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At least 1,351 records · Page 75Linked to original sources
PubMed2005

Methicillin-resistant Staphylococcus aureus as a pathogen in deep neck abscesses: a pediatric case series.

OBJECTIVES: Pediatric deep neck space abscesses are frequently treated by the otolaryngologist. We report four children with deep neck abscesses caused by methicillin-resistant Staphylococcus aureus (MRSA), including the first described case of descending mediastinitis caused by MRSA in a child. METHODS: Records from March 2001 to April 2002 were reviewed. RESULTS: Four patients presented with neck swelling, and three of these also had leukocytosis. All abscess cultures were positive for MRSA. Abscess drainage with antibiotic therapy successfully treated three cases without complication. The fourth case developed descending mediastinitis but survived after additional surgical treatment and prolonged antibiotic therapy. CONCLUSIONS: MRSA should be considered as a potential pathogen in deep neck space abscesses. A high index of suspicion is needed as well as aggressive treatment including incision and drainage along with culture-directed medical therapy. Surgical drainage may be the most important aspect of therapy.

Abscess↗
PubMed1981

Can mother-infant interaction produce vulnerability to schizophrenia?

Schizophrenia is regarded as a final common behavioral syndrome which may be arrived at though a variety of routes. Even with a probably genotype, environmental influence seems necessary for the phenotype to appear. The problem concerns the likelihood of an early experience-induced sequence of events within the person of infant and later adult vs. a continuing pathogenic environment. Either may or may not interact with a continuing genic factor(s) as a source of vulnerability. Vulnerability is here, then, viewed as epigenetically evolving via individual-environment transactions throughout life (although with major impacts from conception through adolescence). At any point, therapeutic intervention may preclude or minimize the actualization of the pathogenic potential. It may begin during pregnancy, with attention to such factors as diet, drugs, physical stress, and illness, influencing fetal development and obstetrical manipulations and the birth process. All influence earliest mother-infant interaction from the point of view both of the infant's evocation of maternal behavior and maternal responsivity. Therapeutic interventions also include attention to the multigenerational context of earliest interaction, with special reference to a woman's relationships with her own mother. At every point, nonspecific protective or pathogenic factors such as social support or stressful precipitating events may become important. Socioeconomic status appears to have a powerful nonspecific influence as the core of a cluster of factors which exert an enduring influence from infancy to adulthood. A continuing specific factor may reside in distorted communicative reciprocity between parent an child rooted in the preverbal period of infant development. Context-mediated cerebral deficits may influence learning capacity, hedonic capacity, behavioral rigidity, and many other factors leading ultimately to impaired social competence and increased vulnerability.

Adaptation, Psychological↗
PubMed1999

[Use of trovafloxacin therapy in community-acquired pneumonia].

In community-acquired pneumonia (CAP) the pathogenic microorganism is unknown at the time of diagnosis. For that reason the antimicrobial therapy is empirical, based in the clinical picture and the presumptive causal microorganisms. Hospitalization is one of the most important decisions in patients with CAP. Clinical criteria appropriate to identifying those patients requiring hospital admission for antimicrobial administration and clinical control must be defined. The stratification of patients according to the presence of risk factors such as age and co-morbidities permit to predict which are the potential pathogenic microorganisms and their adequate therapy. Trovafloxacin covers all the presumed bacterial spectrum, pharmacokinetics, easiness to be administered and to pass to the oral route, advantageous for all the groups under consideration. Patients older than 65 years of age or with co-morbidities and those that need to be hospitalized receive clear benefits from this antibiotic.

Adult↗
PubMed2002

Interstitial deletions at the long arm of chromosome 13 may be as common as monosomies in multiple myeloma. A genotypic study.

BACKGROUND AND OBJECTIVES: Deletions at the long arm of chromosome 13, mostly at the q14, and monosomy of chromosome 13 are described to be common in multiple myeloma (MM). 13q- has been associated with an adverse outcome and it has been proposed as one of the most important prognostic factors for MM patients. Deletions of 13q14 are rare in monoclonal gammopathy of undetermined significance (MGUS) and are thus believed to be associated with the development of the full myeloma phenotype. DESIGN AND METHODS: A genotyping analysis on purified neoplastic plasma cells was performed on 14 consecutive MM cases to determine the minimally deleted region at chromosome 13. Freshly obtained bone marrow was analyzed by flow cytometry in order to establish the percentage of plasma cell infiltration (CD38+BB4+CD56+/-CD19-). Neoplastic enrichment was carried out using BB4 coated immunomagnetic beads. This method allowed us to monitor the enrichment process. DNA obtained from the enriched neoplastic population and DNA from the clean fraction was amplified using combination sets of chromosomes 12 and 13. Amplimers were run on acrylamide gels, analyzed by automatic fluorescence quantification, and their size determined using the software programs Genescan and Genotyper. RESULTS: In 11 patients electropherograms were suggestive of loss of heterozygosity (LOH) for polymorphic markers located at the long arm of chromosome 13. Four patients showed monosomy and 7 had interstitial deletions in the telomeric region. LOH was not evidenced at chromosome 12 in any sample. The minimal region with deletion was defined by the markers D13S159 (13q32.2, centromeric) and D13S1267 (13q32.3, telomeric). A gene with a potentially pathogenic role may be located in this very small region. Three patients did not show LOH at chromosome 13 by genotypic analysis; however, in one of these, proximal deletion at the long arm of chromosome 13 (13q2.1-2.2) was demonstrated by comparative genomic hybridization (CGH). INTERPRETATION AND CONCLUSIONS: These findings suggest that interstitial deletions of the long arm of chromosome 13 may be more common than previously recognized. The methodologic approach reported in this work may simplify LOH analysis in MM patients. The potential uses of genotyping analysis in risk stratification remain to be investigated.

Adult↗
PubMed1976

The biochemical prerequisites for preventing pathogenic lysolecithin activity in the human gallbladder.

Human gallbladder epithelium was disintegrated to complete loss of microscopic structure and incubated at 37 degree C together with unlabelled lysolecithin and 14C-lysolecithin. During each incubation lysolecithin was degraded and stoichiometrically equivalent amounts of free fatty acids formed. The maximum rate of degradation was obtained at pH 7.0 and at 200 muM lysolecithin. With increasing amounts of gallbladder epithelial cell constituents the reaction became faster. After heating the epithelial components at 70 degrees C for 10 min the reaction was inhibited. The results suggest the presence of a heat labile lysophospholipase (phospholipase B) activity in the human gallbladder epithelium. This activity may operate to protect the gallbladder epithelium against potentially pathogenic lysolecithin activity. Its presence in the gallbladder epithelium meets the prerequisites for a local anti-inflammatory mechanism and lends further support to the hypothesis of lysolecithin as a mediator of cholecystitis.

Cholecystitis↗
PubMed1990

Endogenous endophthalmitis due to Salmonella arizonae and Hafnia alvei.

Enteric pathogens rarely involve organs other than those of the gastrointestinal system. We have reported the case of a woman with rheumatoid arthritis who had endogenous endophthalmitis due to Salmonella arizonae and Hafnia alvei. The infection probably resulted from the use of snake powder as a food seasoner. After appropriate intravenous, intraocular, subconjunctival, topical, and oral antibiotic therapy based on laboratory susceptibility studies, the patient's condition clinically improved, but complications resulted in therapeutic enucleation. Because of the ubiquitous nature of these and other potentially pathogenic organisms, great care must be taken in evaluation, management, and education of immunocompromised patients.

Anti-Bacterial Agents↗
PubMed2001

Bacterial diversity in human subgingival plaque.

The purpose of this study was to determine the bacterial diversity in the human subgingival plaque by using culture-independent molecular methods as part of an ongoing effort to obtain full 16S rRNA sequences for all cultivable and not-yet-cultivated species of human oral bacteria. Subgingival plaque was analyzed from healthy subjects and subjects with refractory periodontitis, adult periodontitis, human immunodeficiency virus periodontitis, and acute necrotizing ulcerative gingivitis. 16S ribosomal DNA (rDNA) bacterial genes from DNA isolated from subgingival plaque samples were PCR amplified with all-bacterial or selective primers and cloned into Escherichia coli. The sequences of cloned 16S rDNA inserts were used to determine species identity or closest relatives by comparison with sequences of known species. A total of 2,522 clones were analyzed. Nearly complete sequences of approximately 1,500 bases were obtained for putative new species. About 60% of the clones fell into 132 known species, 70 of which were identified from multiple subjects. About 40% of the clones were novel phylotypes. Of the 215 novel phylotypes, 75 were identified from multiple subjects. Known putative periodontal pathogens such as Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola were identified from multiple subjects, but typically as a minor component of the plaque as seen in cultivable studies. Several phylotypes fell into two recently described phyla previously associated with extreme natural environments, for which there are no cultivable species. A number of species or phylotypes were found only in subjects with disease, and a few were found only in healthy subjects. The organisms identified only from diseased sites deserve further study as potential pathogens. Based on the sequence data in this study, the predominant subgingival microbial community consisted of 347 species or phylotypes that fall into 9 bacterial phyla. Based on the 347 species seen in our sample of 2,522 clones, we estimate that there are 68 additional unseen species, for a total estimate of 415 species in the subgingival plaque. When organisms found on other oral surfaces such as the cheek, tongue, and teeth are added to this number, the best estimate of the total species diversity in the oral cavity is approximately 500 species, as previously proposed.

Bacteria↗
PubMed2005

Identification of HPV variants.

The vast majority of anogenital carcinomas are caused by high-risk human papillomaviruses (HPVs), and among Western nations HPV-16 is usually the most predominant cancer-associated type. As a DNA virus, HPV type 16 has a relatively stable genome that is believed to have co-evolved with its host over the millennia. Nevertheless, among the "wild" populations of HPV-16 that are circulating, a large number of variants have been identified, and these may have considerably different pathogenic potentials. In this chapter, methods for screening and characterizing HPV-16 sequence variants are described. In particular, we describe methods for the identification of variation within the HPV-16 E5 open reading frame and for the detection of the nt 131 A-->G mutation of the E6 ORF, using restriction fragment length polymorphism assays. In addition, we describe approaches for DNA sequencing and analysis. Such methods are likely to be of particular interest to those involved in epidemiological investigations of virus transmission and pathogenicity studies.

Base Sequence↗
PubMed2004

Enhancer-mediated control of macrophage-specific arginase I expression.

Arginase I expression in the liver must remain constant throughout life to eliminate excess nitrogen via the urea cycle. In contrast, arginase I expression in macrophages is silent until signals from Th2 cytokines such as IL-4 and IL-13 are received and the mRNA is then induced four to five orders of magnitude. Arginase I is hypothesized to play a regulatory and potentially pathogenic role in diseases such as asthma, parasitic, bacterial, and worm infections by modulating NO levels and promoting fibrosis. We show that Th2-inducible arginase I expression in mouse macrophages is controlled by an enhancer that lies -3 kb from the basal promoter. PU.1, IL-4-induced STAT6, and C/EBPbeta assemble at the enhancer and await the effect of another STAT6-regulated protein(s) that must be synthesized de novo. Identification of a powerful extrahepatic regulatory enhancer for arginase I provides potential to manipulate arginase I activity in immune cells while sparing liver urea cycle function.

Animals↗
PubMed2002

Infection due to nontuberculous Mycobacterium other than MAC in AIDS patients at Siriraj hospital during 1998-2000: saprophyte vs pathogen.

HIV is a major health problem in Thailand. These patients are vulnerable to opportunistic infections, especially Mycobacterium tuberculosis and MAC infection. However, NTM was considered a rare disease in Thailand before the AIDS era. In this study, there were 38 HIV seropositive patients with NTM (other than MAC) identified from clinical specimens during the 3 year period 1998-2000 at Siriraj Hospital, which has a higher prevalence than the previous report. Among these patients, 29 cases were likely to have had definite infection from NTM, 5 cases possibly had NTM as a pathogen, and 4 cases had NTM as colonization. The most common site of infection was the lung (87%) and most common symptoms were cough (62.2%), fever (34.2%), weight loss (42.1%), and lymphadenopathy (5.3%). The outcome was poor because many NTM are not susceptible to standard medication for tuberculosis which is the empirical treatment for the majority of HIV seropositive patients with a clinical finding suspected of mycobacterial infection. The fatality rate was as high as 58.6 per cent. Awareness of NTM as a potential pathogen in HIV seropositive patientsand adjustment of medications even before the availability of culture results may improve the outcome of treatment of NTM infection in HIV seropositive patients.

AIDS-Related Opportunistic Infections↗
PubMed1994

The pathogenic role of acetylcholine receptor alpha chain epitope within alpha 146-162 in the development of experimental autoimmune myasthenia gravis in C57BL6 mice.

One of the dominant T cell epitopes in the acetylcholine receptor (AChR) alpha chain lies within the region 146-162 and has been implicated in the pathogenesis of experimental autoimmune myasthenia gravis (EAMG) in C57BL6 (B6) mice. To directly examine the pathogenic potential of alpha 146-162 in EAMG, B6 mice were primed with AChR in complete Freunds adjuvant (CFA) and subsequently boosted twice with either alpha 146-162 or a control peptide in CFA. Seventy percent of the mice boosted with alpha 146-162 developed muscle weakness characteristic of EAMG, while none of the mice boosted with the control peptide showed any clinical signs of the disease. Thus, the data provided evidence for epitope within AChR alpha 146-162 as one of the EAMG-inducing pathogenic epitopes in B6 mice.

Amino Acid Sequence↗
PubMed1993

Trichomonas vaginalis: strain differences in adhesion to plastic and virulence in vitro and in vivo.

Trichomonas vaginalis isolated from clinical cases were grown axenically in TYI-S-33 medium. Various strains of this flagellate showed different adhesion characteristics in medium containing bovine serum or Cohn fractions thereof. These were not inversely related to the time in axenic culture. The adsorption of serum components to the parasites was assessed in relationship to adhesion but in many cases was probably not adhesion-related. All strains tested for virulence in vitro were almost equally cytotoxic for HeLa tissue cultures. However, in infectivity trials, one of these strains exhibited the highest adhesion capability and proved to be the most virulent for mice, and another (cloned) strain with the poorest adhesion capability failed to cause infection. Other strains exhibited lessened virulence following their extended axenic cultivation. It therefore appears that the in vivo pathogenic potential of the parasites growing in axenic culture is inherently strain-dependent. The findings suggest that although adhesion in whole serum-containing medium is sufficient to differentiate between various Trichomonas isolates, it is insufficiently sensitive to correlate adhesion with virulence. It apparently is important to identify the adhesion-mediating factor(s) in serum or in its Cohn fractions IV-1 and IV-4 and to use it (them) to elucidate the possible correlation between the parasite's capacity to adhere and its pathogenicity.

Adsorption↗
PubMed1999

Pathology, diagnosis and epidemiology of the rodent Helicobacter infection.

Since the first isolation of Helicobacter pylori from humans in 1983, 18 Helicobacter species have been identified during the last decade in domestic and laboratory animals. Several Helicobacter species have been isolated from the gastrointestinal tracts of various mammalian species and birds. Helicobacter hepaticus, H. muridarum, H. bilis, H. rodentium and Flexispira rappini have been isolated from mice. Among these species, only H. hepaticos has been clearly recognized as a pathogen. Indeed, it displays the pathogenic potential to elicit hepatitis in several strains of mice; moreover in A/JCr mice, it is strongly associated with hepatic cancer. Among the five murine helicobacter species, apart from H. hepaticus, F. rappini has not been found associated with lesions, H. muridarum has been observed in gastric glands of mice with chronic gastritis, and H. bilis has been reported in the liver of mice with chronic hepatitis. When associated with H. rodentium, H. bilis is able to induce diarrhea in SCID mice. In no case has pathogenicity of a single species been clearly proven. In rats, H. trogontum and H. muridarum have been isolated from the intestine, without any information concerning their respective pathogenicity. H. cinaedi and H. cholecystus have been identified from the intestine and the gallbladders of hamsters, respectively. The diagnosis of Helicobacter species by polymerase chain reaction (PCR) is a rapid, specific and sensitive technique. One of the most promising diagnostic techniques of these infections seems to be the PCR detection of Helicobacter sp. from feces based on the 16S rRNA sequences, then a restriction enzyme analysis to identify the actual species. Several drug regimens have also been evaluated to eradicate H. hepaticus from mice. Helicobacter infections, particularly H. hepaticus and H. bilis, seem to be widespread in laboratory mouse colonies and have also been detected from commercial breeders.

Animals↗
PubMed2005

A millennium update on pediatric diarrheal illness in the developing world.

More than one billion diarrhea episodes occur every year among children younger than 5 years of age in socioeconomically developing countries causing 2 to 2.5 million deaths. More than twenty viral, bacterial, and parasitic enteropathogens are currently associated with acute diarrhea. Rotavirus and diarrheagenic Escherichia coli are the most common pathogens responsible for acute diarrhea episodes in children; Shigella spp., Salmonella spp, Campylobacter jejuni/coli, Vibrio cholerae, Aeromonas spp, and Plesiomonas spp. occur more commonly in poorer areas and infections caused by protozoa and helminthes occur mainly in areas where environmental sanitation is significantly deteriorated. Initial clinical assessment of a child with diarrhea should focus on obtaining an accurate evaluation of hydration and nutritional status. Assessment of stool characteristics (e.g., liquid non-bloody stools vs. dysenteric or bloody stools) is a key feature in determining potential pathogens causing an acute diarrhea episode. Diagnostic guidelines are discussed in the article. The major therapeutic intervention for all individuals with diarrhea consists of fluid and electrolyte therapy. When antimicrobial therapy is appropriate, selection of a specific agent should be made based upon susceptibility patterns of the pathogen or information on local susceptibility patterns. Current guidelines for administering appropriate antimicrobial treatment are provided in the article. Preventive measures include careful personal hygiene, especially promotion of hand washing. Immunizations currently or soon to be available for Salmonella serotype Typhi, cholera prevention, and rotavirus are discussed.

Acute Disease↗
PubMed2006

Molecular analysis of two uncharacterized sequence variants of the VHL gene.

Mutations in the VHL gene cause von Hippel-Lindau disease, a cancer predisposing syndrome characterized by a variety of benign and malignant neoplasms. We report the molecular characterization of two sequence variants of the VHL gene: a synonymous substitution c.462 A>C in exon 2 and a duplication of 11 bp in the promoter region (c.-65_-55dup11). The first variant is a pathogenic mutation because, although it does not change the sense of the affected codon, it causes skipping of exon 2 in the affected allele by altering the splicing consensus site at the 3' end of exon 2. The 11 bp duplication represents a nonpathogenic variant. In fact, although it affects a critical region of the VHL promoter, it was found in healthy controls, and we show that carrier individuals express both VHL alleles at equimolar levels. Our data underline the importance of careful evaluation of the potential pathogenicity of sequence variants that may not belong to the obvious disease-causing mutation categories, or that affect relevant regulatory regions. mRNA analysis will be required to ultimately resolve this issue.

Adolescent↗
PubMed1998

Irradiation as a method for decontaminating food. A review.

Despite substantial efforts in avoidance of contamination, an upward trend in the number of outbreaks of foodborne illnesses caused by nonsporeforming pathogenic bacteria are reported in many countries. Good hygienic practices can reduce the level of contamination but the most important pathogens cannot presently be eliminated from most farms nor is it possible to eliminate them by primary processing, particularly from those foods which are sold raw. Several decontamination methods exist but the most versatile treatment among them is the processing with ionizing radiation. Decontamination of food by ionizing radiation is a safe, efficient, environmentally clean and energy efficient process. Irradiation is particularly valuable as an endproduct decontamination procedure. Radiation treatment at doses of 2-7 kGy--depending on condition of irradiation and the food--can effectively eliminate potentially pathogenic nonsporeforming bacteria including both long-time recognized pathogens such as Salmonella and Staphylococcus aureus as well as emerging or "new" pathogens such as Campylobacter, Listeria monocytogenes or Escherichia coli O157:H7 from suspected food products without affecting sensory, nutritional and technical qualities. Candidates of radiation decontamination are mainly poultry and red meat, egg products, and fishery products. It is a unique feature of radiation decontamination that it can also be performed when the food is in a frozen state. With today's demand for high-quality convenience foods, irradiation in combination with other processes holds a promise for enhancing the safety of many minimally processed foods. Radiation decontamination of dry ingredients, herbs and enzyme preparations with doses of 3-10 kGy proved to be a viable alternative to fumigation with microbicidal gases. Radiation treatment at doses of 0.15-0.7 kGy under specific conditions appears to be feasible also for control of many foodborne parasites, thereby making infested foods safe for human consumption. Microorganisms surviving low- and medium-dose radiation treatment are more sensitive to environmental stresses or subsequent food processing treatments than the microflora of unirradiated products. Radiation treatment is an emerging technology in an increasing number of countries and more-and-more clearances on radiation decontaminated foods are issued or expected to be granted in the near future.

Animals↗
PubMed2026

Draft genome sequence of Enterococcus casseliflavus strain MBBL_MP4 isolated from healthy bovine milk.

We report the draft genome sequence of Enterococcus casseliflavus MBBL_MP4, recovered from healthy bovine milk. The 3.45-Mbp genome assembly comprises 27 contigs and indicates low pathogenic potential, with no acquired antimicrobial resistance or known virulence genes. This genome provides a valuable resource for the genomic characterization of bovine-associated E. casseliflavus.

Enterococcus casseliflavus↗
PubMed1999

Occurrence of Vibrio and other pathogenic bacteria in Mytilus galloprovincialis (mussels) harvested from Adriatic Sea, Italy.

Sixty-two samples of Mytilus galloprovincialis (mussels) harvested from approved shellfish waters in the Adriatic Sea were examined for the presence of Vibrio, Salmonella, Campylobacter, and verocytotoxin producing Escherichia coli. Vibrio spp. were isolated from 48.4% of samples; the species most frequently found were V. alginolyticus (32.2%) and V. vulnificus (17.7%), followed by V. cincinnatiensis (3.2%), V. parahaemolyticus (1.6%), V. fluvialis (1.6%) and V. cholerae non-O1 (1.6%). V. parahaemolyticus resulted negative to Kanagawa-phenomenon and to PCR amplification of tdh gene. V. cholerae resulted negative to PCR amplification of sto gene. No Salmonella, Campylobacter, or E. coli verocytotoxin-producing strains were isolated. The results of this study suggest the potential risk of ingesting raw or undercooked mussels due to the frequent presence of potentially pathogenic Vibrio species.

Animals↗