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PubMed2004

Two-stage anaerobic digestion process for complete inactivation of enteric bacterial pathogens in human night soil.

Anaerobic digestion offers a good alternative for human waste treatment. However, the fate of enteric bacterial pathogens present in human night soil (HNS) remains a major concern for hygienic safety of the process. A two-stage anaerobic digestion process, consisting of separate acidogenic and methanogenic digesters, was designed and its efficacy in the inactivation of Salmonella typhi was compared to a single-stage digestion process. In a single-stage digestion, complete pathogen inactivation was achieved only in the digesters with high levels of volatile fatty acids (VFA approximately equal to 18,000 mg/l) and acidic pH (approximately equal to 6.0). These digesters, however, showed drastic reduction in methane yield. In the two-stage digestion process, S. typhi was completely inactivated in the acidogenic digester and the methanogenic digester was free from the pathogen even after receiving a daily dose of the pathogen. The process also achieved complete inactivation of other enteric pathogens, viz., Shigella dysenteriae and Vibrio cholerae. The two-stage process was efficient in biogas generation from HNS. Thus, the two-stage process ensures complete hygienic safety in anaerobic digestion of human night soil.

Bacteria, Anaerobic↗
PubMed2004

[The pathogens and their antibiotic sensitivities in hospital-acquired pneumonia cases].

Dynamic precautions in the early diagnosis and treatment of hospital acquired pneumonias are necessary because of their high mortality. In these patients, invasive diagnostic approaches may be needed since clinical and radiological findings and other non-invasive approaches frequently fail to establish the diagnosis. Thirty eight patients were prospectively included in the study. Average age of patients was 45.5 +/- 16.4 years; 31 were males (81.6%) and 7 (18.4%) were females. Pneumonia was detected in 9 (23.7%) cases during the first five days and in 29 (76.3%) cases after the fifth day of admission to the hospital. Bronchoscopic interventions diagnostic purpose were carried out in 25 (65.8%) patients. The culture results were negative in 7 (18.4%) cases. While more than one pathogen was determined on the cultures of 16 (42.1%) patients only one pathogen was isolated in the cultures of 15 (39.4%) cases. The frequently isolated pathogen on cultures was Staphylococci (45.4%). Other pathogens were Enterobacter spp., Pseudomonas spp., Escherichia coli, Serratia and Streptococcus pneumoniae according to their frequency on cultures. High resistance rates to the third generation cephalosporins were determined. Eleven of 17 deaths in 38 pneumonia cases were attributable to pneumonia. As a conclusion, isolation of pathogen and antibiotic resistance should be determined in the cases with hospital acquired pneumonia. Invasive diagnostic interventions were not avoided when necessary. Although pro-BAL and PSB methods were expensive, their use in selected cases may prevent unnecessary antibiotic use and contribute to a decrease in mortality rate.

Anti-Bacterial Agents↗
PubMed2004

[Analysis of the distribution characteristics and drug sensitivity of infection pathogens in hematology department ward].

The objective of this study was to investigate clinical distribution characteristics and drug sensitivity of infection pathogens in hematology department wards of our hospital during recent two years. The isolation and cultivation of pathogens from samples were performed by routine methods. Drug sensitivity tests of bacteria were performed by Kirby-Bauer method. Drug sensitivity tests of fungi were performed by ATBFUNGUS Drug sensitivity strips. The results showed that 102 strains of pathogens were isolated from all detected samples. The composition ratio of Gram-positive bacteria, Gram-negative bacteria and fungi was 42.2%, 34.3%, 3.5%, respectively. 58.8% of pathogens were isolated from samples of malignant hematopathy patients. 27.5% were isolated from samples of the patients with fever of unknown origin (FUO). 51.0% of pathogens were isolated from samples of the patients who suffered from agranulocytosis or leucocytopenia. Isolated fungi were mostly sensitive to anti-fungal drugs. G+ bacteria were most sensitive to vancomycin. G- bacteria were most sensitive to imipenem. Most bacteria were resistant to multiple antibiotics. It is concluded that the infection in hematology department wards was related with many conditions, such as weakened resistance of patients, leucocytopenia or agranulocytosis, tumor loading, etc. The prompt microbiological examination and drug sensitivity tests are important to rationally select antibiotics, reduce infection incidence and mortality rate, and decrease the occurrence of drug resistant strains.

Cross Infection↗
PubMed2004

[Rapid pathogens diagnosis of infected keratitis and endophthalmitis using two steps polymerase chain reaction].

OBJECTIVE: To establish a rapid diagnosis technique of the pathogens of infected keratitis and endophthalmitis. METHODS: Fifty-one corneal scraping, tear and 16 vitreous specimens were obtained from 67 cases of infected keratitis and endophthalmitis. Multiplex polymerase chain reaction (MPCR) was performed to differentiate the genes of bacteria, fungi and HSV using their own universal primers. Special-primers PCR were carried out for MPCR positive specimens to detect the genes of common bacteria and fungi respectively. The results were compared with microbe culture and clinical diagnosis. RESULTS: In 67 clinical samples, 52 (77.6%) were positive at least one kind of pathogen by MPCR (two positive pathogens were 8 cases). SPCR revealed that 7 bacteria (25.0%) out of 28 bacteria positive specimens were Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa. Eight fungi (53.3%)of 15 fungi positive specimens was Candida, Aspergillus, Fusarium. The culture positive rates were 31.3% (21 cases), among them 1 case was found positive for two pathogens. MPCR positive rate was statistically higher than the rate that in culture (chi(2) = 13.50, P < 0.005). The kinds of bacteria and fungi of SPCR positive were as the same as bacteria and fungi of culture positive. Consistency of clinical diagnosis and experimental evidences of infected keratitis was 54.8%. The time for microbe culture needs 72 to 96 hours, but MPCR and SPCR needs 8 hours. CONCLUSION: Two steps PCR is rapid, sensitive method to detect the pathogens of infected keratitis and endophthalmitis.

Adolescent↗
PubMed2004

PathoPlant: a database on plant-pathogen interactions.

Pathogen recognition and signal transduction during plant pathogenesis is essential for the activation of plant defense mechanisms. To facilitate easy access to published data and to permit comparative studies of different pathogen response pathways, a database is indispensable to give a broad overview of the components and reactions so far known. PathoPlant has been developed as a relational database to display relevant components and reactions involved in signal transduction related to plant-pathogen interactions. On the organism level, the tables 'plant', 'pathogen' and 'interaction' are used to describe incompatible interactions between plants and pathogens or diseases. On the molecular level, plant pathogenesis related information is organized in PathoPlant's main tables 'molecule', 'reaction' and 'location'. Signal transduction pathways are modeled as consecutive sequences of known molecules and corresponding reactions. PathoPlant entries are linked to associated internal records as well as to entries in external databases such as SWISS-PROT, GenBank, PubMed, and TRANSFAC. PathoPlant is available as a web-based service at http://www.pathoplant.de.

Computational Biology↗
PubMed2005

[Detection of sexually transmitted pathogens in patients with hematospermia].

BACKGROUND: Although the current literature attributes most cases of hematospermia to an infectious agent, identification of the specific pathogens involved has been limited. OBJECTIVE: To determine the prevalence of different pathogens, in patients presenting with hematospermia to our sexually transmitted disease clinic. PATIENTS AND METHODS: We retrospectively examined the laboratory results of 30 patients who presented to our clinic with hematospermia after other non-infectious pathologies had been excluded by a referring physician. Firstly, void urine samples as well as genitourinary and serum specimens were tested for Herpes simplex, Chlamydia trachomatis and Ureaplasma urealyticum. Standard bacterial cultures were also performed. RESULTS: In 12 of the 18 patients a possible pathogenic cause for the hematospermia was found. Evidence for Herpes simplex virus (Type 2) was found in 5 of the patients (16.6%), for Chlamydia trachomatis in 3 patients (10%) and for Ureaplasma urealyticum in 2 of the patients. Enterococcus fecalis was detected in 2 (6.6%) of the patients and in 1 patient Herpes simplex virus (Type 1) antigen and antibodies were detected. In all cases in which evidence of a pathogen was identified, the appropriate antimicrobial agent was administered, with recurrence in two patients only. CONCLUSIONS: Recent advances in microbiologic diagnostic techniques have facilitated the detection of pathogens in patients with hematospermia, thereby enhancing the efficacy of treatment.

Chlamydia trachomatis↗
PubMed2005

[Antigenome technology: rapid and comprehensive identification and validation of antigens as putative components in vaccines against bacterial pathogens].

The resolution of complete genome sequences of many pathogens has dramatically expanded our perspectives in developing novel vaccines by increasing both the speed and scale of target identification. Genomics-based technologies with their significant advantages can be applied to most pathogens and have exploited genome sequence information in alliance with adjunct technologies, including bioinformatics, expression analyses (microarrays, in vivo expression technologies), random mutagenesis or protein/peptide based selection methods (proteomics and immunoselection using expression libraries). A novel approach that combines the advantages of full genome coverage and serological antigen identification has been developed in the laboratory of the authors for the identification of protein antigens from bacterial pathogens. This technology has been applied to several bacterial pathogens and, as a result, defined the most relevant antigenic proteins that are targeted by the human immune system, including their antibody binding sites (epitopes). This catalogue of antigens is termed the antigenome and the novel technology offers an integrated approach for antigen validation in order to select the most promising candidates for the development of subunit vaccines against the targeted bacterial diseases. Using the antigenome technology, novel protective antigens had been discovered from several important human pathogens.

Antigens, Bacterial↗
PubMed2005

Detection of pathogens causing genital ulcer disease by multiplex polymerase chain reaction.

OBJECTIVE: To establish a multiplex polymerase chain reaction (M-PCR) assay for simultaneous detection of pathogens causing genital ulcer disease (GUD). METHODS: Based on the gene-specific region of the following pathogens: Chlamydia trachomatis omp1/ompb, herpes simplex virus (HSV) DNA polymerase, Treponema pallidum tpp47, Haemophilus ducreyi 16s rRNA, four sets of primers were designed and an M-PCR assay was developed to detect four pathogens in one test. The assay was evaluated with diagnostic result of golden standard for each pathogen. RESULTS: Of the 51 clinical samples, M-PCR showed slightly higher positive rate (47.1%) of HSV than cell culture (23.6%). Meanwhile, the positive rate of T. pallidum detected by M-PCR and dark-field microscopy was 19.6% (10/51) and 15.7% (8/51), respectively. Only one sample was positive for H. ducreyi and no sample was positive for C. trachomatis detected by both M-PCR assay and culture. CONCLUSION: This primary study indicated that M-PCR assay can simultaneously and rapidly detect the four etiologic pathogens causing GUD.

Chlamydia trachomatis↗
PubMed2006

Surveillance of antimicrobial resistance of invasive pathogens: the Estonian experience.

The aim of the present study was to evaluate the needs for surveillance of invasive Gram-negative pathogens in Estonia. The antimicrobial susceptibility data of invasive isolates of Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella spp, Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae and enterococci were collected in accordance with EARSS (European Antimicrobial Resistance Surveillance System) protocols. Despite the higher rate of Gram positive pathogens, their resistance to antimicrobials was low in contrast to the elevated resistance established for Gram negative pathogens. The higher resistance to antimicrobials was particularly associated with A. baumannii and P. aeruginosa. Also, the proportion of extended spectrum betalactamase (ESBL)-producing strains was 23% among Klebsiella spp. and 3.6% among E. coli. The inclusion of invasive Gram negative pathogens in antimicrobial resistance surveillance provides useful information concerning local pathogen susceptibility, as well as for the empirical treatment of suspected infections.

Drug Resistance, Microbial↗
PubMed2006

[Bacterial pathogens and resistance patterns in community acquired pediatric urinary tract infection: experience of 152 cases].

OBJECTIVE: This study investigated the pathogen distribution and resistance patterns in childhood urinary tract infection in order to provide references for optimal use of antibiotics in the treatment of this disorder. METHODS: The clinical data of 152 children with community acquired urinary tract infection (urinary culture positive) between December 2001 and December 2004 were studied retrospectively. The bacterial pathogens of urinary tract infection and antimicrobial resistance were analyzed. RESULTS: Gram-negative bacilli was predominant pathogenic bacteria, accounting for 79.0% of the cases, and Escherichia coli (E. coli) was most commonly found (56.2%). Gram-positive cocci accounted for 18.4%, including 15.1% of Enterococcus faecalis. Fungi was rarely seen, accounting for only 2.6%. E. coli had a resistance rate of more than 50% to ampicillin, amoxicillin/clavulate, co-trimoxazole, cefradine, and fosomycin, but a very low resistance rate (< 4%) to 3rd generation cefalosporin, nitrofurantoi, azactom and amikacin. Enterococcus faecalis had a low resistance rate (< 20%) to ampicillin, vancomycin, penicillin, and nitrofurantoin. CONCLUSIONS: E. coli is the major pathogen in community acquired pediatric urinary tract infection, and Enterococcus has been become another important pathogen. Selection of antibiotics for the treatment of this disorder should base on drug-sensitive test results.

Adolescent↗
PubMed2005

Induction of resistance to the pathogenic agent Botrytis cinerea in the cultivation of the tomato by means of the application of the protein "Harpin"(Messenger).

Harpin(Ea), an active component in Messenger, was originally isolated from the bacterial plant pathogen Erwinia amylovora based on its ability to elicit a hypersensitive response (HR). This bacterial pathogen causes "fire blight", a disease in apples and other members of the Rosaceae. Harpin(Ea) also induces resistance in a variety of plants against a wide array of pathogens. The objective of this investigation was to determine indications of resistance induction to Botrytis cinerea in the plants treated with the formulated Harpin(Ea) protein. This pathogenic agent is responsible for important economic losses in the cultivation of both greenhouse and field grown tomatoes. Plants with and without Messenger applications were inoculated with Botrytis cinerea in the same way. In addition, some plants with and without Messenger applications were not inoculated. Inoculated plants were symptomatologically checked for local and systemic symptoms. Evaluations of the number of tomatoes produced and their growth were also carried out. The results obtained demonstrate that there were active defence systems in the plant, producing a reduction in the damage caused by the pathogenic agent Botrytis cinerea. A greater growth also took place in the fruit obtained. These results show that the formulated Harpin(Ea) protein could reduce the use of chemical agents and be a new tool to serve as the basis for an Integrated Pest Management system.

Bacterial Outer Membrane Proteins↗
PubMed2006

Microbial pathogens of adult community-acquired pneumonia in Southern Estonia.

Prospective analysis of the etiology of community-acquired pneumonia in 209 inpatients (mean age 56.2+/-11.2 years) was performed at the Lung Hospital of Tartu University, Estonia. Majority of the patients (87.6%) had at least one significant modifying or risk factor and 30.6% had severe community-acquired pneumonia. Streptococcus pneumoniae, beta-hemolytic streptococci, Klebsiella pneumoniae, and Moraxella catarrhalis were the most frequent pathogens (22.0, 12.2, 11.4, and 10.2%, respectively). Combined etiology was detected in 17.2%. Gram-negative pathogens prevailed over gram-positives and were significantly more frequent in patients aged > or =60 years (p=0.002) as in those with underlying diseases (p=0.01). An age of > or =60 years and previous antibacterial therapy were significant risk factors for Klebsiella pneumoniae as a pathogen (p=0.005 and p=0.002, respectively). Susceptibility of Streptococcus pneumoniae to penicillin, erythromycin, and doxycycline was 79.5, 90.2, and 100%, respectively, whereas all penicillin-resistant isolates were cefuroxime- and ceftriaxone-susceptible. Klebsiella pneumoniae was 100, 88.5, 84.2, and 81.8% susceptible to ceftazidime, gentamicin, ampicillin-sulbactam, and ciprofloxacin, and Moraxella catarrhalis was 100, 100, 100, 93.8, and 93.3% susceptible to ampicillin-sulbactam, cephalexin, ceftriaxone, ciprofloxacin, and erythromycin, respectively. In conclusion, Streptococcus pneumoniae, Moraxella catarrhalis, and Klebsiella pneumoniae were the major pathogens of community-acquired pneumonia in Southern Estonia. Although gram-negatives were more prevalent, the major pathogens were favorably susceptible without a noticeable cross-resistance. Nevertheless, improved surveillance studies are needed because of a pressure for the rise in antibiotic resistance in the society.

Adolescent↗
PubMed2006

[DNA microarrays and their application in detecting and identifying intestinal pathogens].

DNA microarrays offer many advantages of high throughout, automation, rapid detection, and so on. Therefore, this technology had been used in many fields such as molecular epidemiology of bacteria, microbial gene identification, disease mechanism, gene mutation, gene expression identification, DNA sequencing and medicine screening etc. The assays for identifying pathogens using DNA microarrays reported aboard recently are introduced. The application of DNA microarrays in detecting and identifying intestinal pathogens mainly includes three aspects: the identification of toxin and characteristic genes of pathogens, the identification of bacterial DNA or RNA directly, the simultaneous detection of a large number of intestinal pathogens with the target - gene of ribosomal RNA. Because of its high efficiency, DNA microarrays is superior to other biological method. Obviously DNA microarrays technology may be useful in identifying intestinal pathogens and have a wide prospect.

Animals↗
PubMed2005

Induction of resistance in host against the infection of leaf blight pathogen (Alternaria palandui) in onion (Allium cepa var aggregatum).

The Pseudomonas fluorescens isolate Pfl was found to inhibit the growth of pathogen Alternaria palandui, in vitro. In the present study, foliar application of a talc-based formulation of Pfl significantly reduced the incidence of leaf blight of onion, caused by A. palandui. Induction of defense-related proteins viz., chitinase, beta-1,3 glucanase, peroxidase (PO) and polyphenol oxidase (PPO) by application of Pfl, was studied against A. palandui infection in resistant (IHR 56) and susceptible (MDUI) onion cultivars. Chitinase in both cultivars, with or without challenge-inoculation of A. palandui revealed changes in the isoform pattern. The Native-PAGE of PO showed induction of PO2 isoform in both the cultivars, in response to inoculation of pathogen. Isoform analysis of PPO also exhibited induction in the Pfl-treated plants challenged with pathogen. Similarly, the activity of beta-1,3-glucanase was greatly induced in Pfl-treated plants, challenged with pathogen as compared to controls. Thus, the P. fluorescens-treated plants showed significant increase in the levels of the defense enzymes, in comparison to the plants challenged with the pathogen.

Catechol Oxidase↗
PubMed2006

[Treatment and course of community-acquired pneumonia caused by atypical pathogens].

OBJECTIVE: To study the course of disease and outcomes in a group of patients with community-acquired pneumonia caused by atypical pathogens (Mycoplasma pneumoniae, Legionella species ,Coxiella burnetii, and Chlamydophila pneumoniae) according to the empiric treatment received. PATIENTS AND METHODS: Of a total of 390 patients admitted to our hospital with pneumonia between January 1996 and February 2001, the causative microorganism was an atypical pathogen in 89 cases. Patients were divided retrospectively into 2 groups according to the empiric treatment they received: group A, who had received an antibiotic regime (quinolones or macrolides) that provided coverage for atypical pathogens; and group B, who had received treatment that did not provide such coverage. Clinical course was assessed in terms of the differences between the 2 groups in length of hospital stay, radiographic resolution, readmission at 30 days after discharge, and mortality. RESULTS: A total of 89 patients with pneumonia caused by atypical pathogens (39 in group A and 50 in group B) were studied. No significant between-group differences in the variables were found. CONCLUSIONS: In this group of patients hospitalized for community-acquired pneumonia, antibiotic regimens providing coverage for atypical pathogens did not improve either clinical or radiographic evolution.

Adult↗
PubMed1991

Homologous cysteine proteinases of pathogenic and nonpathogenic Entamoeba histolytica. Differences in structure and expression.

A cDNA clone derived from the gene encoding a cysteine proteinase of pathogenic Entamoeba histolytica was isolated using an antiserum to the purified enzyme. This clone was used to identify the homologous clone in a cDNA library from nonpathogenic E. histolytica. Sequence analysis and comparison of the predicted amino acid sequences revealed a sequence divergence of 16%. Southern blot analyses indicated that (i) pathogenic isolates may contain more genes coding for these or related enzymes than nonpathogenic isolates, (ii) the structure and organization of these genes are conserved within each group of amoebae, and (iii) none of the genes is found in both pathogenic and nonpathogenic E. histolytica, underlining the notion that the two groups are genetically distinct. Northern blot analyses suggested that the cysteine proteinase is expressed by pathogenic isolates in substantially higher amounts than by nonpathogenic isolates. Overexpression of this enzyme may be an important factor in the pathogenicity of E. histolytica.

Amino Acid Sequence↗
PubMed2006

Antimicrobial effect of acidified nitrate and nitrite on six common oral pathogens in vitro.

BACKGROUND: Salivary nitrate is positively correlated with plasma nitrate and its level is 9 times the plasma level after nitrate loading. Nitrate in saliva is known to be reduced to nitrite by oral bacteria. Nitrate and nitrite levels in saliva are 3 - 5 times those in serum in physiological conditions respectively in our previous study. The biological functions of high salivary nitrate and nitrite are still not well understood. The aim of this in vitro study was to investigate the antimicrobial effects of nitrate and nitrite on main oral pathogens under acidic conditions. METHODS: Six common oral pathogens including Streptococcus mutans NCTC 10449, Lactobacillus acidophilus ATCC 4646, Porphyromonas gingivalis ATCC 33277, Capnocytophaga gingivalis ATCC 33624, Fusobacterium nucleatum ATCC 10953, and Candida albicans ATCC 10231 were cultured in liquid medium. Sodium nitrate or sodium nitrite was added to the medium to final concentrations of 0, 0.5, 1, 2, and 10 mmol/L. All of the microorganisms were incubated for 24 to 48 hours. The optical densities (OD) of cell suspensions were determined and the cultures were transferred to solid nutrient broth medium to observe the minimum inhibitory concentration and minimum bactericidal/fungicidal concentration for the six tested pathogens. RESULTS: Nitrite at concentrations of 0.5 to 10 mmol/L had an inhibitory effect on all tested organisms at low pH values. The antimicrobial effect of nitrite increased with the acidity of the medium. Streptococcus mutans NCTC 10449 was highly sensitive to nitrite at low pH values. Lactobacillus acidophilus ATCC 4646 and Candida albicans ATCC 10231 were relatively resistant to acidified nitrite. Nitrate at the given concentrations and under acidic conditions had no inhibitory effect on the growth of any of the tested pathogens. CONCLUSION: Nitrite, at a concentration equal to that in human saliva, is both cytocidal and cytostatic to six principal oral pathogens in vitro, whereas nitrate at a similar concentration has no antimicrobial effect on these organisms.

Anti-Infective Agents↗
PubMed2006

[The drug resistance of pathogenic bacteria of nosocomial infections in surgical intensive care unit].

OBJECTIVE: To investigate the drug resistance of pathogenic bacteria of nosocomial infections in the surgical intensive care unit. METHODS: The drug resistance of pathogenic bacteria of nosocomial infections in the SICU in our hospital from January 2001 to December 2004 were analyzed. RESULTS: The average nosocomial infections rate was 11.3%. The major sites of nosocomial infections were respiratory tract (30.9%), abdominal cavity (29.0%), bloodstream (9.7%) and biliary ducts (7.2%). The most common pathogens were pseudomonas aeruginosa (11.6%), methicillin-resistant coagulase negative staphylococci (11.1%) and candida albicans (9.7%). ESBLs-producing strains accounted for 66.2% and 58.5% of escherichia coli and klebsiella spp. respectively. Methicillin-resistant staphylococcus aureus accounted for 94.7% and methicillin-resistant coagulase negative staphylococci accounted for 88.2% in staphylococcus aureus and coagulase negative staphylococci. Carbapenems were the most powerful antibiotics against enterobacteriaceae. The non-fermenters were high resistant to antimicrobial agents. Vancomycin was the most potent antimicrobial against gram positive cocci. Amphotericin B was the most active antibiotic against fungi. CONCLUSIONS: Most strains of pathogens were antibiotic resistant in SICU. The main pathogenic bacteria of each infection site were different. So it is essential to establish nosocomial infections surveillance system in order to prevent, control and treat nosocomial infections effectively.

Bacterial Infections↗