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PubMedDate not supplied

Nonsevere community-acquired pneumonia: correlation between cause and severity or comorbidity.

BACKGROUND: Community-acquired pneumonia frequently constitutes a nonsevere infection manageable at home. However, for these low-risk episodes, the epidemiological features have not been carefully analyzed. OBJECTIVES: To determine the cause of nonsevere community-acquired pneumonia and to investigate if a correlation exists between cause and severity or comorbidity. METHODS: During a 3-year period, all patients with nonsevere community-acquired pneumonia, according to the Pneumonia Patient Outcome Research Team prognostic classification (patients in groups 1-3), were included in the study. Causes were investigated through the following procedures: cultures of blood, sputum, and pleural fluid; serologic tests; and polymerase chain reaction methods to detect Streptococcus pneumoniae DNA in whole blood or Mycoplasma pneumoniae and Chlamydia pneumoniae DNA in throat swab specimens. RESULTS: Of 317 initially included patients, 247 were eligible for the study. A microbial diagnosis was obtained in 162 patients (66%), and the main pathogens detected were S pneumoniae (69 patients [28%]), M pneumoniae (40 patients [16%]), and C pneumoniae (28 patients [11%]). For the 58 patients in prognostic group 1, M pneumoniae was the most prevalent cause, and atypical microorganisms constituted 40 (69%) of the isolated agents. In contrast, for patients in prognostic groups 2 and 3, S pneumoniae was the leading agent, and a significant reduction of M pneumoniae cases and a greater presence of other more uncommon pathogens were observed. The existence of comorbid conditions was not a determining factor for particular causes. CONCLUSIONS: Among low-risk patients with community-acquired pneumonia, there was a certain correlation between severity and cause. In contrast, the existence of a comorbidity did not have a predictive causative value.

Adult↗

PubMed2004

The effect of circumcision status on periurethral and glanular bacterial flora.

INTRODUCTION: Circumcision is a historical operation which is still performed for different purposes. The aim of this study is to investigate the changes in periurethral and glanular sulcus flora due to circumcision to determine the role of circumcision on urinary tract infections (UTIs). PATIENTS AND METHODS: Fifty patients who were circumcised for social-religious reasons between January 2000 and January 2001 were evaluated in this prospective study. Two swabs were taken from the periurethral and glanular sulcus regions both just before circumcision and 4 weeks after, and the bacteria cultured were recorded. RESULTS: We isolated pathogenic bacteria in the periurethral region of 32 (64%) patients (enterococci in 14 cases; Escherichia coli in 12 cases) before circumcision, and this number decreased to 5 (10%) after circumcision. Similarly, pathogenic bacteria were cultured from the glanular sulcus swabs of 33 (68%) patients (enterococci in 14 cases; E. coli in 10 cases), as well as coagulase-negative staphylococci in another 15 patients before circumcision. Following circumcision, we detected pathogenic bacteria in the glanular cultures of only 4 cases, whereas 40 children had non-pathogenic skin flora. Only 1 of 5 children with history of UTIs (n = 1) and retractable phimosis (n = 4) had periurethral pathogenic bacteria (Proteus spp.) in the post-circumcision period. The differences between pre- and post-circumcision values of the pathogenic bacterial colonizations were statistically significant in both groups sampled (p < 0.05). CONCLUSION: Non-circumcised patients have similar pathogenic bacterial colonizations in the periurethral and the inner preputial regions, although they have no phimosis. The origin of periurethral flora should be the deeper preputial regions. The flora greatly changed with skin commensals after circumcision. Circumcision might be beneficial from this point of view.

Bacteria↗

PubMed2002

Porcine circovirus type 2 (PCV-2) coinfections in US field cases of postweaning multisystemic wasting syndrome (PMWS).

The prevalence of different pathogens detected in combination with porcine circovirus type 2 (PCV-2) was studied retrospectively in field cases of postweaning multisystemic wasting syndrome (PMWS) diagnosed at the Iowa State University Veterinary Diagnostic Laboratory, Ames, Iowa, between January 2000, and September 2001. The presence of PCV-2 antigen in lymphoid tissues and/or lung, demonstrated by immunohistochemistry, together with moderate to severe lymphoid depletion and/or granulomatous lymphadenitis, was used as the criteria for the diagnosis of PMWS. A total of 484 cases fulfilled these criteria. Most of the cases (294/369) of PMWS occurred in pigs between the ages of 8 and 18 weeks, with a peak at 10 weeks of age. Porcine reproductive and respiratory syndrome virus was detected in 51.9% of the cases, Mycoplasma hyopneumoniae in 35.5%, bacterial septicemia in 14.0%, bacterial pneumonia in 7.6%, swine influenza virus in 5.4%, and PCV-2 alone in 1.9%. In cases with bacterial septicemia the most frequently isolated pathogen was Streptococcus suis. In cases with bacterial pneumonia, Pasteurella multocida was the most prevalent.

Animals↗

PubMed1995

Evaluation of periodontal treatments using controlled-release tetracycline fibers: microbiological response.

In a 12-month multi-center study of 116 adult periodontitis subjects, six putative periodontal pathogens were monitored by DNA probe methods in a subset of 31 subjects. Monitored species included Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Eikenella corrodens (Ec), Campylobacter rectus (Cr), and Actinobacillus actinomycetemcomitans (Aa) with an average detection limit of 1.8 x 10(4) bacterial colony forming units/sample. The microbiological response to four periodontal treatments was studied, one treatment in each quadrant; scaling and root planing (S), scaling and root planing with tetracycline (TC) fiber (SF), a single application of TC fiber (F) and two serial applications of TC fiber (FF). Generally two sites were sampled in each quadrant, however, in some quadrants only one site was selected. These treatments were evaluated at baseline; immediately following therapy; and post-treatment at 1, 3, 6, and 12 months. The study was conducted with a split-mouth design with no maintenance therapy over a 12-month period. At baseline, 70.8% of sites had detectable Fn; 42.9% Pg; 63.5% Pi; 29.7% Ec; 28.3% Cr; and 5.5% Aa. No significant differences were seen in baseline proportions of these species between centers. Numbers and proportions of detectable pathogens (with the exception of Pg) exhibited a triphasic temporal response: a precipitous initial decrease immediately following therapy; a rise in proportions in the 1- to 3-month post-therapy period; and a spontaneous decline in the absence of therapy over the 3- to 12-month period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2002

[Acute Gastroenteritis in hospitalized children. 14-Year evolution].

OBJECTIVES: To analyze the etiology and evolution of patients with acute gastroenteritis hospitalized in our pediatric department and to study the clinical and laboratory differences between acute viral and bacterial gastroenteritis. PATIENTS AND METHODS: We studied the children with a diagnosis of acute gastroenteritis, aged between 0 and 14 years, who were consecutively admitted between 1987 and 2000. Differences were considered statistically significant if p < 0.05. RESULTS: A total of 2,613 patients diagnosed with acute gastroenteritis were hospitalized (10.4 % of hospital admissions). The most common pathogens isolated were rotaviruses (46.5 %), followed by Salmonella (32.6 %) and Campylobacter (19.3 %). Hospital admissions due to Salmonella (p < 0.0001), other bacteria (Escherichia coli and Shigella) (p < 0.002) and adenoviruses (p < 0.01) significantly decreased. Rotaviruses were the most frequently detected pathogens in winter and in children aged less than 1 year (p < 0.0001). The incidence of Salmonella spp was greater in summer and in children older than 2 years (p < 0.0001). The incidence of hyperthermia (rectal temperature higher than 38.5 degreeC) (p < 0.0001), dehydration (p < 0.0005) and fecal blood (p < 0.0001) was higher in bacterial diarrheas. Erythrocyte sedimentation rate (p < 0.001) and leukocyte counts were higher in bacterial gastroenteritis (p < 0.01). CONCLUSIONS: Rotaviruses were the most frequently isolated enteropathogens. The features that best distinguished between bacterial and viral diarrhea were hyperthermia and fecal blood. Hospital admissions due to Salmonella Shigella E. coli, and adenoviruses significantly decreased.

Acute Disease↗

PubMed2001

Identification of virulence attributes of gastrointestinal Escherichia coli isolates of veterinary significance.

The pathogenic strains of Escherichia coli recovered from the intestinal tract of animals fall into categories called enterotoxigenic, enteropathogenic, enterohemorrhagic and necrotoxigenic. The other two categories, enteroinvasive and enteroaggregative, have not been reported in animals. The pathogenicity of these strains is determined by the presence of certain genes that encode adhesins and toxins, are generally organized in large blocks in chromosomes, large plasmids or phages, and are often transmitted horizontally between strains. In this review, we summarize current knowledge of the virulence attributes that determine the pathogenic potential of E. coli strains and the methods available to assess the virulence of the strains. We also discuss the clinical symptoms, the gross and histological lesions, and the molecular diagnostic methods our laboratories have implemented for detecting pathogenic strains of E. coli that are isolated from the gastrointestinal tract of animals.

Adhesins, Escherichia coli↗

PubMed1999

[Study on etiology of nongonococcal urethritis].

One thousand one hundred and fifty-seven samples from urogenital tract were detected by isolating culture and immunofluorescence. The positive rates of Chlamydia trachomatis (CT), Ureaplasma Urealyticum (UU), Mycoplasma hominis (Mh), Candida (Cd), Staphylococcus aureus were 27.8%, 33.5%, 25.6%, 11.5%, 23% respectively. The rate of mixed infection caused by at least two pathogens was 19.8%. About 90% of the infected patients were from 20 to 40 years old. The related factors of pathogen detection were also studied.

Adolescent↗

PubMedDate not supplied

[Toll type receptors: molecular bases of the relationship between innate and adaptation responses of the immune system].

Microbes have on their surface molecular patterns that are common among a broad range of pathogens. These patterns are recognized by a wide variety of cellular receptors, the most important of which are a family of transmembrane proteins termed "Toll-like receptors" (TLR). TLRs are pattern-recognition receptors that have key roles in detecting pathogens and initiating inflammatory responses. The receptor of Gram negative bacterial LPS, TLR4, is the best characterized member of the TLR family. So far, ten mammalian toll-like receptors (TLR1-TLR10) have been identified. Recent studies revealed that the TLR signaling pathway is a critical mediator of sepsis. An understanding of TLRs and their signaling pathway will reveal a therapeutic target in sepsis and other immune mediated diseases.

Animals↗

PubMed2005

CATERPILLER: a novel gene family important in immunity, cell death, and diseases.

The newly discovered CATERPILLER (CLR) gene family encodes proteins with a variable but limited number of N-terminal domains, followed by a nucleotide-binding domain (NBD) and leucine-rich repeats (LRR). The N-terminal domain consists of transactivation, CARD, Pyrin, or BIR domains, with a minority containing undefined domains. These proteins are remarkably similar in structure to the TIR-NBD-LRR and CC-NBD-LRR disease resistance (R) proteins that mediate immune responses in plants. The NBD-LRR architecture is conserved in plants and vertebrates, but only remnants are found in worms and flies. The CLRs regulate inflammatory and apoptotic responses, and some act as sensors that detect pathogen products. Several CLR genes have been genetically linked to susceptibility to immunologic disorders. We describe prominent family members, including CIITA, CARD4/NOD1, NOD2/CARD15, CIAS1, CARD7/NALP1, and NAIP, in more detail. We also discuss implied roles of these proteins in diversifying immune detection and in providing a check-and-balance during inflammation.

Animals↗

PubMed2005

Deletions account for 17% of pathogenic germline alterations in MLH1 and MSH2 in hereditary nonpolyposis colorectal cancer (HNPCC) families.

Hereditary nonpolyposis colorectal cancer (HNPCC) is due to defects in DNA mismatch repair (MMR) genes MSH2, MLH1, MSH6, and to a lesser extent PMS2. Of 466 suspected HNPCC families, we defined 54 index patients with either tumors of high microsatellite instability (MSI-H) and/or loss of expression for either MLH1, MSH2, and/or MSH6, but without a detectable pathogenic point mutation in these genes. This study cohort was augmented to 64 patients by 10 mutation-negative index patients from Amsterdam families where no tumors were available. Deletion/duplication screening using the multiplex ligation-dependent probe amplification (MLPA) revealed 12 deletions in MSH2 and two deletions in MLH1. These deletions constitute 17% of pathogenic germline alterations but elucidate the susceptibility to HNPCC in only 22% of the mutation-negative study cohort, pointing towards other mutation mechanisms for an inherited inactivation of MLH1 or MSH2. We describe here four novel deletions. One novel and one known type of deletion were found for three and two unrelated families, respectively. MLPA analysis proved a reliable method for the detection of genomic deletions in MLH1 and MSH2; however, sequence variations in the ligation-probe binding site can mimic single exon deletions.

Alu Elements↗

PubMed1989

Diagnostic studies of nosocomial diarrhea in children: assessing their use and value.

During a 17-month period (01/11/85-05/31/86) 225 cases of nosocomial diarrhea were identified in a children's hospital. Diarrhea was considered to be nosocomial if it began at least 72 hours after the patient's hospital admission or within 3 days after discharge. One or more routine diagnostic studies for identification of a pathogen were performed in 195 (87%) cases. The most commonly performed test was the bacterial stool culture. None of these samples yielded a bacterial pathogen. The only pathogens detected by routine laboratory studies were rotavirus (61/137 [45%] samples were positive for rotavirus by ELISA) and Clostridium difficile (9/54 [17%] positive for toxin). Of the patients whose tests were positive for rotavirus 56 were younger than 2 years of age, and all were identified in the winter and spring. When multiple stool samples were tested by the diagnostic laboratory, rotavirus was identified in an additional 14 patients whose initial stool samples were negative for rotavirus. All patients whose tests were positive for C. difficile toxin had received antibiotics within the previous 3 months. Ova/parasites were not detected in 53 of the tested stools. We also identified enteric adenovirus in six patients. Viruses were identified in 95 (42%) of the 225 cases of nosocomial gastroenteritis. Nosocomial diarrhea is common in a children's hospital. Rotavirus is the most commonly identified pathogen. Rotavirus testing is valuable in children with nosocomial diarrhea who are younger than 2 years of age, especially in the winter and spring. Multiple samples may be necessary to identify rotavirus. C. difficile toxin assay should be considered for patients who are receiving or who have received antibiotics.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross Infection↗

PubMed2005

PCR and oligonucleotide array for detection of Enterobacter sakazakii in infant formula.

Enterobacter sakazakii has been implicated in a several form of neonatal meningitis with a high mortality rate. In the present study, the species-specific PCR and oligonucleotide array assays were developed to detect the 16S-23S rDNA internal transcribed spacer (ITS) of E. sakazakii. Two pairs of specific PCR primers and 10 oligonucleotide probes were designed by sequencing the ITS of six strains of E. sakazakii and BLAST of GenBank. The specificity and efficiency of the PCR and oligonucleotide array methods were tested against a panel of numerous strains from 88 different bacterial strains. All of the E. sakazakii strains generated positive signal, and no cross-reaction was observed with non-E. sakazakii strains in the PCR and oligonucleotide array detections based on ITS sequences. Sensitivity of the detections is 1.3 CFU/100 g infant formula with the selective enrichment. Both of the PCR and oligonucleotide array procedures take only 48 h including the enrichment culture, whereas the conventional methods required at least 5 days. This study demonstrated that both of the pathogenic detections are time-saved and reliable.

Cronobacter sakazakii↗

PubMed2002

Distribution patterns of Escherichia coli O157:H7 in ground beef produced by a laboratory-scale grinder.

This study determined the distribution patterns of Escherichia coli O157:1H7 in ground beef when a contaminated beef trim was introduced into a batch of uncontaminated beef trims prior to grinding in a small-scale laboratory grinder. A beef trim (15.3 +/- 2 g) was inoculated with a rifampicin-resistant strain of E. coli O157:H7 (E. coli O157:H7rif) and introduced into a stream of noncontaminated beef (322 +/- 33 g) prior to grinding. Seven inoculum levels (6, 5, and 4 total log CFU [high]; and 3, 2, 1, and 0 total log CFU [low]) were studied in triplicate. E. coli O157:H7rif was not detected in 3.1 to 43% of the ground beef inoculated with the high levels or in 3.4 to 96.9% of the ground beef inoculated with the low levels. For all inoculum levels studied, the five ground beef fractions (each 7.8 +/- 0.6 g) with the highest pathogen levels accounted for 59 to 100% of the total pathogens detected. For all inoculum levels, there was a linear relationship between the quantity of ground beef containing E. coli O157:H7rif and the inoculum level. The quantity of E. coli O157:H7rif in the beef remaining in the grinder was proportional to the inoculum level and was related to the location in the grinder. Different components of the grinder accumulated E. coli O157:H7rif in different quantities, with the most significant accumulation being in the nut (collar) that attaches the die to the blade. This study determined specific distribution patterns of E. coli O157:H7rif after the grinding of a contaminated beef trim along with uncontaminated trims, and the results indicate that the grinding operation should be regarded as a means of distribution of microbial contamination in risk analyses of ground beef operations.

Animals↗

PubMed2003

Prevalence and pathogenic role of Cyclospora cayetanensis in a Venezuelan community.

The prevalence and pathogenic role of Cyclospora cayetanensis among 212 subjects (age range = two months to 70 years) in an impoverished community in Venezuela were assessed retrospectively. For identification of the coccidium, modified Ziehl-Neelsen carbolfuchsin staining of formalin-ether concentrates was used. For other pathogenic parasites, iron-hematoxylin-stained smears and formalin-ether concentrates were examined. Cyclospora infections were identified in 13 (6.1%) subjects with a high percentage of asymptomatic carriers (11 of 13, 84.6%). Only two (15.4%) infants had diarrhea and the coccidium as the single detectable pathogenic parasite. The findings suggest that Cyclospora infections are relatively common and often asymptomatic in this region.

Adolescent↗

PubMed1999

THE THREE DS OF PCR-BASED GENOMIC ANALYSIS OF PHYTOBACTERIA: Diversity, Detection, and Disease Diagnosis.

The advent of molecular biology in general and the polymerase chain reaction in particular have greatly facilitated genomic analyses of microorganisms, provide enhanced capability to characterize and classify strains, and facilitate research to assess the genetic diversity of populations. The diversity of large populations can be assessed in a relatively efficient manner using rep-PCR-, AFLP-, and AP-PCR/RAPD-based genomic fingerprinting methods, especially when combined with computer-assisted pattern analysis. Genetic diversity maps provide a framework to understand the taxonomy, population structure, and dynamics of phytobacteria and provide a high-resolution framework to devise sensitive, specific, and rapid methods for pathogen detection, plant disease diagnosis, as well as management of disease risk. A variety of PCR-based fingerprinting protocols such as rDNA-based PCR, ITS-PCR, ARDRA, T-RFLPs, and tRNA-PCR have been devised, and numerous innovative approaches using specific primers have been adopted to enhance both the detection and identification of phytobacteria. PCR-based protocols, combined with computer-based analysis, have provided novel fundamental knowledge of the ecology and population dynamics of bacterial pathogens, and present exciting new opportunities for basic and applied studies in plant pathology.

Journal Article↗

PubMed2003

Standardization of diagnostic PCR for the detection of foodborne pathogens.

In vitro amplification of nucleic acids using the polymerase chain reaction (PCR) has become, since its discovery in the 1980s, a powerful diagnostic tool for the analysis of microbial infections as well as for the analysis of microorganisms in food samples. However, despite its potential, PCR has neither gained wide acceptance in routine diagnostics nor been widely incorporated in standardized methods. Lack of validation and standard protocols, as well as variable quality of reagents and equipment, influence the efficient dissemination of PCR methodology from expert research laboratories to end-user laboratories. Moreover, the food industry understandably requires and expects officially approved standards. Recognizing this, in 1999, the European Commission approved the research project, FOOD-PCR (http://www.PCR.dk), which aims to validate and standardize the use of diagnostic PCR for the detection of pathogenic bacteria in foods. The present review focuses on the harmonization procedure and standardization criteria for detection of foodborne pathogens by PCR. The progress of standardization so far and future perspectives of diagnostic PCR are discussed.

Bacteria↗

PubMed1994

[Etiology, diagnosis and course of infectious diarrhea in the Liestal canton hospital (5-year retrospective study)].

Between 1987 and 1991 219 patients (1.3% of all hospitalized patients) with acute infectious diarrhea were investigated retrospectively. 52% of the patients were hospitalized and 48% were outpatients. In 55% the inducing diarrhea microorganism could be identified. The most frequently detected pathogens were endemic Salmonella sp. and Campylobacter jejuni (65%). Imported diarrheas (Shigella sp. and parasites) were rare, as only 15% of the patients had a history of travel. All Clostridium difficile infections were associated with antibiotic treatment. The stool examinations for bacteria were positive in 92/160 patients (57%). Stool examinations for occult blood or fecal leukocytes were highly useful in detecting the infectious agent. In 70% of the patients with positive occult blood test or 81% of the patients with fecal leukocytes, an infectious agent in the stool was found. All patients recovered with few complications. 31% of the patients were treated by antibiotics because of septic disease or pathogenic parasites.

Adolescent↗

PubMed2005

[Microbiological diagnosis of urinary tract infections].

Definitive diagnosis of urinary tract infection (UTI) is performed through quantitative urine culture. Traditionally the presence of 100,000 or more bacteria/ml in urine has been considered to represent significant bacteriuria, indicating UTI. However, this criterion is only applicable to certain population groups and cannot currently be considered an absolute criterion. The "real" presence of any number of bacteria in urine can represent a UTI when there are specific symptoms and pyuria. In the last few years various automatic systems have been introduced onto the market which, by adapting classical diagnostic techniques, allow the presence of a UTI to be rapidly ruled out, although their clinical utility is controversial. In addition, the new chromogenic culture media allow direct identification of uropathogens and, in particular, are of enormous help in the detection of polymicrobial cultures. Likewise, automatic systems can provide results on identification and sensitivity to be obtained in a single day. However, because new phenotypes of resistance are continually appearing, the antibiogram model used with classical uropathogens has had to be modified, requiring special techniques for pathogen detection and characterization. Correct interpretation of the antibiogram in these cases is essential to detect these phenotypes and achieve therapeutic success.

Adult↗