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At least 811 records · Page 45Linked to original sources
PubMed2006

[Epidemiology of nosocomial bacterial infections in a neonatal and pediatric Tunisian intensive care unit].

OBJECTIVE: The authors had for aim to describe the epidemiology of nosocomial bacterial infections in the neonatal and pediatric intensive care unit of the Tunis children's hospital. DESIGN: A prospective surveillance study was made from January 2004 to December 2004. All patients remaining in the intensive care unit for more than 48 h were included. CDC criteria were applied for the diagnosis of nosocomial infections. RESULTS: 340 patients including 249 (73%) neonates were included. 22 patients presented with 22 nosocomial bacterial infections. The incidence and the density incidence rates of nosocomial bacterial infections were 6.5% and 7.8 per 1,000 patient-days, respectively. Two types of infection were found: bloodstream infections (68.2%) and pneumonias (22.7%). Bloodstream infections had an incidence and a density incidence rate of 4.4% and 15.3 per 1,000 catheter-days, respectively. Pneumonia had an incidence and a density incidence rate of 2% and 4.4 per 1,000 mechanical ventilation-days, respectively. The most frequently isolated pathogens were Gram-negative bacteria (68%) with Klebsiella pneumoniae isolates accounting for 22.7%. The most common isolate in bloodstream infections was K. Pneumoniae (26.7%), which was multiple drug-resistant in 85% of the cases, followed by Staphylococcus aureus (20%). Pseudomonas aeruginosa was the most common isolate in pneumonia (28.6%). Associated factors of nosocomial infection were invasive devices and colonization with multiple drug-resistant Gram-negative bacteria. CONCLUSIONS: The major type of nosocomial bacterial infections in our unit was bloodstream infection and the majority of infections resulted from Gram-negative bacteria. Factors associated with nosocomial bacterial infections were identified in our unit.

Adolescent↗
PubMedDate not supplied

Incidence of bloodstream infections in a speciality hospital in Kuwait: 8-year experience.

OBJECTIVES: To determine the frequency of isolation and antibiotic-susceptibility patterns of clinically significant bacterial pathogens isolated from blood. MATERIALS AND METHODS: The study was conducted over a period of 8 years (1995-2002) at Infectious Diseases Hospital (IDH), Kuwait. Demographic and clinical data were obtained from medical records. 18,535 blood cultures were analyzed. Disk diffusion method was used to perform antibiotic-susceptibility testing. Minimum inhibitory concentrations of 9 antimicrobials were determined using E-test. Double disk (potentiation) test and E-test ESBL strips were used to detect the production of extended-spectrum beta-lactamases (ESBLs). RESULTS: Salmonella spp. and Brucella spp. were predominant blood isolates, and represented 60.6 and 30.0% of all clinically significant episodes of bloodstream infections, respectively. Among the Salmonella, Salmonella enterica serotypes typhi and paratyphi A were most frequently isolated. The percentage of multidrug resistance (MDR) among them varied from 22 to 51%. A high percentage (40%) of MDR S. enterica serotypes typhi and paratyphi A also showed reduced susceptibility to ceftriaxone and ciprofloxacin. CONCLUSION: During the study period, Salmonella spp. and Brucella spp. were predominant blood isolates. MDR S. enterica serotypes typhi and paratyphi A, with reduced susceptibility to ceftriaxone and ciprofloxacin, are among the most frequent causes of bloodstream infections in IDH, suggesting the need to monitor their susceptibility.

Adolescent↗
PubMed1997

Pathobiology of H5N2 Mexican avian influenza virus infections of chickens.

To determine the association between specific structural changes in the hemagglutinin gene and pathogenicity of avian influenza viruses (AIVs), groups of 4-week-old White Plymouth Rock chickens were inoculated intravenously or intranasally with AIVs of varying pathogenicities isolated from chickens in central Mexico during 1994-1995. Mildly pathogenic (MP) viruses had a common hemagglutinin-connecting peptide sequence of Pro-Gln-Arg-Glu-Thr-Arg decreases Gly and had restricted capability for replication and production of lesions in tissues. The principle targets for virus replication or lesion production were the lungs, lymphoid organs, and visceral organs containing epithelial cells, such as kidney and pancreas. Death was associated with respiratory and/or renal failure. By contrast, highly pathogenic (HP) AIVs had one substitution and the addition of two basic amino acids in the hemagglutinin connecting peptide, for a sequence of Pro-Gln-Arg-Lys-Arg-Lys-Thr-Arg decreases Gly. The HP AIVs were pantropic in virus replication and lesion production ability. However, the most severe histologic lesions were produced in the brain, heart, adrenal glands, and pancreas, and failure of multiple critical organs was responsible for disease pathogenesis and death. No differences in lesion distribution patterns or in sites of AIV replication were evident to explain the variation in mortality rates for different HP AIVs, but HP AIVs that produced the highest mortality rates had more severe necrosis in heart and pancreas. The ability of individual HP AIVs to produce low or high mortality rates could not be explained by changes in sequence of the hemagglutinin-connecting peptide alone, but probably required the addition of other undetermined genomic changes.

Adrenal Glands↗
PubMed1976

[Tobramycin sensitivity of bacteria from the Klebsiella-Enterobacter group (author's transl)].

In 300 strains of the Klebsiella-Enterobacter group which were isolated from pathological material from the Bonn University Hospitals in early 1975, the sensitivity to tobramycin was investigated comparatively in a serial dilution test and agar diffusion test. 80% of the strains were seen to be classifiable as sensitive and further 3% as moderately sensitive. The rate to resistance corresponds to that of gentamycin. No difference in resistance behaviour was ascertained in the two bacterial species investigated. However, strains isolated from the urogenital tract are significantly more resistant than pathogens isolated from the respiratory tract.

Anti-Bacterial Agents↗
PubMed1996

Microbial pathogenicity factors as parts of global regulatory networks. (A short review).

Pathogenic bacteria differ from non-pathogenic isolates by the expression of so-called virulence or pathogenicity factors, including adherence molecules, toxins, capsules and others. The majority of the genes encoding pathogenicity factors are not expressed constitutively, but rather undergo environmental regulation or random regulatory events. In enterobacteria, such virulence associated genes are often corregulated with determinants influencing metabolic properties. By analyzing the structure and regulation of genes which are essential for the urovirulence of pathogenic Escherichia coli, we were able to show that genes coding for alfa haemolysin, cytotoxic necrotizing factor I and P fimbriae are located on large instable DNA regions, termed "pathogenicity islands". These islands also comprise regulatory genes which are able to activate adherence specific genes that are not part of those islands. In addition, pathogenicity islands are associated with tRNA loci. One of these tRNA genes, which codes for a minor leucin tRNA and is therefore termed leuX, acts as a global regulator. It influences the expression of various genes of pathogenic E. coli, including adherence specific loci, enterobactin genes, flagella specific gene clusters and determinants involved in serum resistance.

Antigenic Variation↗
PubMedDate not supplied

Phenotypic and plasmid pattern analysis of Staphylococcus epidermidis in bacterial keratitis.

BACKGROUND: Staphylococcus epidermidis, a commensal of the conjunctival sac has been incriminated as the commonest etiological agent of bacterial keratitis. However, the pathogenic potential of this commensal organism is not clearly known. AIM: To determine any phenotypic, molecular markers of S. epidermidis pathogenicity in bacterial keratitis. MATERIALS AND METHODS: A total of 382 corneal ulcer isolates of S. epidermidis and 87 S. epidermidis isolates from healthy eyes (controls) were studied. Speciation, biotyping and antibiotic sensitivity testing were performed by conventional methods. Tube slime and adherence tests were carried out by recommended techniques. Plasmid analysis was conducted by a standard protocol. STATISTICAL ANALYSIS: Chi-square test was employed for calculations. RESULTS: Out of 382 corneal ulcer isolates (Pathogens) 284 (74.3%) belonged to biotypes I and II. Slime was detected in 164 (42.9%) of 382 pathogens vs. 21 (24.1%) of 87 controls (P<0.001). Sixty-five (39.6%) of 164 slime positive isolates were multidrug-resistant as compared to only 49 (22.4%) of 218 slime negative isolates (P<0.001). A significantly higher number i.e, 73.1% (120/164) of slime-producers possessed a 21 Kb plasmid in contrast to only 53.2% (116/218) of nonslime-producers (P<0.001). Presence of this plasmid had a statistical correlation of low significance with multidrug resistance (P=0.04). One hundred and seventy-two (45.0%) of 382 pathogens and 24 (27.6%) of the 87 controls were adherent to artificial surfaces (P=0.003) and the majority of the adherent organisms (99/172, 57.6%) were slime producers (P<0.001). CONCLUSIONS: Slime was associated with multidrug resistance in corneal ulcer isolates of S. epidermidis. The 21 Kb plasmid could determine virulence as it was responsible for slime production and adherence.

Corneal Ulcer↗
PubMed1978

Characterization of an apparently nononcogenic Marek's disease virus.

A new isolate of Marek's disease virus (MDV) was described. This virus, SB, and a clone, SB-1, differed from pathogenic isolates in in vitro growth characteristics as described for other apathogenic isolates. Serologically, as with other apathogenic isolates, SB could be distinguished from pathogenic MDV and the avirulent turkey herpesvirus. SB failed to induce lesions characteristic of Marek's disease (MD) during a 6- to 11-week experimental period. Also, SB was nononcogenic in immunosuppressed chickens or in chickens inoculated with this virus in ovo. However, under those conditions, SB caused a cytolytic infection. The term "nononcogenic" rather than "apopathogenic" was therefore proposed to classify this and similar isolates. SB-1 protected chickens against challenge with either virulent MDV or the non-virus-producing MD tumor transplant, JMV. Possible mechanisms of protection are discussed.

Animals↗
PubMed2004

Bacteria in exacerbations of chronic obstructive pulmonary disease: phenomenon or epiphenomenon?

Our understanding of the pathogenesis and consequences of acute exacerbations of chronic obstructive pulmonary disease (COPD) has increased considerably in the past decade. Several new lines of evidence support bacterial causation of approximately half of the exacerbations in COPD. Acquisition of new strains of bacterial pathogens in patients with COPD is associated with a substantial increase in risk of exacerbation. Bacterial pathogens are isolated in significant concentrations from bronchoscopic samples obtained during acute exacerbation. Neutrophilic airway inflammation is associated with isolation of bacterial pathogens from sputum. A specific immune response to the infecting strains of bacterial pathogens isolated from sputum during exacerbations has been demonstrated. Future work should strive to understand better the host-pathogen interaction that leads to an exacerbation and to develop novel therapeutic and preventive measures.

Acute Disease↗
PubMed1978

Effect of Fusarium isolates and their filtrates on respiratory rate and chemical analysis of squash plants.

The highly pathogenic isolate stimulated the emergence of the squash seedlings first, caused, however, the highest death rate of the seedlings finally. Fusarium isolates and their culture filtrates inhibited the respiratory rate of squash plants significantly. However, F. oxysporum isolates inhibited respiration more than F. solani isolates. Seasonal changes of respiration decline show that the respiratory rate decreased with plant growth in the case of infested soil and of plants injected with culture filtrates. However, spraying Fusarium culture filtrates on the foliage gave opposite results when the plants grew older. Fusarium solani isolates decreased nitrogen content of squash stems and leaves, while F. oxysporum isolates gave reverse results. Injecting Fusarium culture filtrate into the plant decreased nitrogen content of both stems and leaves, while spraying the foliage with the filtrates increased nitrogen content more than that of the control. Phosphorus content of the stems of squash plants, sown in infested soil, was less than in the control when the plants were treated with F. solani and higher when they were treated with F. oxysporum isolates. On the other hand, the phosphorus content of squash leaves was higher than in the control. In the case of injected plants, however, the phosphorus content in stems and leaves was equal to that of the control or less, and with sprayed plants it was higher than in the control. Infesting the soil with Fusarium isolates and spraying the foliage with their culture filtrates increased potassium content of squash stems and leaves, while injecting the filtrates into the plants decreased potassium content of both stems and leaves.

Fusarium↗
PubMed1989

[Gram-negative bacteria isolated from wound infections and their susceptibility to various antibiotics].

In this study gram negative pathogens isolated from wound infections and antibiotic susceptibilities of these bacteria were evaluated by using Sceptor (BBLR) microdilution system. According to the our results, it was observed that Enterobacter sp. were found to be major causative agent with the ratio of 22.67%. The isolated gram negative bacteria have been found to be highly resistant to the most of the antibiotics except amikacin.

Anti-Bacterial Agents↗
PubMed1989

[Detection of gram-positive bacteria isolated from wound infections and their susceptibility to various antibiotics].

In this study gram positive pathogens isolated from wound infections and antibiotic susceptibilities of these bacteria were evaluated by using sceptor (BBL) microdilution system. According to our experimental results, it was observed that the staphylococci found to be major causative agent with the ratio of 72%. The sensitivity of gram positive bacteria have been found aminoglycosides 88%, trimethoprim/sulphamethoxazole 67%. The sensitivity of these bacteria to the other antibiotics have been found 13-59%.

Aminoglycosides↗
PubMed1994

Comparative efficacy and safety of cefprozil and amoxycillin/clavulanate in the treatment of acute otitis media in children.

Cefprozil is a new oral cephalosporin with activity against the most common pathogens isolated in acute otitis media. This randomized study enrolled 361 patients (mean age 29 months). Physical examination and culture via tympanocentesis were required less than 48 h before therapy. One hundred and ninety-one patients were evaluable for clinical efficacy; 99 received cefprozil (20 mg/kg/day bd) and 92 received amoxycillin/clavulanate (13.3 mg/kg/day tid). Duration of treatment was 7-9 days for 81 patients, 10 days for 105 patients and 11-16 days for five patients. The treatment groups were comparable with respect to demographics, severity of infection and number of previous episodes. Clinical evaluations of efficacy were based on physical examination including otoscopy within a 14 day period after therapy. Satisfactory clinical responses were achieved in 84% of cefprozil-treated patients and 87% of amoxycillin/clavulanate-treated patients. Pathogens most commonly isolated included Haemophilus influenzae (33%) and Streptococcus pneumoniae (22%). All 361 patients were evaluable for safety. Adverse clinical events were reported in 13% (24) of cefprozil-treated patients and 20% (36) of amoxycillin/clavulanate-treated patients. Cefprozil, administered twice a day, is comparable to a regimen of amoxycillin/clavulanate three times a day in the treatment of acute otitis media in children.

Acute Disease↗
PubMed2003

Bacteremia in adults admitted to the Department of Medicine of Bangui Community Hospital (Central African Republic).

To determine which pathogens are responsible for bloodstream infections in Bangui and to which antibiotics these pathogens are resistant, we conducted a prospective study of the bacteria isolated from the blood of febrile patients hospitalized in the department of medicine of the Bangui Community Hospital after the failure of antimalarial treatment. One hundred and thirty-one patients were included in this study. Bacteria were identified in 49 blood cultures (37.4%). Eleven different species were identified. Bacteremia was more frequent in HIV-positive patients than in HIV-negative patients. Salmonella typhimurium, Mycobacterium tuberculosis and Streptococcus pneumoniae were the most frequently isolated pathogens. Eighty percent of enterobacteria were resistant to amoxicillin and 85% to trimethoprim-sulfamethoxazole. Ciprofloxacin and ceftriaxone were the most efficient antibiotics for the enterobacteria, but chloramphenicol and gentamicin were efficient in most cases. Some strains of S. pneumoniae displayed reduced susceptibility to penicillin G, but all strains were susceptible to erythromycin.

Adolescent↗
PubMed2003

Occurrence of sessile Pseudomonas oryzihabitans from a karstified chalk aquifer.

Pseudomonas oryzihabitans is an uncommon pathogen that may cause opportunistic infections. Although it has been previously isolated from the environment, the source of human infection has not been well documented. In this study, we describe the presence of P. oryzihabitans adhering on suspended particulate matters recovered from karst groundwaters. The isolated pathogen was capable of forming biofilms on silicon supports and clay beads. Adherent P. oryzihabitans cells displayed a high resistance to chlorine as compared with the same organisms cultured in the planktonic mode. These results demonstrate that aquifer biofilms are potential environmental sources for water-born P. oryzihabitans infections and that bacterial attachment might affect drinking water purification.

Aluminum Silicates↗
PubMed1984

Bacteraemia among children in hospital--a four year prospective study.

The incidence of bacteraemia in children (excluding newborn babies) admitted to a general hospital during the period 1978 to 1981 was 3.2 patients per 1000 admissions. Of the total, nosocomial bacteraemia comprised 0.7 patients per 1000 admissions. Analysis of some probable risk factors showed that the chance of acquiring bacteraemia in the first year of life was 6.8 times that for older children, the difference being statistically significant (P less than 0.001). The male to female ratio was 1.7: but this difference was not statistically significant. Overall the case mortality rate was 4.5%. For nosocomial bacteraemia the rate was much higher (14.3%) than that of community acquired bacteraemia (1.9%) with a risk of dying 7.5 times greater (P less than 0.01). Of the pathogens isolated 71.2 per cent were Gram-negative, Escherichia coli being the most common followed by Salmonella typhi. Among the Gram-positive organisms isolated, as well as overall, the pneumococcus was the most common pathogen. Pneumonia and gastroenteritis were the underlying conditions most often found. Since the pneumococcus was the most common pathogen, and in all of our patients originated in the community, physicians who treat in out-patient clinics as well as emergency rooms should be aware of this and look especially for the early symptoms and signs of disease likely to be caused by this organism.

Adolescent↗
PubMed1983

Impact of viral respiratory diseases on infants and young children in a rural and urban area of southern West Virginia.

Acute viral respiratory disease occurring in children residing in the community of Huntington, West Virginia (urban children) or in the hollows surrounding Huntington (rural children) was evaluated from September 1978 through March 1980. Cohorts of ambulatory children residing in each area were studied for the occurrence of mild to moderate respiratory disease. All children admitted to hospitals were evaluated for the occurrence of severe viral respiratory disease. Respiratory secretions were obtained from children for isolation of viruses. Epidemics of illnesses occurred simultaneously in the urban and rural groups of children. Among both the urban and rural ambulatory children, adenoviruses were the most common viruses isolated, and respiratory syncytial virus was the second most common viral pathogen isolated. Among the urban and rural hospitalized children, respiratory syncytial virus was the most common virus isolated. The distribution of the diagnoses, pneumonia, bronchiolitis, or croup, was similar among the urban and rural children who required hospitalization. The risk of hospitalization because of respiratory disease was found to be one in every 20 children during the first four years of life, and the estimated risk of hospitalization because of respiratory syncytial virus infection was one in 30. No differences were detected in the incidence of severe viral respiratory disease among children residing in urban or rural areas in southern West Virginia.

Child, Preschool↗
PubMed1995

Genes Essential for Amber Disease in Grass Grubs Are Located on the Large Plasmid Found in Serratia entomophila and Serratia proteamaculans.

The bacteria Serratia entomophila and S. proteamaculans cause amber disease in the grass grub, Costelytra zealandica (Coleoptera: Scarabaeidae), an important pasture pest in New Zealand. Disease symptoms include rapid cessation of feeding and amber coloration of larvae. A 105-kb plasmid (designated pADAP) has consistently been found only in pathogenic isolates of both species. Investigations into the involvement of pADAP in amber disease have been hindered by the lack of both a selectable marker on the plasmid and a reliable transposon delivery system. Kanamycin-resistant transposon insertions into three cloned HindIII fragments (9.5, 9.6, and 10.6 kb) were isolated and introduced into pADAP by shuttle mutagenesis. Inserts into the 9.5-and 9.6-kb HindIII fragments on pADAP did not alter disease-causing ability. When plasmids with inserts into the 9.6-kb region were conjugated into plasmid-minus, nonpathogenic isolates of S. entomophila and S. proteamaculans, all of them became pathogenic. Transposon insertions into two regions of the 10.6-kb HindIII fragment continued to cause cessation of feeding but failed to produce amber coloration. Further analysis of a mutant from each amber-minus region (pADK-10 and pADK-13) demonstrated that the antifeeding effect was produced only at dosages higher than that of the wild-type strain. Complementation with the wild-type HindIII fragment restored full-blown disease properties for pADK-13, but not for pADK-10.

Journal Article↗
PubMed1997

[Bacteraemia in patients with HIV disease: aetiological spectrum and profile of antimicrobial susceptibility].

A retrospective survey of non-opportunistic bacterial pathogens isolated from blood cultures of patients with HIV disease has been carried out for a 6-year period, and the antibiotic susceptibility of the 748 microorganisms cultured from 682 consecutive patients, has been evaluated. Gram-positive organisms significantly prevailed over gram-negative ones, with Staphylococcus aureus, coagulase-negative staphylococci, Enterococcus faecalis, Xantomonas maltophilia, Salmonella and Pseudomonas sp. as the most common isolates, and Rhodococcus equi, Serratia, Acinetobacter and Alcaligenes sp. as emerging pathogens. Useful suggestions may be obtained for empiric antimicrobial treatment of suspected sepsis in HIV-infected patients, from the evaluation of the antibiotic susceptibility profile of these non-opportunistic bacterial pathogens.

English Abstract↗