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Biomedical subjects

J Prag

Publications and source records attributed to J Prag.

At least 37 records · Page 2Linked to original sources
PubMed1997

Subcutaneous lesions and bacteraemia due to Stenotrophomonas maltophilia in three leukaemic patients with neutropenia.

Subcutaneous lesions were seen in three of 13 neutropenia patients who had Stenotrophomonas (Xanthomonas) maltophilia bacteraemia. The characteristic clinical presentation resembled leukaemic infiltrates, and were different from deep ulcers or subcutaneous nodules caused by Pseudomonas aeruginosa. The three patients had acute leukaemia and were treated with intensive combination chemotherapy. All had previously been treated with broad-spectrum antibiotics, and each patient recovered after proper combination antibiotic treatment given according to sensitivity testing.

Adult↗
PubMed1997

Mycoplasma in urine and blood following catheterisation of patients undergoing vascular surgery.

OBJECTIVES: The purpose of this investigation was to determine if mycoplasmas enter the bloodstream after urinary tract catheterisation in patients undergoing vascular surgery in order to evaluate the efficiency of the routine prophylactic antibiotic treatment. DESIGN: Prospective study. MATERIALS AND METHODS: A total of 100 patients (63 men and 37 women) undergoing elective vascular surgery had urine and blood cultures performed for mycoplasmas. Blood cultures were taken preoperatively after urinary tract catheterisation and the urine was collected during catheterisation. The median age of the patients was 67 years (range 42-87). RESULTS: A total of 12 (12%), 5 men and 7 women, had a positive urine culture for mycoplasmas (One patient had Mycoplasma hominis and 11 had Ureaplasma urealyticum isolated). Their median age was 60 years (range 42-76). No blood cultures were positive for Mycoplasma. CONCLUSIONS: Mycoplasmas do not enter the blood-stream after catheterization in sufficient amounts and sufficiently often to be detected by blood-cultures in this small patient sample. The number of vascular patients harbouring mycoplasmas in the urine was low and we found no indication for changes in the prophylactic antibiotic treatment based on these findings.

Adult↗
PubMed1996

[Vibrio vulnificus infections in Denmark during the summer of 1994].

The clinical manifestations and epidemiological data of 11 patients infected with Vibrio vulnificus found in Denmark during the unusually warm summer of 1994 are reported. All patients had been exposed to seawater prior to illness, but none had consumed seafood. Nine patients, including four with bacteraemia, developed skin manifestations of various degrees of severity. One patient died of septic shock despite surgery and treatment with relevant antibiotics. Four patients contracted the disease while fishing. High seawater temperature increases the risk of V. vulnificus infections even in temperate climates such as the Danish. Exposure to seawater, including handling of fresh seafood, during warm periods carries a risk of infection with V. vulnificus.

Adolescent↗
PubMed1996

High rate of nasopharyngeal carriage of potential pathogens among children in Greenland: results of a clinical survey of middle-ear disease.

Nasopharyngeal and middle-ear colonization with bacteria and viruses, including Mycoplasma pneumoniae and chlamydiae, was investigated in a survey of 54 children with acute otitis media (AOM) and 201 control children without AOM in Greenland. In total, 98% with AOM and 91% without AOM carried potentially pathogenic bacteria in the nasopharynx. Two or more potentially pathogenic species were carried by 78% with AOM and 57% without AOM. Haemophilus influenzae was found in 92% and 77%, respectively, but only Streptococcus pneumoniae was found significantly more often in the nasopharynx of children with AOM than in age-matched controls (P < .03). The two species were found in 22 of 24 ear-discharge specimens. Nine children (three with AOM) had chlamydiae in the nasopharynx, and seven of them reported rhinitis. Enteroviruses or rhinoviruses were detected in 23 nasopharyngeal specimens from 39 children with AOM, in 13 such specimens from 39 children without AOM (P = .040), and in 4 of 14 ear-discharge specimens. The potentially pathogenic load in the nasopharynx was massive, suggesting an association with the high prevalence of otitis media among children in Greenland.

Bacterial Infections↗
PubMed1995

Evaluation of staphylococci isolated from a blood culture system (Colorbact).

During a one-year period, all blood cultures positive for staphylococci from two of the smaller Danish counties with non-university hospitals only were evaluated. The isolates were speciated and coagulase-negative staphylococci (CoNS) were biotyped. Furthermore, antibiogram, phage typing and lectin typing were performed for all isolates. Clinical information was obtained by telephone, and before any bacteriological identification was performed, a preliminary judgment was made as to whether the positive blood culture was of clinical significance. A total of 3,500 blood cultures were evaluated and 426 (12.2%) were positive. One hundred and sixty blood cultures from 137 patients contained staphylococci; 36 of these patients had a pure culture of Staphylococcus aureus. One hundred and twenty-four CoNS were found and identified as S. epidermidis (81), S. hominis (19), S. haemolyticus (8), S. simulans (1), and Micrococcus species (3), and another 12 staphylococcal isolates which could not be identified to species level. A total of 35 patients had mixed cultures, including 6 with S. aureus as one of the isolates and 15 with mixed CoNS. Clinical relevance was estimated in 90% of cases where the later bacterial identification showed S. aureus, whereas clinical relevance was absent in the majority of cases including CoNS. Methicillin and gentamicin resistance was absent among S. aureus, but frequent among CoNS, especially S. epidermidis, where 40% were resistant to methicillin and 30% to gentamicin.

Bacteremia↗
PubMed1994

Bacteremia in HIV-positive and AIDS patients: incidence, species distribution, risk-factors, outcome, and influence of long-term prophylactic antibiotic treatment.

From a cohort of 837 adult, mainly homosexual HIV-infected patients, 76 bacteremic/fungemic episodes were identified in 63 patients over a 5-year period. Compared with an age-matched reference population with an incidence of 10.3 bacteremias/10,000 person-years, the incidence was 170 among pre-AIDS (p < 0.001) and 3,200 among AIDS patients (p < 0.001). Staphylococcal infections comprised 35% of all episodes, while the HIV-related pathogens Streptococcus pneumoniae, Salmonella spp. and C. neoformans together accounted for 34%. The overall mortality associated with clinical bacteremia was 12%, but nil for Salmonella spp. and S. pneumoniae. Predisposing factors for the infection were: low CD4 count (< 100 x 10(6)/l) in 71%, permanent intravenous line, 44%; neutropenia, 11% and active intravenous drug abuse, 7%. Hence, in this population, intensified hygienic precautions for intravenous lines should be the primary target for intervention. Long-term cotrimoxazole prophylaxis may prevent bacteremia with S. pneumoniae and Salmonella spp.

AIDS-Related Opportunistic Infections↗
PubMed1991

Should aerobic blood cultures be shaken intermittently or continuously?

Stationary incubation of aerobic blood cultures was compared with intermittent shaking in aerobic Vacutainer 2630 bottles with agar slants during the first 24 h, and was simultaneously compared with the continuously shaken aerobic Bactec 6A bottles as a reference system. Intermittent shaking did not significantly increase or decrease the seven days yield of the Vacutainer bottles as compared with the continuously agitated Bactec 6A bottles. When one of 604 paired Vacutainer bottles was agitated for eight h and the other incubated stationary, the speed of growth detection was significantly greater in the agitated bottle (p less than 0.001), but significantly less than with continuously agitated Bactec 6A bottles (p less than 0.001). Agitation for 14 h showed the same pattern of detection speed. These results suggest that it is desirable initially to agitate aerobic blood cultures either intermittently or continuously.

Aerobiosis↗
PubMed1991

Darkening of haemoglobin in simulated, continuously agitated aerobic blood cultures: an early indicator of bacterial growth.

The change of purple oxyhaemoglobin to the darker reduced haemoglobin and methaemoglobin was used as an initial visual growth indicator in continuously agitated, aerobic Colorbact bottles after inoculation with a broad assortment of aerobic and facultatively anaerobic bacteria previously isolated from blood cultures. Growth of all the faster growing strains could be detected by darkening of the blood cultures within a 24 h period of agitation, after they had stood unshaken for eight h. The darkening was accompanied by consumption of O2 and acidification of the fluid media. The slower growing bacteria were detected by turbidity. This growth detection method is easy, quick, inexpensive and reliable, and is especially promising for application in clinical microbiological departments which daily receive blood cultures from peripheral hospitals.

Aerobiosis↗
PubMed1991

Colorbact, a visually read blood culture system using darkening of haemoglobin in aerobic blood cultures as an early growth indicator, compared with Bactec 6A and 7A.

Colorbact-A (aerobic), a blood culture system using darkening due to oxygen reduction and acidification of haemoglobin as an initial growth indicator during the first day of incubation of continuously agitated, aerobic blood cultures, was compared with the 24 h agitated aerobic Bactec 6A in 1767 consecutive paired cultures. Both systems were examined simultaneously twice daily during the first two days and once daily the next five days of incubation. In addition, during the agitation period Colorbact-A was observed for darkening four to five times during day duty between 8 a.m. and 4 p.m. The final seven days detection rate found by Colorbact-A using observation for darkening during initial agitation was similar to the rate found by Bactec 6A for both clinically significant strains and "contaminants", but Colorbact-A was significantly faster (p less than 0.001) in finding clinically significant strains. Colorbact-AN (anaerobic) was more rapid (p less than 0.01) and yielded more positive cultures than the anaerobic Bactec 7A. The Colorbact system was flexible, inexpensive, reliable and especially promising for laboratories which receive blood cultures from other hospitals once daily, as many positive cultures can be found immediately on arrival undisturbed by agitation during transport.

Aerobiosis↗
PubMed1991

Ceftriaxone vs. ampicillin + metronidazole as prophylaxis against infections after clean-contaminated abdominal surgery.

In a prospective, controlled, double-blind study, 496 patients undergoing abdominal surgery were given antibiotic prophylaxis with a single dose of either ceftriaxone or ampicillin + metronidazole. No significant intergroup difference was found between the respective overall rates of infectious complications (3.2% and 4.9%). Analysis of the microbiologic findings showed incisional wound infections, mainly caused by gram-negative rods, to be more common in the ampicillin-metronidazole group, whereas deep wound infections were more frequent in the ceftriaxone group. It is concluded that ceftriaxone seems to be more efficient than ampicillin-metronidazole as prophylaxis against incisional wound infection, but should preferably be supplemented with an antianaerobic agent to prevent deep wound infections.

Abdomen↗
PubMed1990

[Advice on intravenous treatment with beta-lactams].

Beta-lactams (BL) are administered at present in dosages which are based only partly on controlled clinical investigations as these are difficult to carry out for all types of infections. Investigations of well-defined infections and animal experiments suggest that the optimal effect is obtained when the BL concentration is kept above the minimal inhibiting concentration (MIG) during treatment. In cases of intermittent BL treatment of serious infections and treatment of patients with compromised immune defence, it is considered advisable to keep the serum concentration constantly above the anticipated limit of sensitivity or MIC. On the basis of a review of the most important pharmacokinetic properties of BL, methods of measurement of the sensitivity of bacteria to BL and development of bacterial resistance to BL, a method is presented of calculating the individual doses and the intervals between doses as regards the sensitivities of the commonest human pathological bacteria to BL although the proposed dosages have not been tested clinically for all types of infections. Employing this, BL may easily be administered individually according to the severity of the infection and possible special conditions in the underlying disease in the patients. The individual doses and intervals between doses recommended in The Danish Medical Codex from 1988 are presented in tabular form and are compared with calculations of the time in which the serum concentration remains above the anticipated limit of sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Cephalosporins↗
PubMed1990

Comparison between Bactec Nr. 660 and a conventional 12-tube blood culture system.

The detection power of the automated blood culture system Bactec NR 660, based on infrared detection of carbon dioxide in an agitated aerobic medium and a non-agitated anaerobic medium, was compared with that of our conventional 12-tube blood culture system. Of 1685 paired blood cultures, 258 (15.3%) were positive in one or both systems. Clinically relevant isolates were found in 11.5%. The dominating species were Escherichia coli(41%), followed by Staphylococcus aureus(14%) and Klebsiella spp.(8%). The Bactec system detected 178 (10.6%) and the 12-tube system 157 (9.3%) clinically relevant microorganisms after seven days' incubation. Significantly more clinically relevant isolates were detected by the Bactec system alone as compared with the conventional system alone (40 versus 19, p less than 0.01). The detection time was significantly shorter in the Bactec system for all isolates and for E. coli and S. aureus separately (p less than 0.01). 1.8% of the isolates in the Bactec system and 2.1% in the 12-tube system were considered clinically non-relevant contaminants.

Autoanalysis↗
PubMed1989

[Clostridium septicum and colonic cancer].

During the period 1980-1987, Clostridium septicum was identified at Statens Seruminstitut, from anaerobic blood cultures in six patients. Five of the patients had cancer of the colon or rectum (c. coli) and one had cancer of the ovary. Correspondingly great incidence of solid tumours, particularly c. coli with C. septicum infection without preceding trauma or compromizing of immunity has been reported in the literature. Meticulous bacteriological identification should be undertaken on anaerobic culture as the finding of C. septicum in the blood should instigate investigation for c. coli or another form of solid tumour if no other explanation for the infection is available.

Aged↗
PubMed1989

Development of erythromycin-resistance in Staphylococcus aureus as a consequence of high erythromycin consumption.

In a mixed ward for skin and venereology patients the erythromycin consumption was 6-8 fold higher than in other wards at the same hospital. Erythromycin-resistance occurred in 15.5% of the infecting Staphylococcus aureus strains isolated from this ward, compared with 3.5% in other wards of the hospital and 2.3% in Denmark as a whole. The resistant strains belonged to different phage-type patterns, but 18 out of 19 strains contained a 1.5 MDa plasmid and had an erythromycin-inducible resistance mechanism. Erythromycin resistance was frequent (approximately 10%) among Danish S. aureus strains in the years 1963 to 1969, mainly due to the spread of multiply-resistant strains of the 83A complex. During the last ten years, however, only 1-2% of the strains have been resistant, but a slow increase in resistance has taken place during the last three years among strains of all phage patterns including strains of group II, the 94, 96 complex and type 95.

Bacteriophage Typing↗
PubMed1988

Comparative analysis of two blood culture systems (Isolator and a 12-tube system) by cumulative differences in detection power at different times during incubation.

A lysis-centrifugation blood culture system (Isolator) and a conventional system (4 tubes of nutrient broth, 4 tubes of semisolid agar, and 4 tubes of thioglycollate agar) were compared after different lengths of incubation by cumulative scoring of differences in detection power. After the first half day of incubation, the Isolator system was already significantly faster in detecting isolates of clinical significance (15 vs. 4, P = 0.02). Maximum difference in first or only detection system was seen after two days of incubation and was based on an overall superior detection of Staphylococcus aureus (11 vs. 0, P = 0.001), and an earlier detection of Enterobacteriaceae (30 vs. 13, P = 0.01) in the Isolator system. On the contrary, the detection of Streptococcus pneumoniae was significantly inferior in the Isolator system (0 vs. 10, P = 0.002). The earlier finding of clinically significant microorganisms in the Isolator system certainly contributes to good patient-care. A drawback of the Isolator system was the finding of clinically insignificant coagulase-negative staphylococci in 11%, compared with 1% in the conventional system. This led to a considerable waste of time and materials in the laboratory. The comparison of the two blood culture systems, based on statistical analysis of cumulative differences in detection power, expressed as the earliest or only findings, gives the optimal information, and is in our opinion the clinically most relevant comparison.

Bacteria↗
PubMed1987

Double-antibody sandwich enzyme-linked immunosorbent assay for rapid detection of toxin-producing Corynebacterium diphtheriae.

An enzyme-linked immunosorbent assay for determining the toxigenicity of Corynebacterium diphtheriae is presented. The assay uses hyperimmune horse diphtheria antitoxin as a capture antibody and mouse monoclonal diphtheria antitoxin as a detecting antibody. Growth of bacteria and capture of diphtheria toxin by antitoxin are carried out in one step. Toxin produced by as little as 100 toxin-producing corynebacteria is detectable, corresponding to a sensitivity of 10 ng of diphtheria toxin per ml. Demonstration of toxin after incubation of the bacteria for 4.75 h, as well as after 18 h, was in accordance with the modified Elek gel diffusion method and the guinea pig inoculation test. However, heavy inocula incubated overnight produced significantly lower optical density than did diluted inocula; thus, the higher optical density was used as an indicator of toxin production. A decrease in optical density was also seen by shortening the incubation time. For laboratory safety, ethanol was added to the microtiter plate wells before washing out of the bacteria. This resulted in a further decrease in optical density. Using 4.75-h incubation time gave a single false-negative result. No false-positive results were ever seen. Incubation for 18 h is suitable for large-scale screening, and 4.75 h of incubation is suitable for rapid identification of toxin-producing C. diphtheriae.

Corynebacterium diphtheriae↗
PubMed1986

The beta-lactamase stability and in vitro activity of cefotetan; a comparison with 8 other beta-lactam antibiotics and gentamicin.

The antibacterial activity of cefotetan, 8 other beta-lactam antibiotics and gentamicin, was tested in vitro on 288 recently isolated bacteria. The activity of cefotetan was generally higher than the 2.generation cephalosporin cefuroxime and lower than the 3.generation cephalosporins tested. In addition, cefotetan was shown to have some antibacterial activity against anaerobic bacteria. Cefotetan is a cephamycin and was found resistant to all 14 plasmid-mediated and 2 chromosomally-mediated beta-lactamases. With its beta-lactamase resistance and antibacterial activity, cefotetan seems to be a "second-generation-like" cephalosporin, almost with 3.generation cephalosporin antibacterial activity against Enterobacteriaceae.

Anti-Bacterial Agents↗