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At least 199 records · Page 11Linked to original sources
PubMed1998

Comparison between homologies of E2/NS1 gene from genotype III Chinese isolates of hepatitis C virus and that from reported isolates.

OBJECTIVES: To sequence E2/NS1 gene from genotype III Chinese isolates of hepatitis C virus (HCV) and analyze homology corresponding to the region of the reported isolates. METHODS: E2/NS1 gene derived from genotype III Chinese isolates of HCV was amplified by reverse transcripase-polymerase chain reaction (RT-PCR) and cloned into vector pcDNA3. Dideoxy chain termination methods were used to sequence E2/NS1 gene. RESULTS: E2/NS1 gene derived from genotype III Chinese isolates of HCV was cloned for the first time and named HC-W14. Identity of HC-W14 in nucleotide and putative amino acid to those of genotype III Japanese isolates of HCV were 88.37% and 89.29% respectively. Homology to that of non-type III isolates was relatively low. CONCLUSIONS: High variation existed in E2/NS1 region between genotype III and II Chinese isolates of hepatitis C virus. The variability of E2/NS1 gene should be taken into account in the development of vaccine against HCV in China.

Amino Acid Sequence↗
PubMed2002

Virulence of South African isolates of Haemophilus paragallinarum. Part 1: NAD-dependent field isolates.

The virulence of four South African field isolates of NAD-dependent Haemophilus paragallinarum, representing the four serovars known to occur in that country, was investigated. During this study an alternative challenge model for infectious coryza was used, in which the infectivity as well the virulence of different isolates could be evaluated. The challenge model consisted of the direct challenge, via intrasinus injection of one chicken in a row of interconnected layer cages, containing 10 chickens, which are subsequently infected by natural routes. A scoring system of the clinical signs was established in which a score is given to the ability of the isolate to produce clinical signs in the challenge birds. The mean daily disease score for the flock can be calculated and plotted on a graph to give a graphic representation of the disease profile. A mean disease score, calculated over a 20-day examination period can be calculated. Isolates can then be compared to each other, either graphically or by a comparison of the mean disease scores. It has been demonstrated using this scoring system that the South African serogroup C isolates appear to be more virulent than the South African serogroup A or B isolates. It was further established that the serovar C-3 isolate appeared to be the most virulent.

Animals↗
PubMed2002

Virulence of South African isolates of Haemophilus paragallinarum. Part 2: naturally occurring NAD-independent field isolates.

Naturally occurring NAD-independent variants of Haemophilus paragallinarum, which have been isolates from poultry showing clinical signs of infectious coryza, were used to determine their virulence using a newly developed challenge model for infectious coryza. It was established that the NAD-independent isolates belonging to a particular serogroup, were less virulent when compared to the virulence of the NAD-dependent isolates from the same serogroup. It was shown that the virulence of the NAD-independent isolates belonging to serogroup C and serogroup A were very similar to each other. This differs to the results obtained with NAD-dependent isolates reported on previously, in which the serogroup C isolates were found to be more virulent then the serogroup A isolates.

Animals↗
PubMed2002

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents--special references to bacteria isolated between April 2000 and March 2001].

Tendency of isolated bacteria from infections in general surgery and their antimicrobial susceptibilities during the period from April 2000 to March 2001 were investigated in a multicenter study in Japan, and the following results were obtained. The number of cases investigated as objectives was 234 for one year. A total of 388 strains (136 strains from primary infections and 252 strains from postoperative infections) were isolated from 165 cases (70.5% of total cases). In primary infections, anaerobic Gram-positive bacteria were predominant, while from postoperative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by that of Staphylococcus aureus from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among aerobic Gram-negative bacteria, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by Enterobacter spp. and Klebsiella spp. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. There was no vancomycin-resistant S. aureus nor Enterococcus spp. Among anaerobic bacteria, there were many resistant strains against penicillins and cephems with MICs higher than 100 micrograms/ml, and the same trend was observed among other Bacteroides spp. and Prevotella spp.

Anti-Bacterial Agents↗
PubMed1992

Incidence of Aeromonas isolated from diarrhoeal children and study of some virulence factors in the isolates.

Stool samples from 305 children with diarrhoea and equal number of age and sex matched non-diarrhoeal control children, less than 5 years of age, were examined during the period from Sept 1988 to April 1989. Aeromonas spp. were isolated from 37 (12.1%) diarrhoeal and 05 (1.6%) control cases. Out of 37 diarrhoeal isolates 13 (35.1%) were A. hydrophila, 19 (51.1%) A. sobria and 05 (13.5%) A. caviae. All the isolated strains were tested for haem agglutination property and haemolysin production. Seventeen diarrhoeal and 05 control isolates were tested for cytotoxin production in He La cell line and enterotoxin production in rat ileal loop model and suckling mouse model. Chinese hamster ovary cell (CHO) assay and Gm-1 ELISA methods were also employed. Cytotoxin production was found in 82.5% of diarrhoeal and 40% of control isolates. Haemagglutination was found in 62.1% of Aeromonas isolated from diarrhoeal children and 20% from control children. Enterotoxin production was detected in 58.8% diarrhoeal and none of the control isolates by either of the methods. Of the virulence factors enterotoxin production was found to correlate well with enteropathogenicity but haemolysin, cytotoxin and haemagglutinin did not.

Aeromonas↗
PubMed2004

[Improvement of massive human islet isolation techniques and the evaluation of isolated human islets].

OBJECTIVE: To obtain massive human pancreatic islets with modified techniques and evaluation of the islets for the clinical allo-transplantation to treat type I and II diabetes. METHODS: 28 consecutive adult human pancreata were isolated with modified automated techniques. Islets were purified using continuous density gradient. The islet yield was counted with international standard known as islet equivalent (IEQ). The function of the isolated islets was evaluated by measuring DNA/insulin ratio, static glucose stimulating test in vitro and transplanting the islets into diabetic nude mice in vivo followed by abdominal glucose tolerance test and C peptide measurement. RESULTS: The yield of 28 consecutive human pancreata isolations ranged from 5 000 to 1 030 000 IEQs/pancreas with the average of 291 635 IEQs/pancreas. The first 13 isolations yielded 49 123 IEQs/pancreas, 846 IEQs/g and, purity 87% in average. The remained 15 isolations after the modifications yielded 501 813 IEQs/pancreas, 7 003 IEQs/g and purity 89% in average. The results of in vitro SGS showed good response to the different glucose concentration. 34 diabetic nude mice were transplanted under the renal capsule with the freshly isolated islets. 29 out of 34 diabetic mice obtained normoglycemia within 12 hours and the glucose tolerance tests were near normal. Serum C peptide level of transplanted mice is close to that of the control group. CONCLUSIONS: Massive human islets can be isolated with the modified techniques. Quality assessment of these islets both in vitro and in vivo has indicated that these high quality human islets could be used for the clinical allogeneic islet transplantation.

Adult↗
PubMed1989

[Hemagglutinating activity of Escherichia coli isolated from the respiratory tract in comparison with those isolated from urine feces and blood].

Various bacteria with pili are able to agglutinate human and animal red blood cells. Hemagglutinating activity of 131 strains of Escherichia coli isolated from respiratory tract (24 strains), urine (64 strains), feces (36 strains) and blood (7 strains) were tested using human type A, guinea pig, bovine and chicken erythrocytes. Concerning the hemagglutination activity for erythrocytes from at least one of four species (human, guinea pig, bovine, chicken), the strains isolated from respiratory tract showed a higher level than those isolated from feces (p less than 0.01) or those isolated from blood (p less than 0.1). Agglutination of human erythrocytes: Of 131 strains, mannose-sensitive agglutination was observed in 31 strains, mannose-resistant agglutination in 40 strains and non-agglutination in 60 strains. More agglutinated strains were isolated from the respiratory tract than those isolated from blood but not with statistical significance (p less than 0.1). Agglutination of guinea pig erythrocytes: Of 131 strains, mannose-sensitive agglutination was observed in 56 strains, mannose-resistant agglutination in 10 strains and non-agglutination in 65 strains. More agglutinated strains were isolated from the respiratory tract than from urine, feces and blood (p less than 0.01), and of those, 89% were mannose-sensitive agglutination. Agglutination of bovine erythrocytes: Of the 131 strains, mannose-sensitive agglutination was observed in 4 strains, mannose-resistant agglutination in 6 strains and non-agglutination in 121 strains. Therefore, only a few agglutinated strains were seen.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Immunological properties of M. leprae culture isolates ICRC bacilli: hypothesis on relationship between M. leprae and ML-culture isolates.

The M. leprae-culture isolate, being a culture, is identified by biochemical criteria. Majority belong to either M. avium-intracellulare-scrofulacieum complex, or corynobacterium group. The identification is also determined by serological methods using soluble sonicates. Skin tests with heat-killed suspension often give positive Mitsuda response and hence the isolates are discarded as non-M. leprae. The data on ICRC strains show that Dharmendra type antigen prepared from ICRC bacilli compares very well with lepromin in lepromatous patients. The CMI/DTH tests in mice by FPE and LMI technique have experimentally demonstrated that ICRC bacillus is the first cultivable mycobacterium that can sensitize mice against lepromin. These data also brought out antigenic differences between the ICRC strains. The clinical trial on ICRC vaccine has shown that the ICRC bacilli is immunogenic in Man. The biochemical data on ICRC strain show that they possess DOPA-Oxidase and can express biochemical character of 9/10 similarity index with M. leprae with appropriate substrates in the medium. Thus, the ICRC strains possess both M. leprae and M. avium characters. An hypothesis is proposed to explain these observations--The 'Janus face' of M. leprae--by proposing a relationship between M. leprae and its culture isolates, e.g. ICRC bacilli (1). The M. leprae-culture isolate may by a recombinent of M. leprae with M. avium background (2). The ML-isolate may express the CMI related antigenic determinants corresponding to that of M. leprae in the biopsy (3). The CMI related antigens of whole bacilli in the ML-culture isolate may be inducing type as against only eliciting antigen expressed by M. leprae (4). Recombination may provide immunogenicity as well as 'in vitro' growth potential to the ML-culture isolate (5). Absence or failure to express inducing antigen by M. leprae maybe alternate biological escape mechanism from immune surveillance for survival in vivo, with or without suppressor mechanisms.

Animals↗
PubMed1984

[Isolation, identification and typing of Newcastle disease virus isolates in a chick embryo cell culture].

Routine methods of investigation were employed in parallel experiments for the isolation (in chick embryos), identification (serologically via HI), and typing (MDT, ICPI, IVPI, and via cloacal tests) of local isolates and standard strains of the Newcastle disease virus (NDV). The results were the same as those obtained by the single-phase complex investigation after the plaque technique method in a monolayer cell culture of chick embryo fibroblasts under agar cover. The cultures were inoculated with tissue suspension centrifugate in multiple dilutions of trachea and lung, spleen and liver, and brain of experimentally infected birds, using local isolates (13 in all) and standard strains of NDV (6 of the various types) as well as of birds that died of Newcastle disease (3 cases). The complex cell culture technique of investigation included plaque-forming under agar (and under agarose as well) following the direct inoculation with the infectious tissue suspensions in the presence of a normal (known negative), resp., specific hyperimmune serum against Newcastle disease. It also included a plaque-neutralization (plaque reduction) test and tests for hemadsorption and elution of erythrocytes--all made use of in a single planned programme of investigation. This technique, which is a modification of the one suggested by Beard et al. (1970) and known as single-phase complex plaque technique, provides the simultaneous isolation and identification of NDV isolates, which may well be coupled with some of the routinely practiced methods for definitive isolate typing (e. g., with the cloacal test for velogenic, and with MDT for lento- and mesogenic isolates). Thus, time can be saved, and labour and means are reduced, i. e., the laboratory diagnostics of ND may be perfected.

Animals↗
PubMed1996

Scope of urinary pathogens isolated in the Public Health Bacteriology Laboratory, Harare: antibiotic susceptibility patterns of isolates and incidence of haemolytic bacteria.

OBJECTIVES: To determine the scope of urinary pathogens isolated in the Public Health Bacteriology Laboratory, their antibiotic susceptibility patterns and the incidence of haemolytic bacteria in Harare. DESIGN: Prospective study. Patients of different age groups attending various clinics in Parirenyatwa Hospital, Harare, between October 1995 and April 1996 were enrolled for the study. SETTING: A laboratory based study at the Bacteriology Unit, Public Health Laboratories, Harare. SUBJECTS: 1,760 urine specimens obtained from male and female patients suspected of having UTI. RESULTS: Out of a total number of 1,760 urine specimens screened only 473 (26.9pc) were positive for UTI pathogens. Four hundred and nineteen (88.5pc) and 46 (9.7pc) of the 473 positive UTI pathogens were Gram negative and Gram positive bacteria respectively. Eight (1.7pc) of the positive isolates were Candida spp. The commonest pathogen isolated was Escherichia coli (40.5pc), followed by Klebsiella spp. (22.1pc) and Proteus spp. (7.2pc). Of the positive isolates 184 (38.9pc) and seven (1.5pc) were beta- and alpha-haemolytic respectively. Of E. coli isolates 72pc were beta-haemolytic. Sex distribution showed that 53pc and 47pc of the UTI pathogens were isolated from males and females respectively. E. coli was more predominant in females (51.3pc). Antibiotic susceptibility patterns revealed that 100pc of strains of E. coli, Proteus spp., Serratia spp., Salmonella spp., Morganella spp., Staphylococcus aureus and coagulase negative staphylococci (CNS) were sensitive to Ciprofloxacin. Urinary isolates were markedly resistant to Tetracycline, Carbenicillin, Cotrimoxazole, Ampicillin and Nitrofurantoin. Fusidic acid and Clindamycin were active against staphylococcal species. CONCLUSION: We conclude that E. coli is the commonest UTI pathogen and that 72pc of strains were beta-haemolytic. We suggest the use of Ciprofloxacin as the drug of choice for the treatment of UTI caused by both Gram positive and Gram negative UTI pathogens. Nitrofurantoin and Gentamycin are in addition recommended for E. coli while Fusidic acid and Clindamycin may be useful for staphylococcal species.

Adolescent↗
PubMed2005

Environmental reservoirs of methicillin-resistant Staphylococcus aureus in isolation rooms: correlation with patient isolates and implications for hospital hygiene.

Strategies to control and prevent the spread of methicillin-resistant Staphylococcus aureus (MRSA) include early identification of positive patients through screening, patient isolation, hand hygiene, nasal and skin decontamination, and the adequate cleaning and decontamination of clinical areas. However, many national and other guidelines provide few details on environmental decontamination regimens, partly because the role of the environment in the spread of MRSA is not well documented. We prospectively studied the environment of the isolation rooms of 25 MRSA patients for up to four weeks, sampling horizontal surfaces and the air using settle plates as well as an air sampler, while continuing regular daily cleaning according to the hospital protocol. We then typed 20 patient isolates and the corresponding environmental isolates (N=35) to assess the similarity of strains. A high proportion of samples were positive for MRSA; 269/502 (53.6%) surface samples, 70/250 (28%) air samples and 102/251 (40.6%) settle plates. Over half of the surface samples taken from the beds and the mattresses were positive for MRSA. Identical or closely related isolates were recovered from the patient and their environment in 14 (70%) patients, suggesting possible environmental contamination of the isolation rooms, possibly contributing to endemic MRSA. More effective and rigorous use of current approaches to cleaning and decontamination is required as well as consideration of newer technologies to eradicate MRSA and other hospital-acquired pathogens.

Air Microbiology↗
PubMed1998

APIC and CDC survey of Mycobacterium tuberculosis isolation and control practices in hospitals caring for children. Part 1: Patient and family isolation policies and procedures. Association for Professionals in Infection and Epidemiology, Inc.

BACKGROUND: The 1994 Centers for Disease Control and Prevention draft Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health-Care Facilities did not exempt pediatric facilities from instituting controls to prevent nosocomial tuberculosis (TB) transmission. Many researchers contend that TB disease in children does not require such rigid controls. We surveyed acute-care pediatric facilities in the United States to determine adherence to patient and family isolation policies and procedures. METHODS: The study included 4 mailings of a survey to infection control professionals at 284 US children's hospitals and adult acute-care hospitals with > 30 pediatric beds. RESULTS: The overall response rate was 69%. Only 41% of respondents reported having a written TB policy specifically designed for pediatric patients. Whereas 98% of respondents isolated pediatric patients with confirmed pulmonary TB, only 69% reported isolation of patients with miliary TB, and 79% reported isolation of patients with positive gastric aspirates. TB isolation policies for adult visitors were in place at 69% of hospitals, and 50% of hospitals evaluated adults for TB as part of the child's TB treatment plan. A median of 3 contact investigations occurred at each of 47% of respondent hospitals in the preceding 5 years. CONCLUSIONS: Isolation and infection control policies for children with pulmonary TB largely conformed to published guidelines but varied for children with nonpulmonary TB. Because the greatest risk of nosocomial TB transmission in pediatric facilities comes from adults with TB, a rapid TB screening process for parents and adult contacts accompanying affected children should be instituted at facilities caring for children.

Adult↗
PubMed2001

Patients' perceptions of methicillin-resistant Staphylococcus aureus and source isolation: a qualitative analysis of source-isolated patients.

A group of 19 individuals who had been infected with methicillin-resistant Staphylococcus aureus (MRSA) and placed in source isolation were interviewed about their views of MRSA infection and the experience of source isolation. Participants were unclear about the nature of MRSA, and generally did not perceive the infection to have a significant impact upon their life (either in terms of the presence of symptoms or in restriction of activities). Despite this, roughly half the sample thought that an MRSA infection was 'serious'. Only one participant clearly viewed their MRSA as hospital-acquired, most being uncertain about the mode of transmission or viewing it as unrelated to the behaviour of care staff. Few respondents displayed an accurate knowledge of the reasons for source isolation and barrier nursing. Isolation was viewed as having advantages and disadvantages. There was little evidence of a detrimental psychological effect of isolation. Patients infected with MRSA appear to understand little about their condition or the necessity for barrier nursing and source isolation. This has implications for understanding patients' adherence with infection control procedures.

Adult↗