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PubMed2006

Concordance of antibiotic prophylaxis, direct Gram staining and protected brush specimen culture results for postoperative patients with suspected pneumonia.

BACKGROUND AND OBJECTIVES: Antibiotic therapy alters the diagnostic value of protected brush specimens. With protected brush specimens alone, diagnosing pneumonia requires 24 or 48 h. Addition of direct Gram staining shortens this delay. Antibiotic prophylaxis, recommended after major surgery, may influence the contribution of Gram staining to diagnosing postoperative pneumonia. METHODS: During a 1-yr period, we retrospectively studied all patients on mechanical ventilation suspected of having postoperative pneumonia who had undergone fibreoptic bronchoscopy with protected brush specimens. Postoperative pneumonia was diagnosed when quantitative protected brush specimens culture results yielded 103 colony-forming units mL-1. RESULTS: Fifty patients were clinically suspected of having postoperative pneumonia after cardiac (n=42), vascular (n=5) or thoracic (n=3) surgery. Eleven (22%) samples were obtained during antibiotic prophylaxis. Twenty-two (44%) episodes were microbiologically proven. Gram-stain sensitivity was 95.5%, with 82.1% specificity, 80.7% positive-predictive value and 95.8% negative-predictive value. Concordance between direct Gram-stain-identified pathogens and Gram stain of cultured pathogens was significantly less frequent during antibiotic prophylaxis (63.6%) than afterwards (94.9%) (P<0.05). CONCLUSION: Antibiotic prophylaxis diminished the diagnostic value of Gram staining of protected brush specimens. When protected brush specimens was performed during antibiotic prophylaxis, Gram staining accurately enabled early exclusion of postoperative pneumonia because of its excellent negative-predictive value. After antibiotic prophylaxis, Gram staining permitted early diagnosis of postoperative pneumonia identification of the responsible pathogen.

Aged↗
PubMedDate not supplied

[Bacteriological examination of the sputum in support of a rational antibiotic therapy of bronchopulmonary infections].

An algorhythm of bacteriological investigation of the sputum is suggested for the etiological diagnosis of acute bronchopulmonary infections with pathogenically-conditioned bacteria. This investigation avoids misleading results, and provides, in a minimal time interval, both the first empiric criteria for the application of antibiotherapy--a definition of the microscopy category of the infecting pathogenically-conditioned bacteria--, and the second one, namely the antibiogram of the primary culture. This algorhythm is based on: decontamination of the sample by repeated washings; microscopical screening of the sample's quality, according to the ratio between inflammatory cells, squamous epithelial cells and the fibrin exudate; the qualitative bacterioscopic examination; the semi-quantitative culture of the sputum with the antibiogram on the primary culture; identification of infecting pathogenically-conditioned bacteria by confrontation of the microscopic significant amounts; inflammatory cells on the smear prepared directly from the sputum; the antibiogram on sub-cultures of the infecting, pathogenically-conditioned bacteria. Of high significance for the etiologic implication is the association of the inflammatory cells in quantities equal or greater than 13 organisms per microscopic field of pneumoncocoid bacteria, equal or greater than 20 organisms per microscopic field of the haemophilloid germs (with a significance threshold of 5%), and equal or greater than 18 organisms per microscopic field of neisseroid germs (at a significance threshold of 0.27%).

Anti-Bacterial Agents↗
PubMed2006

TLRs, NLRs and RLRs: a trinity of pathogen sensors that co-operate in innate immunity.

Significant advances in our understanding of innate immunity have been made following the identification of three families of pathogen sensors: Toll-like receptors (TLRs), NOD-like receptors (NLRs) and RIG-I-like receptors (RLRs). Members of the TLR family recognize bacteria, viruses, fungi and protozoa; NLRs with known functions detect bacteria, and RLRs are anti-viral. It is likely that interplay between these families ensures the efficient co-ordination of innate immune responses, through either synergistic or co-operative signalling. Important interactions occur between TLRs and certain NLRs for inducing the pro-inflammatory cytokine interleukin (IL)-1beta. TLRs induce pro-IL-1beta production and prime NLR-containing multi-protein complexes, termed "inflammasomes", to respond to bacterial products and products of damaged cells. This results in caspase-1 activation and the subsequent processing of pro-IL-1beta to its active form. In this article, we hypothesize that during the first phase of the host response to infection, an important interplay occurs between these families, providing a substantial combinatorial repertoire in innate immunity.

Adaptor Proteins, Signal Transducing↗
PubMed1999

[The observation of mycology and clinical efficacy in 325 cases with otomycosis].

OBJECTIVE: To study otomycosis of pathogenic fungi, antifungal susceptibility test and clinical efficacy. METHOD: The study was performed as follows: 1) culture of pathogenic fungi and fungus identification in 110 cases. 2) antifungal susceptibility test with Etest strip by ketoconazole (KE), itraconazole (IT), Fluconazole (FC), Fluorocytosine (FL), and amphotericinum B (AP). 3) Topical application of doktarin ps cream (DC), ketoconazole cream (KEC), clotrimazole ung (CU), and thymol alcohol (TA) were performed in 4 groups and the intermittent impulsive treatment in who failed to respond to local treatment were performed too. RESULT AND CONCLUSION: 1) Chiefly, otomycosis of pathogenic fungi were aspergillus (79%) and candida albicans (8%) and penicillium citrinum (5%). 2) Antifungal susceptibility test showed that aspergillus were sensitive to KE and IT, but not sensitive to KE and FL, and candida albicans were sensitive to KE, IT, FC, FL and AP all; P. citrinum was sensitive to AP, FL and KE but not to FC. 3) Effective rate of topical application on 4 groups were 97.6%, 97.5%, 90.0% and 80.0% respectively. Comparing the results between compound azoles drugs and TA, there was a statistical significant difference (P < 0.05), the efficacy of compound azoles is better than that of TA. The effective rate of systematic intermittent impulsive treatment in 30 cases failed to respond to local treatment were 100%.

Adolescent↗
PubMed1996

Spinal infections in the immunocompromised host.

There is an increasing population of immunocompromised patients with HIV, IV drug abuse, organ transplantation, and long-term steroid treatment developing spinal infections. Delayed diagnosis because of blunted host immune response and lack of outward signs and symptoms places the treating physician at a disadvantage in the treatment of this type of disease, which presents at a later stage of development. Immunocompromised patients are infected by a different group of pathogens than their healthier cohorts (e.g., Pseudomonas, gram-negative bacteria and fungal infections) because their host defenses are diminished. Osteomyelitis with or with out pyomyositis and epidural abscess may occur. The overriding symptom is back pain. Radiculopathy, myelopathy, and sensory loss may accompany local pain and tenderness. Plain film radiography, CT scan, MR image, and bone scan is invaluable in the diagnosis of these infections. The cornerstone of treatment is identification of the responsible pathogen, appropriate medical therapy, immobilization of the affected segment of the spine, and physical therapy to combat physical deconditioning. Psoas abscesses may require surgical debridement if they cannot be adequately drained by CT-guided percutaneous catheterization. Epidural abscesses with neurologic compromise require surgical drainage. Impingement of the spinal cord or cauda equina by collapsed osteomyelitic vertebral bodies requires surgical debridement by anterior vertebrectomy, with an autologous tricortical iliac crest strut and immobilization of the spine using external bracing or posterior instrumentation as dictated by the disease.

Abscess↗
PubMed2003

Oxazolidinone structure-activity relationships leading to linezolid.

The development of bacterial resistance to currently available antibacterial agents is a growing global health problem. Of particular concern are infections caused by multidrug-resistant Gram-positive pathogens which are responsible for significant morbidity and mortality in both the hospital and community settings. A number of solutions to the problem of bacterial resistance are possible. The most common approach is to continue modifying existing classes of antibacterial agents to provide new analogues with improved attributes. Other successful strategies are to combine existing antibacterial agents with other drugs as well as the development of improved diagnostic procedures that may lead to rapid identification of the causative pathogen and permit the use of antibacterial agents with a narrow spectrum of activity. Finally, and most importantly, the discovery of novel classes of antibacterial agents employing new mechanisms of action has considerable promise. Such agents would exhibit a lack of cross-resistance with existing antimicrobial drugs. This review describes the work leading to the discovery of linezolid, the first clinically useful oxazolidinone antibacterial agent.

Acetamides↗
PubMed2002

[Use of MPO chromogenic culture medium for routine processing of urine cultures].

BACKGROUND: The chromogenic culture medium, MPO, was compared to culture on CLED (cystein, lactose, electrolyte-deficient) agar for the detection, enumeration and identification of urinary tract pathogens. METHODS: A total of 1,080 clinical urine specimens were assessed. All samples were inoculated in MPO and CLED using the calibrated loop method. RESULTS: Among 145 positive urine samples, 171 strains of bacteria were isolated (111 Escherichia coli, 26 Enterococcus spp., 12 Proteus spp., 10 Enterobacteriaceae from the Klebsiella-Enterobacter-Serratia group, 5 Pseudomonas aeruginosa, 4 Streptococcus agalactiae, 3 Staphylococcus spp. and 4 Candida albicans. For all samples, enumeration of microorganisms was comparable with the two media studied. Identification was also similar, except for 6 cases in which Enterococcus spp. were only detected with the chromogenic medium. CONCLUSIONS: Overall urine culture results with MPO chromogenic medium were similar to those obtained with CLED, making it a feasible alternative to the standard medium. Moreover, use of a chromogenic technique implies a significant reduction in workload, since additional tests to identify the microorganisms isolated are not needed in most cases.

Bacteria↗
PubMed1995

Rapid and sensitive PCR detection of Vibrio trachuri pathogenic to Japanese horse mackerel (Trachurus japonicus).

A polymerase chain reaction (PCR) method was performed for rapid and sensitive detection of pathogenic Vibrio trachuri isolated from cultured Japanese horse mackerel. A set of primers was selected from the base sequence of the Pst I fragment of T9210 chromosomal DNA and used for PCR detection of T9210. This PCR specifically amplified the DNAs from V. trachuri T9210, T9213, and T9216 but not of those other bacterial strains. PCR using a Pst I-1 primer set made it possible to detect 100 fg of T9210 DNA. The PCR method reported here may be useful for detection and identification of V. trachuri pathogenic to Japanese horse mackerel.

Animals↗
PubMed2001

Candida dubliniensis at a cancer center.

Candida dubliniensis, a germ tube-positive yeast first described and identified as a cause of oral candidiasis in patients with acquired immunodeficiency syndrome in Europe in 1995, has an expanding clinical and geographic distribution that appears to be similar to that of the other germ tube-positive yeast, Candida albicans. This study determined the frequency, clinical spectrum, drug susceptibility profile, and suitable methods for identification of this emerging pathogen at a cancer center in 1998 and 1999. Twenty-two isolates were recovered from 16 patients with solid-organ or hematologic malignancies or acquired immunodeficiency syndrome. Two patients with cancer had invasive infection, and 14 were colonized with fungus or had superficial fungal infection. All isolates produced germ tubes and chlamydospores at 37 degrees C, did not grow at 45 degrees C, and gave negative reactions with d-xylose and alpha-methyl-d-glucoside in the API 20 C AUX and ID 32 C yeast identification systems. Phenotypic identification was confirmed by molecular beacon probe technology. All isolates were susceptible to the antifungal drugs amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, and ketoconazole.

Adult↗
PubMed2002

A proposed serotyping system for Flavobacterium psychrophilum.

AIMS: To develop a common serological system for rapid and routine identification of the fish pathogen Flavobacterium psychrophilum. METHODS: Thirty-four isolates of Fl. psychrophilum from different fish species and different geographical areas were typed using a slide agglutination test and an enzyme-linked immunosorbent assay (ELISA). RESULTS: Seven host-dependent serovars (1: salmon; 2: trout; 3: trout; 4: eel; 5: carp; 6: tench; 7: ayu) were found. Serovar 2 was divided into two antigenic subgroups (2a and 2b). The results achieved by both slide agglutination and ELISA methods were totally consistent with each other. Although both techniques proved to be simple to carry out and useful, only the ELISA allowed identification of Fl. psychrophilum serovars using unabsorbed antiserum and whole-cells as antigens. SIGNIFICANCE AND IMPACT OF THE STUDY: This paper proposes a harmonized scheme for serological identification of Fl. psychrophilum to be used for diagnostic and seroepidemiological studies of the diseases it causes.

Animals↗
PubMed2004

Discovering new pathogens: culture-resistant bacteria.

Recent advances in gene-amplification technology and molecular phylogenetics have provided the means of detecting and classifying bacteria directly from their natural habitats without the need for culture. These techniques have revolutionized environmental microbiology, and it is now apparent that the global diversity of microorganisms is much greater than previously thought. In the context of clinical microbiology, this molecular-based approach has facilitated the characterization of culture-resistant bacteria associated with human disease. Examples include Helicobacter heilmannii, a cause of gastritis, Tropheryma whippeli (the agent of Whipple's disease), and the agents of human ehrlichiosis and bacillary angiomatosis. Molecular-based techniques also provide a means of investigating complex bacterial flora within the human ecosystem, such as feces and dental plaque, without the bias of culture-based isolation. This has given a new perspective to the study of polymicrobial infections such as gingivitis, and offers the potential for the detection and identification of novel bacterial pathogens from among complex and numerous endogenous microbial flora.

Bacteria↗
PubMed2002

Identification of Staphylococcus aureus exotoxins by combined sodium dodecyl sulfate gel electrophoresis and matrix-assisted laser desorption/ ionization-time of flight mass spectrometry.

Staphylococcus aureus is an important human pathogen whose pathogenesis involves the synthesis of cell wall associated virulence factors and secreted toxins with damaging effects on the host cells. Most of these pathogenic factors are synthesized in a growth-phase dependent manner as a response to environmental stress like heat, lack of nutrients or other deleterious conditions. Conventional identification of these pathogenic factors is based on Western blot analysis or enzyme-linked immunosorbent assay (ELISA) and is limited by the commercial availability of antibodies against these toxins. We report here the use of matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry for monitoring the pathogenic factors of S. aureus. For the identification of pathogenic factors, a methicillin sensitive strain of S. aureus, ATCC-29213, was grown at 37 degrees C or 42 degrees C in brain-heart infusion broth and harvested during the early stationary phase of growth. Secreted proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, enzymatically digested with trypsin and analyzed by MALDI-TOF mass spectrometry. When grown at 42 degrees C, alpha- and beta-hemolysins were found to accumulate in S. aureus supernatants while the concentration of protein A was slightly decreased. The identity of some of these toxins was confirmed by Western-blot analysis. MALDI-TOF mass spectrometry combined with sodium dodecyl sulfate gel electrophoresis represents a rapid and simple approach to characterize the virulence of S. aureus strains which seems to be particularly valuable for the identification of S. aureus exotoxins for which ELISA is not established.

Blotting, Western↗
PubMed2003

Immusorba TR and PH.

Immusorba TR (IM-TR) and PH (IM-PH) were developed as adsorbents with non-biological materials as affinity ligands to remove pathogenic autoantibodies. The adsorbents of IM-TR and IM-PH are polyvinyl alcohol gel immobilized with tryptophan and phenylalanine as ligand, respectively. IM-TR is clinically applied for treatment of autoimmune neurological diseases such as myasthenia gravis and Guillain-Barre syndrome. IM-PH is used for not only neurological diseases such as GBS and multiple sclerosis but also collagen diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). As many autoantibodies with different specificities have been found to have similar affinities to the ligand of Immusorba, it is expected that Immusorba will be applied to more diseases and contribute to the clarification of the mechanisms of the development of diseases by the identification of adsorbed unknown pathogenic substances with Immusorba.

Absorption↗
PubMed2005

Epidemiology of community-acquired pneumonia in adult patients at the dawn of the 21st century: a prospective study on the Mediterranean coast of Spain.

This study presents data from a prospective study of adult patients with community-acquired pneumonia (CAP). Of 493 patients included in the study, 223 (45.2%) were aged > or = 65 years, and 265 (53.7%) had one or more underlying diseases, mostly chronic obstructive pulmonary disease, diabetes mellitus or dementia. In total, 281 microorganisms were identified in 250 (50.7%) patients, with two or more pathogens detected in 28 (5.7%) cases. Microbial diagnosis varied according to age, severity, co-morbidity and site-of-care, but there was much overlap among groups. Streptococcus pneumoniae was the single most prevalent organism in outpatients, patients admitted to hospital, and patients who died, either as a single pathogen or combined with another organism. Infections caused by 'atypical' pathogens were seen across all groups, including the elderly and patients with co-morbidities. Mortality varied according to the pneumonia severity index (PSI) of the pneumonia patient outcomes research team. Shock (OR 34.48), an age of > 65 years (OR 25) and altered mental status (OR 9.92) were factors associated independently with 30-day mortality. Key findings from this study were the advanced age of the population with CAP, and the high prevalence of dementia as an underlying disease. The study also revealed that microbiological diagnosis of CAP remains problematic. Although certain epidemiological features may help to predict the microbial aetiology, the overlap among groups reduces the usefulness of this information in guiding therapeutic decisions. Greater effort should be made to improve identification methods for microbial pathogens causing CAP.

Adolescent↗
PubMed2002

Detection of protozoan parasites and microsporidia in irrigation waters used for crop production.

The occurrence of human pathogenic parasites in irrigation waters used for food crops traditionally eaten raw was investigated. The polymerase chain reaction was used to detect human pathogenic microsporidia in irrigation waters from the United States and several Central American countries. In addition, the occurrence of both Cryptosporidium oocysts and Giardia cysts was determined by immunofluorescent techniques. Twenty-eight percent of the irrigation water samples tested positive for microsporidia, 60% tested positive for Giardia cysts, and 36% tested positive for Cryptosporidium oocysts. The average concentrations in samples from Central America containing Giardia cysts and Cryptosporidium oocysts were 559 cysts and 227 oocysts per 100 liters. In samples from the United States, averages of 25 Giardia cysts per 100 liters and <19 (average detection limit) Cryptosporidium oocysts per 100 liters were detected. Two of the samples that were positive for microsporidia were sequenced, and subsequent database homology comparisons allowed the presumptive identification of two human pathogenic species, Encephalitozoon intestinalis (94% homology) and Pleistophora spp. (89% homology). The presence of human pathogenic parasites in irrigation waters used in the production of crops traditionally consumed raw suggests that there may be a risk of infection to consumers who come in contact with or eat these products.

Animals↗
PubMed1996

Comparison of polymerase chain reaction and culture methods for detection of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in subgingival plaque samples.

In this study, the major periodontal pathogens Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were detected in subgingival plaque samples from patients with periodontal disease by polymerase chain reaction (PCR) and conventional culture methods. 170 plaque samples from 43 patients were analysed; A. actinomycetemcomitans and P. gingivalis were each detected in 40 (24%) of samples by PCR, whereas conventional culture methods detected A. actinomycetemcomitans and P. gingivalis in 25 (15%) and 18 (11%) of samples, respectively. The proportion of patients carrying A. actinomycetemcomitans in at least 1 sampled periodontal site was 17/43 (40%) by PCR and 13/43 (30%) by culture; for P. gingivalis this was 12/43 (28%) by PCR and 9/43 (21%) by culture. Only 5 samples, from 3 patients, harboured both A. actinomycetemcomitans and P. gingivalis. It is concluded that PCR is more accurate than conventional culture methods for identification of these periodontal pathogens in subgingival plaque samples and has a higher frequency of detection.

Aggregatibacter actinomycetemcomitans↗
PubMed2002

The identification of the transcriptional regulator CRP in Aeromonas hydrophila JMP636 and its involvement in amylase production and the 'acidic toxicity' effect.

AIMS: The physiological examination of amylase production by Aeromonas hydrophila JMP636 and identification of the mechanism of regulation. METHODS AND RESULTS: Aeromonas hydrophila JMP636 was grown with single, then dual carbon sources; the growth cycle was followed and amylase activity throughout was monitored. The levels of cAMP, a known secondary messenger for the regulatory gene crp, were also examined. Amylase activity was regulated by catabolite repression. Physiological studies revealed that JMP636 exhibited both diauxic growth, with two carbon sources, and the 'acid toxicity' effect on glucose. The crp gene was cloned, expressed and inactivated from the JMP636 chromosome. Catabolite repression of amylase production and the 'acid toxicity' effect both require crp and were linked to cAMP levels. CONCLUSIONS: Regulation of amylase production was predicted to follow the model CRP-mediated cAMP-dependent Escherichia coli catabolite regulation system. SIGNIFICANCE AND IMPACT OF THE STUDY: This work provides an understanding of the physiology of the opportunistic pathogen Aer. hydrophila through identification of the mechanism of catabolite repression of amylase production and the existence of crp within this cell. It also provides a broader knowledge of global gene regulation and suggests regulatory mechanisms of other Aer. hydrophila gene/s.

Aeromonas hydrophila↗
PubMed1999

Ticks feeding on humans: a review of records on human-biting Ixodoidea with special reference to pathogen transmission.

In this article, literature records of argasid and ixodid ticks feeding on humans worldwide are provided in view of increased awareness of risks associated with tick bites. Ticks can cause paralyses, toxicoses, allergic reactions and are vectors of a broad range of viral, rickettsial, bacterial and protozoan pathogens. Approximately 12 argasid species (Argas and Ornithodos) are frequently found attached to humans who intrude into tick-infested caves and burrows. Over 20 ixodid tick species are often found on humans exposed to infested vegetation: four of these are Amblyomma species, 7 Dermacentor spp., 3 Haemaphysalis spp., 2 Hyalomma spp. and 6 Ixodes species. Personal protection methods, such as repellents and acaricide-impregnated clothing are advised to minimize contact with infected ticks. Acaricidal control of ixodid ticks is impractical because of their wide distribution in forested areas, but houses infested with soft ticks can be sprayed with acaricidal formulations. Attached ticks should be removed without delay. The best way is to grasp the tick as close to the skin as possible with fine tweezers and pull firmly and steadily without twisting. Finally, despite the fact that most people who are bitten destroy the offending tick in disgust, it is recommended that they preserve specimens in ethanol for taxonomic identification and detection of pathogens by molecular methods.

Animals↗