictable as in the past. Empiric antimicrobial therapy for CABP should include agents with activity against the pathogens prevalent in the community.

Adult↗
PubMed1981

Experimental cerebral zygomycosis in alloxan-diabetic rabbits: variation in virulence among zygomycetes.

We investigated the potential of 33 different zygomycete isolates to cause cerebral disease following the intranasal instillation of their spores into ketotic rabbits with alloxan induced diabetes. The isolates represented six thermotolerant species of Rhizopus (R. arrhizus, R. chinensis, R. microsporus, R. oligosporus, R. oryzae, and R. rhizopodiformis), Absidia corymbifera, Cunninghamella bertholletiae, and Rhizomucor pusillus. All 13 isolates of the thermotolerant Rhizopus species proved to be cerebral pathogens as confirmed by culture and histopathology. One isolate of R. oligosporus and one isolate of R. rhizopodiformis, however, were less pathogenic than isolates of other Rhizopus species tested. Cerebral pathogenicity was noted with 2 of 5 isolates of Rh. pusillus and only 1 of 13 A. corymbifera isolates. Two thermotolerant C. bertholletiae cultures, recovered from human lesions, did not cause either cerebral or pulmonary disease in ketotic rabbits. The incidence of pulmonary zygomycosis caused by the isolates of the species of the four genera under study was as follows: Rhizomucor 24%, Rhizopus 22%, Absidia 9%, and Cunninghamella 0%. This study confirms the pathogenic potential of the thermotolerant species of Rhizopus to cause cerebral zygomycosis in ketotic diabetic rabbits and also revealed the potential of Rh. pusillus and A. corymbifera occasionally to cause the same disease in animals and humans.

Alloxan↗
PubMed1999

The role of nonhuman primates in the development of an AIDS vaccine.

Over the past decade, a substantial research investment has generated a vast body of knowledge relevant to the development of an effective AIDS vaccine. Furthermore, studies in nonhuman primates have demonstrated that a number of candidate immunogens can confer a significant degree of protection against a potentially pathogenic SIV or SHIV. Currently, there exists a robust program that supports discovery of new HIV immunogens and a proven successful program for collaborative human trials of promising vaccine candidates. However, we believe that there is a gap between discovery and clinical trials. An orderly process for screening of candidate immunogens prior to human trials would facilitate the vaccine development program. We suggest that nonhuman primates can fill this strategic gap and could accelerate vaccine development. Recognizing that there is considerable controversy about the potential usefulness of the primate models, we have attempted to set forth the relevant practical and biological issues as a series of questions for discussion. The most important biological problem is the absence of a single immune response correlate that will predict vaccine efficacy. Data from primate models indicate that such a single predictive correlate may not exist. In turn, this argues for a vaccine screening protocol that includes a pathogenic virus challenge, an approach only available in the nonhuman primate model. The further assumption is that nonprimate models can be used to predict the relative protective efficacy of diverse immunization protocols, a hypothesis that can only be tested by comparative studies yet to be conducted. A 'standard' set of virus challenges must be selected for comparison of different immunization protocols, and this effort has been initiated. At the practical level, it appears that the large number of candidate immunogens now being developed requires a screening process of the kind proposed, since it would not be practical to test all new immunogens and protocols in humans. In conclusion, it appears timely to crystallize an orderly process for the discovery, screening, and human testing of candidate AIDS vaccines, understanding that a vaccine development program should not be conducted at the expense of investigator-initiated research in the diverse disciplines that support rational vaccine design and development. The components of a rational process of vaccine development are well established and only remain to be welded into one coherent program.

AIDS Vaccines↗
PubMed1985

Association of anurans with pathogenic fungi.

In a study of 450 Amazonian anurans, we isolated yeasts and yeast-like fungi from 54 animals (Bufo granulosus, B. marinus, Dendrophrynyscus sp., Hyla geographica, H. lanciformes, Ololygon rubra, Adenomera hylaedactyla, Eleutherodactylus fenestratus, Leptodactylus fuscus, L. ocellatus, L. pentadactylus). The internal organs of these animals did not show any macroscopic anomaly nor histopathology. We recovered 105 fungal isolates from the anuran liver, lung, kidney, spleen, heart and gonad. The isolates were made up of 30 fungal species, 9 of which (48 isolates, 46%) were fungi with known pathogenic potentials, namely: Candida guilliermondii, C. parapsilosis, C. tropicalis, C. glabrata, Geotrichum candidum, Aureobasidium pullulans, Wangiella dermatitidis, Trichosporon cutaneum and Exophiala werneckii. Eleven animals harbored identical fungi in more than one of their internal organs; seven animals had more than one fungal species colonizing a single organ. Our findings indicated probable natural subclinical infections of candidiasis, geotrichosis or phaeohyphomycosis, and also symbiotic presence of non-pathogenic fungi among neotropical anurans.

Animals↗
PubMed1986

Age factors potentiating drug toxicity in the reproductive axis.

Traditionally, drug toxicity in the reproductive system has been a concern only as it affects fertility and fecundity in young individuals. The purpose of this report is to address the potential problem of synergy between drug actions and abnormal secretion of reproductive hormones that together produce disease in older individuals. Thus, reproductive toxicity has different, but no less serious implications in aging individuals. During aging, the coordinated function of elements within the reproductive neuroendocrine axis degrades. This change promotes atypical secretion of hormones producing abnormal responses in target organs and thus creates a condition with pathogenic potential. Certain drugs may contribute to reproductive toxicity in aging individuals either by accelerating the process of dysregulation and/or by synergizing with hormones to stimulate pathologic changes in target tissues. The geriatric population of the world is increasing, and since it consumes a proportionately larger percentage of drugs than younger groups, this novel form of reproductive toxicity may represent a problem in drug safety that warrants serious consideration.

Aging↗
PubMed2006

Common house spiders are not likely vectors of community-acquired methicillin-resistant Staphylococcus aureus infections.

There is an increasing incidence in the number of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections in the United States. Skin and soft tissue infections caused by MRSA are often perceived as being preceded by a spider bite. Several possibilities exist to explain this phenomenon, including 1) spiders introduce MRSA into the bite wound and thereby serve as a potential vehicle or vector for MRSA; 2) MRSA colonization is an event secondary to the spider bite; and 3) the spider bite is a misguided way for patients or their physicians to explain the initial lesion of their skin or soft tissue infection. We hypothesized that if spiders were able to serve as vehicles or vectors for MRSA infections, they would be colonized with this pathogen. To test this hypothesis, we captured common household spiders and determined the patterns of normal microbial flora isolated from them. Spiders were collected from several homes by their occupants, photographed for identification, and cultured for external and internal microbial flora. Of > 100 spiders collected, none was found to carry Staphylococcus aureus or MRSA. Relatively low numbers of microbial flora were isolated, and only a single isolate with pathogenic potential in humans (Aeromonas spp.) was isolated. Common house spiders are unlikely to be a source of MRSA.

Animals↗
PubMed1994

[Hospital infection in pediatric patients].

Hospital (nosocomial) infection means infection acquired by patients while they are in hospital, or by members of hospital staff. It will occur in modes of three categories; 1) cross-infection (infection acquired in hospital from other people, either patients or staff), 2) self-infection (infection caused by microbes which the patient carries on normal or infected areas of his own body) and 3) self-infection after acquisition of hospital pathogens from other people or the environment. Examples of hospital infections, that we experienced, were presented as follows; cross-infection due to gram-negative organisms as Pseudomonas aeruginosa and Acinetobacter in neonatal intensive care unit, cross-infection due to viruses as RS in infants with cardiovascular diseases and varicella in immunocompromised patients, and self-infection supervening cross-infection due to potential pathogens including MRSA in immunocompromised children as patients with malignant blood diseases and surgeries. The most important preventive measure for cross-infection would be isolation of the infected or colonized patients and hand-washing. To prevent self-infection, it is essential to maintain the defensive ability of patient including normal flora, and active immunization or prophylactic antibiotic treatment will be needed in some patients. Administration of antibiotics often permits selection and overgrowth of multiply resistant microorganisms and results in serious infections. Therefore, antibiotic policy would be mandatory in each hospital.

Acinetobacter Infections↗
PubMed2003

Application of the molecular analysis of the T-cell receptor repertoire in the study of immune-mediated hematologic diseases.

The basis for the vast recognition spectrum of the T-cell receptor (TCR) can be determined by the rearrangement and recombination of the variable, diversity and joining regions of the variable portions of beta (B) and alpha (A) chains as well as their recombination and modification. Analysis of the TCR rearrangement has been routinely used to detect clonality for the diagnosis of lymphoid malignancies. However, molecular analysis of the TCR repertoire can be a powerful tool in the study of T-cell responses to pathogens and in autoimmune diseases. The concept of the oligoclonality in the context of cellular immune responses is based on the presence of immunodominant T-cell clones within distinct T-cell subpopulations used for analysis. Under normal circumstances, a limited number of clones undergo periodic expansions in reaction to foreign antigens. Under pathologic conditions, though, the derailment of immune regulation allows expansions of specific and potentially pathogenic T-cell clones. For example, large granular lymphocyte (LGL) leukemia illustrates an extreme expansion of a single T-cell clone associated with a distinct autoimmune pathology, which suggests an exaggerated clonal response to a specific antigenic target. In immune-mediated bone marrow failure syndromes, clonal rearrangement of the TCR cannot be detected in unseparated blood or marrow. Nevertheless, individual T-cell clones can significantly expand and may allow for demonstration of oligoclonality in selected T-cell populations. These subpopulations are defined, for example, by a specific beta (B)-chain usage or other phenotypic markers. Given the diversity of the TCR recognition spectrum, the task of identifying immunodominant clonotypes derived from unique complementarity determining region-3 (CDR3) sequences is very complex. However, expanded T-cell clones likely represent immunodominant responses which can be detected on the molecular level using analysis of the individual TCR VB-chain representation, CDR3 size fragment skewing, and determination of the frequency of individual clonotypic sequences. In the future, TCR VB clonotypes may be applied as a diagnostic tool, analogous to serologic markers. As an investigative tool in hematology, molecular analysis of the TCR utilization pattern and the detection of immunodominant clonotypes represents a novel approach in the study of immune-mediated hematologic diseases, such as aplastic anemia (AA), some forms of myelodysplasia (MDS), anti-leukemic immune surveillance, graft-versus-leukemia effects and graft-versus-host disease (GvHD).

Anemia, Aplastic↗
PubMed2005

Etiology of ulcerative lesions of Atlantic menhaden (Brevoortia tyrannus) from James River, Virginia.

We observed ulcerative lesions on live Atlantic menhaden, Brevoortia tyrannus, during ichthyofaunal sampling in the tidal James River in October 1999 (near Jamestown, VA, USA). Other synoptically collected fishes exhibited no signs of lesions or pre-ulcerative tissues. Live fish were classified as unremarkable (no dermal anomalies), pre-ulcerative (integument intact with boil-like swelling), and ulcerative (severe focal lesions). Specimens were analyzed for bacteria, fungi, and pathogenic protozoans including amphizoic amoebae, Pfiesteria piscicida, and Kudoa sp. No Pfiesteria were detected in any tissue specimen. All B. tyrannus examined, including tissues from unremarkable fish, tested positive for presence of the known fish parasite Kudoa. Only ulcerative lesions were also colonized by bacteria, fungi, and amphizoic amoebae. The absence of bacteria, fungi, and protozoans from unremarkable and pre-ulcerative fish suggests that association of other potential pathogens with B. tyrannus ulcers was due to secondary colonization following lesion formation as a result of Kudoa infection.

Animals↗
PubMed1986

A 2-year survey of Branhamella catarrhalis in a general hospital.

During a 2-year period, 143 strains of Branhamella catarrhalis were recovered from 7929 respiratory tract specimens (mainly sputa) sent for routine microbiological investigations at a 500 bed general hospital. The incidence of beta-lactamase positive strains increased from 2.7% in 1983 to 40% of isolates in the last 5 months of 1984; this increase continued in the early months of 1985. Forty-four strains of Bran. catarrhalis recovered from 35 patients were considered on laboratory generated data potentially pathologically significant. Almost half of the beta-lactamase producing strains were recovered from these 35 patients. Clinical information from 21 of these patients revealed the isolates in all cases to be associated with the advent of a respiratory tract infection. Appropriate antibiotic therapy in 16 of the 21 patients resulted in clinical improvement although in only 11 of these was Bran. catarrhalis specifically considered the causative pathogen. Underlying lung pathology seemed a major factor in permitting Bran. catarrhalis to express its pathogenic potential.

Bacterial Infections↗
PubMedDate not supplied

Clinical manifestations of Kingella kingae infections: case report and review.

A patient with antecedent coccidioidal pulmonary cavitary disease who developed an empyema due to Kingella kingae prompted our analysis of the literature regarding this unusual bacterial pathogen. Formerly classified among other genera and considered a nonpathogen, K. kingae has been increasingly recognized as a cause of human infection. While the most commonly diagnosed infections due to this organism are endocarditis and septic arthritis, there have also been isolated reports of bacteremia, diskitis, abscesses, meningitis, and oropharyngeal infections. The treatment of choice is penicillin, to which K. kingae strains are uniformly susceptible. Recognition of the potential pathogenicity of this microorganism in appropriate clinical settings will probably result in more prompt and specific therapy.

Bacterial Infections↗
PubMed1979

Meningococcal group Y pneumonia in an adolescent female.

Neisseria meningitidis group Y has been considered to be an uncommon pathogen. Meningococcal group Y disease has recently been reported with increased frequency in military training camps coincident with the routine use of meningococcal group C vaccine. Pneumonia produced by the group Y organism may mimic disease caused by common respiratory tract pathogens, and isolation by routine methods may be difficult. A 16-year-old asthmatic female developed lobar pneumonia secondary to N meningitidis group Y while on alternate day steroids. We speculate that neither steroid therapy nor an isolated serum IgA deficiency in the presence of secretory IgA discovered after her recovery predisposed her to sinopulmonary disease. The true incidence of group Y disease is unknown. Awareness of its potential pathogenicity may have clinical significance with the availability of a group Y vaccine.

Adolescent↗
PubMed1996

[HIV infection: recommendations for the management of asymptomatic adults and of various clinical syndromes].

This paper presents recommendations on the care of HIV infected adults based upon the authors' personal experience with close to 700 patients in a multiprofessional pilot center. This medical care has 5 main objectives: 1) Promotion of good health (through standard recommendation of hygiene, health habits and regular checkups); 2) prevention of infectious complications (through detection of latent pathogens, chemoprophylaxis, vaccination and avoidance of risky exposures); 3) Treatment of complications (mainly infectious, through early diagnosis and proper treatment); 4) Delay of HIV disease progression (through timely and properly chosen antiretroviral therapy); 5) Reduction of HIV infection spread from index case to others (through promotion of responsible behavior and avoidance of pregnancy and HIV exposure to others). Studies for evaluating global health and immunologic status and carriage of potential pathogens are discussed as well as the criteria and timing for chemoprophylaxis for tuberculosis and P carinii pneumonia (PCP). Algorithms for the management of major clinical syndromes are presented: Diarrhea (afebrile, mostly parasitic, versus febrile, frequently bacterial); Pneumonia (lobar mostly bacterial versus interstitial, frequently PCP especially if lymphopenic and not receiving PCP prophylaxis); Brain mass lesion (most commonly toxoplasmosis). Finally, the evaluation and diagnostic possibilities of febrile patients is presented, based upon the immunologic status and associated symptoms.

AIDS-Related Opportunistic Infections↗
PubMed2002

[Parvovirus B19 myocarditis in a young man with previous non-bacterial meningitis].

HISTORY AND CLINICAL FINDINGS: A 22-year old man presented with fatigue, dyspnea NYHA III and presyncopes that had persisted since a non-bacterial meningitis 3 months before. INVESTIGATIONS: Transthoracic echocardiography revealed a dilated left ventricle with an ejection fraction (EF) reduced to 35-40 % due to global hypokinesia. No pericardial effusion was seen; ECG and lung function test were normal. Serological, immunological and microbiological tests as well as nested PCR analysis of blood leucocytes for detection of cardiotropic pathogens were inconclusive. In endomyocardial biopsies retrieved from the left ventricular posterolateral wall, a chronic macro-phage-rich myocarditis was shown by histopathology and, in addition, Parvovirus B19 was identified as specific pathogen by use of nested PCR analysis. TREATMENT AND COURSE: At physical rest and with ACE inhibitor therapy (2.5 mg ramipril/day), heart failure decreased steadily. Follow-up echocardiography 1 month later revealed a left ventricle that was only slightly dilated with an EF of 50 %. 3 months later, the patient was markedly more load-bearing; the EF amounted to 55-60 %. CONCLUSIONS: Parvovirus B19 should be regarded as potential pathogen in case of suspected myocarditis in adulthood. Whether the previous non-bacterial meningitis was also attributable to this specific pathogen, remains open. Of note, however, the present case report by demonstrating a localized myocardial Parvovirus B19 infection without detectable systemic infection underscores the importance of molecular tests for diagnostic accuracy in manifest organ failure.

Adult↗
PubMed1975

Untraditional glucose fermenting actinomycetes as human pathogens. Part II: Rothia dentocariosa as a cause of abdominal actinomycosis and a pathogen for mice.

Rothia dentocariosa was proved as a primary pathogen for man in the case of abdominal infection of a 19 year old woman. Clinical findings were typical for actinomycosis and the patient was cured with penicillin following surgery. Actinomycotic granules were proved by direct microscopy in the pus and R. dentocariosa was recovered as a single pathogen according to the microscopy. Two morphologically distinct isolates recovered from primocultures were described. They were studied separately and finally they were recognized as physiologically identical varieties of a single organism. In addition, the two morphological varieties of R. dentocariosa were considered to represent a particular kind of variability of the A-N type. The isolated germ was found to be pathogen for mice. Intraperitoneal infections provoked multiple nodules formation which were grown into the internal organs of experimental animals. The nodules were encapsulated and tended to spread without regard to the natural tissue plan. They contained pus involving microgranules of viable germs. This first report of the natural human infection caused by R. dentocariosa is the precedent for the definite establishing of this aerobic glucose fermenting actinomycete amidst the untraditional potential pathogens of human actinomycosis.

Actinomycetaceae↗