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Biomedical subjects

L G Burman

Publications and source records attributed to L G Burman.

At least 91 records · Page 5Linked to original sources
PubMed1988

Epidemiology of fecal strains of the family Enterobacteriaceae in 22 neonatal wards and influence of antibiotic policy.

The gram-negative fecal floras from 953 infants were studied upon discharge of the infants from 22 neonatal wards. More than 600 distinct phenotypes of Escherichia coli, Klebsiella spp., and Enterobacter spp. were distinguished by high-resolution biotyping. The colonization patterns observed showed considerable local and temporal variation. The major (M) strains (phenotypes), which colonized more than 10% and up to 78% of the infants in a ward (median, 23%), were Klebsiella oxytoca (15 strains), E. coli (4 strains), Klebsiella pneumoniae (1 strain), and Enterobacter cloacae (1 strain). Resistance to beta-lactam antibiotics was more pronounced among M strains than among strains of enteric bacteria colonizing few or single infants only. Local antibiotic policy influenced the colonization patterns. Despite the fact that M strains of Klebsiella spp. were usually resistant to ampicillin as well as to cephalexin and cefuroxime, their local dissemination was associated with the use of ampicillin with or without gentamicin but not with the use of cefuroxime. It thus appeared that in the neonatal setting, ampicillin posed a greater risk of local spread of certain drug-resistant bacterial clones than a newer cephalosporin, such as cefuroxime.

Anti-Bacterial Agents↗
PubMed1988

Clinical and bacteriological effects of therapy of urinary tract infection in primary health care: relation to in vitro sensitivity testing.

17 primary health care (PHC) centres participated in a 1-month evaluation of a county urinary tract infection (UTI) management program. A total of 302 patients contributing 355 episodes, dominated by female (93%), lower symptomatic (75%) and Escherichia coli (74%) episodes were studied. In therapeutic failure gram-negative bacteria other than E. coli showed an increased prevalence whereas Staphylococcus saprophyticus was not found. The general pattern of drug resistance was little influenced by UTI history and the mean pretherapy prevalence of resistance to the 7 antibacterial agents studied was low (7%). Drug resistance was increased in failure (mean 24%) also for agents not used for therapy (sulphonamides and nitrofurantoin) but not in early or repeated recurrence. UTI symptoms were eradicated in only two-thirds of bacteriologically cured episodes but in one-third of the failures at the posttreatment control. On average, therapy resulted in 8% bacteriological failure and 12% early recurrence. The bacteriological cure rate was the same irrespective of whether the infecting bacteria were classified as sensitive or resistant in vitro to the drug given. Thus, sensitivity testing of isolates is rarely needed in sporadic or recurrent UTI in PHC but may be relevant in failure. In order to be of prognostic value in uncomplicated UTI high-level breakpoints focusing more on peak urinary drug concentrations need to be studied.

Adolescent↗
PubMed1988

Failure of single-dose metronidazole prophylaxis in colorectal surgery. No benefit from high dosage or combination with nalidixic acid.

In an open prospective study of postoperative infectious complications, patients undergoing elective colorectal surgery were randomly allocated to one of three groups receiving parenteral single-dose antimicrobial prophylaxis (1 g or 3 g metronidazole or 1 g metronidazole + 3 g nalidixic acid). Because of an unacceptably high rate of surgical infection in all three groups (36%, 29% and 39%, p greater than 0.1) among the first 103 evaluable patients, the study was discontinued. Nalidixic acid--though effective in in vitro tests of bacterial susceptibility--thus was found to be of little or no value as prophylaxis against Gram-negative infection. As the observed infection rate when metronidazole was given at the start of operation was seven-fold that previously found in the same department when 1 g metronidazole was administered 3-4 hours preoperatively (28/103 vs. 2/50, p less than 0.01), the timing of metronidazole prophylaxis was assumed to be potentially important for its ability to protect also against aerobic postoperative infection.

Adult↗
PubMed1987

Use of indwelling urinary tract catheters in Swedish hospitals.

In a survey of 67,774 patient days in 27 Swedish acute care hospitals, an indwelling urinary tract catheter (IUTC) was in place during 12% of patient days. There were marked differences between services (from 2% in rheumatology to 49% in urology), but also between hospitals for the same type of service (general surgery, internal medicine, gynecology, orthopaedic surgery) concerning proportion IUTC days, average duration of catheterization and the indications for IUTC use. The great local variation in IUTC usage for a particular service was usually not correlated with type of hospital (district, county, or regional/teaching), ie, with the mix of patients studied. We propose that the results mainly reflect a variable local impact of infection control and that a much more restrictive use of IUTCs is possible in many wards. This condition would imply a considerable potential for reducing the incidences of urinary tract infection and bacteremia and thus, mortality among hospitalized patients in Sweden.

Aged↗
PubMed1987

Norfloxacin versus placebo for prophylaxis against travellers' diarrhoea.

In a randomized, double blind study, 127 subjects travelling to countries outside Northern Europe were given norfloxacin 200 mg or placebo bid as prophylaxis against diarrhoea. Fifty-six subjects randomized to norfloxacin and 59 to placebo fulfilled criteria for evaluation of efficacy and of those, respectively six and 20 (P = 0.0006) developed diarrhoea. The mean duration of symptoms in the placebo group was 3.6 days, while all subjects on norfloxacin had symptoms for one day only. In travellers to Mediterranean Europe or the Canary Islands, no significant differences were seen between norfloxacin and placebo. Among subjects going to Africa, Asia or Latin America, 4/32 subjects on norfloxacin and 16/30 on placebo developed diarrhoea (P = 0.0004). Adverse effects were few and mild. Faeces for aerobic cultures was obtained before travelling and three weeks and then three months post-treatment. Treatment with norfloxacin resulted in a significant reduction of samples yielding aerobic Gram-negative rods but did not affect enterococci. In the placebo group, Gram-negative organisms other than Escherichia coli were increased on return to Sweden and the subjects frequently acquired Gram-negative organisms resistant to antibiotics. In none of the groups was there a tendency towards increased norfloxacin resistance. Biotyping of E. coli showed that in both groups the subjects changed their E. coli strains frequently during and after travelling. This trial showed that norfloxacin is a safe and effective prophylactic agent with no adverse effect on bacterial flora, but that its use should be restricted to travellers to non-European countries.

Adult↗
PubMed1987

Short-term nalidixic acid plus sodium citrate in acute lower urinary tract infection.

Low-dose nalidixic acid (0.66 g) in combination with 4 g of sodium citrate (NAC) was evaluated in acute lower UTI. In college-age females (n = 24) given NAC every 8 h for 3 days the nalidixic acid (NA) susceptible infecting strain was eradicated in 100% of the patients and recurrence during the 1 month follow-up period occurred in 1 case (5%) classified as relapse. In a following study the corresponding rates in general practice (GP) patients (n = 71) were 90% and 17%, respectively, irrespective of treatment with NAC every 12 h for 3 days or 5 days. The failures observed in GP were due to persistence of (or immediate reinfection by) the original infecting strain (4%) or its NA resistant mutant (6%). Emergence of NA resistance was associated with high age of the patient and a high incidence of NA resistant mutants in the infecting Escherichia coli strain. NA susceptible failure and recurrence during follow-up occurred primarily in younger GP patients. The recurrences were equally often classified as relapse (6 cases) as reinfection (5 cases). About 20% of the patients reported rather innocuous transient side effects of NAC and interruption of medication occurred in 1 case (0.6%).

Adolescent↗
PubMed1987

Urinary tract infection in primary health care in northern Sweden. I. Epidemiology.

During a 12-month study at the primary health care (PHC) centre in Vännäs (population 8,000) 632 encounters by 265 individuals because of suspected urinary tract infection (UTI) or control after treatment resulted in 279 episodes of bacteriuria in 185 patients. Nine per cent of the episodes concerned patients with indwelling catheter or incontinence requiring other aids. Symptoms of lower and higher UTI were recorded in 56 and 12%, respectively, whereas one third of the episodes were associated with vague or no symptoms and discovered mainly at planned treatment controls. The annual incidence of bacteriuria recorded increased from 0.5% in the first decade of life to more than 10% in the age group 90-100 years. Male UTI comprised 13% of the episodes, increased after middle age and contributed 40% at greater than or equal to 80 years of age. The risk of recurrence (on average 50% during the year studied) was relatively independent of sex and age. No seasonal variation of UTI was observed except for a peak in late summer due to Staphylococcus saprophyticus confined to females aged 15-64 years and causing 28% of the episodes in August. Although UTI in PHC appears to be similar globally it represents a far more complex patient group than indicated by the UTI drug trials frequently published.

Adolescent↗
PubMed1987

Urinary tract infection in primary health care in northern Sweden. II. Clinical presentation.

In a multipractice prevalence study of uncomplicated urinary tract infection (UTI) in primary health care (PHC), with 355 episodes in 302 individuals during one month, 93% of the episodes occurred in females and Escherichia coli was the dominating causative organism (77%). Most episodes of UTI (84%) were acute and associated with lower (75%), upper (5%) or uncharacteristic symptoms (4%) whereas 16% represented bacteriuria discovered by posttreatment controls. Urgency (77%) and dysuria (70%) were the most common symptoms. Loin pain was highly associated with upper UTI (88%) but was reported also in 23% of episodes of lower UTI. Patient's delay differed between PHC centres and patient categories and was surprisingly long, four weeks in nine per cent and on average 8.4 days.

Adolescent↗
PubMed1987

Urinary tract infection in primary health care in northern Sweden. III. Bacteriology in relation to clinical and epidemiological factors.

The spectrum of bacteria causing urinary tract infection (UTI) and their patterns of drug resistance were found to be more associated with the process of selecting the patients and their sex and age than with the symptoms of the patient (lower, upper or asymptomatic UTI). UTI caused by Staphylococcus saprophyticus was seen mainly in female patients in primary health care (PHC), showed a peak in August and was rarely complicated by therapeutic failures or recurrences. The average risk of resistance of the infecting strain to the seven drugs tested increased from eight per cent for the uncomplicated and 17% for the average PHC patient to 36% among PHC patients with indwelling catheter or urinary incontinence, whereas recurrences of UTI were associated with a surprisingly small increase of drug resistance. In all UTI patient groups studied, the lowest incidences of bacterial resistance were recorded for trimethoprim and co-trimoxazole (0-17%). Thus, rational selection of UTI therapy in PHC requires knowledge of the influence of clinical factors on the expected bacteriology including the local pattern of drug resistance.

Bacteria↗
PubMed1986

The antimicrobial activities of trimethoprim and sulfonamides.

The folate inhibitor trimethoprim (TMP) is active against and potentially cidal to a few higher microorganisms and a wide spectrum of pathogenic bacteria except for Bacteroides, Branhamella, Brucella, Chlamydia, Clostridium, Mycobacterium, Mycoplasma, Nocardia, Neisseria, Pseudomonas and Treponema. These organisms tend to be more sensitive to sulfonamides (SUL) than to TMP, whereas TMP is 10- to 100-fold more active than SUL against most other bacteria. Synergy between TMP and SUL occurs at drug concentrations equal to or less than their respective MICs and is often seen in vitro with isolates that are sensitive or moderately resistant to one or both of the components. Synergy occurs over a wide range of ratios between TMP and SUL, the optimal being that between their respective MICs when acting singly. In vitro synergy is more impaired by bacterial resistance than by suboptimal TMP:SUL ratios. The vast majority of clinical isolates of Haemophilus, staphylococci, streptococci and enteric bacteria are inhibited in vitro by the minimum concentrations of drug attained in plasma during therapy. Exceptions are found among Enterobacter, Citrobacter, Serratia, Proteus and in particular Klebsiella where SUL resistance is common and isolates with TMP MICs of 5 mg/l or more may occur and lead to failure of TMP-SUL therapy in systemic infections. In the urinary tract drug concentrations that are synergistic and therefore inhibitory in vitro against isolates moderately resistant to SUL (MIC less than or equal to 1 g/l) and/or TMP (MIC less than or equal to 0.1 g/l) are present during TMP-SUL therapy. However, whether the synergy and the bactericidal effect of TMP-SUL observed in vitro play a role in vivo is controversial.

Bacteria↗
PubMed1986

Significance of the sulfonamide component for the clinical efficacy of trimethoprim-sulfonamide combinations.

The reasons for combining trimethoprim (TMP) with sulfonamides (SUL) are still mainly theoretical but are supported by results from experimental infections and treatment of specific pathogens in humans, such as Branhamella catarrhalis, Neisseria gonorrhoeae, Brucella, Nocardia asteroides and perhaps Bordetella pertussis and Chlamydia trachomatis. Addition of SUL to TMP confers a therapeutic advantage also in patients with complicated urinary tract infection but probably not in young women with acute cystitis. Conditions that may enable TMP-SUL synergy in vivo can be expected to occur only in occasional cases of infection due to staphylococci, streptococci, Haemophilus or enteric bacteria. This fact together with ethical problems and availability of alternative therapies make further evaluations of the clinical significance of the SUL component of TMP-SUL very difficult. Although the use of TMP alone has shown promise in exacerbations of chronic bronchitis the role of the SUL component in TMP-SUL treatment of infections outside the urinary tract remains to be defined in comparative clinical trials.

Aged↗
PubMed1985

Anaerobic phagocytosis, killing, and degradation of Streptococcus pneumoniae by human peripheral blood leukocytes.

Encapsulated Streptococcus pneumoniae of serotypes 2, 9N, 14, 21, and 23F and an unencapsulated variant of type 2 pneumococci were efficiently phagocytosed by both aerobically and anaerobically incubated human leukocytes. In the presence of O2, the pneumococci rapidly lost their viability, whereas during anaerobiosis, killing was considerably delayed. Type 14 pneumococci radiolabeled with [14C]choline or [14C]ethanolamine for cell wall teichoic acid, [14C]uracil for nucleic acids, or [14C]arachidonic acid for unsaturated cytoplasmic membrane lipids were used in studies of the fate of bacterial macromolecules after phagocytosis. The degradation of teichoic acid, RNA, and DNA during anaerobiosis approached that recorded in air at 60 min of incubation (45 to 70% and 55 to 75%, respectively). In contrast, the marked loss of [14C]arachidonic acid from pneumococcal membrane lipids observed in aerobic leukocytes did not occur during anaerobic incubation. Hence, lipid peroxidation could be involved in the rapid aerobic leukocyte killing of pneumococci, whereas a different leukocyte function of as yet unknown nature appears to be responsible for the killing seen in anaerobiosis. Autolysis-resistant type 14 pneumococci were obtained by substituting ethanolamine for choline in a defined culture medium. Differences between such bacteria and normal (autolytic) pneumococci in their killing and degradation by leukocytes were not detected in either the presence or the absence of O2. The aerobic and anaerobic handling of phagocytosed pneumococci by human blood leukocytes thus proceeded independently of the bacterial autolytic system.

Aerobiosis↗
PubMed1985

Prevention of post-operative infection in appendicectomy by single dose intravenous metronidazole. An open prospective randomised study.

In an open prospective randomized study of appendicectomy, single-dose (1 g) intravenous metronidazole prophylaxis (and continued metronidazole plus nalidixic acid in perforated appendices) resulted in a lower overall post-operative infection rate (1.4%) than no prophylaxis and doxycycline therapy in the case of perforation (16%, p less than 0.025). In patients with an unperforated appendix no infections occurred after single-dose metronidazole prophylaxis as opposed to 8.2% infections in untreated controls (p less than 0.025).

Adolescent↗
PubMed1985

Single-dose intravenous metronidazole v. doxycycline prophylaxis in colorectal surgery. An open prospective, randomized trial.

In an open prospective, randomized study of antimicrobial prophylaxis in colorectal surgery, using a single intravenous dose, metronidazole (1 g) was more effective than doxycycline (0.2 g). The difference in infection rates (2/41 = 5% v. 7/33 = 21%) was statistically significant. Prolonged administration of either agent (2-7 days) yielded results comparable to those with single doses. Five emergency cases were admitted to the study. In two of them, a metronidazole-based therapeutic regimen prevented postoperative infection, whereas infection occurred in all 3 patients given doxycycline therapy. The total infection rate after elective surgery was 4% with metronidazole and 25% with doxycycline prophylaxis. The infections in the metronidazole group were superficial and caused by Escherichia coli, whereas half of the infections in the doxycycline group were intra-abdominal and due to intestinal aerobic and/or anaerobic bacteria. In contrast to doxycycline, therefore, metronidazole prevented postoperative anaerobic infection and was associated with low incidence of aerobic infection.

Adult↗
PubMed1984

Molecular model for elongation of the murein sacculus of Escherichia coli.

Labeling experiments are presented that suggest that new (radioactive) strands of murein are initially inserted adjacent to old strands. After 8 min, new strands start to be inserted adjacent to the previously inserted radioactive strands. Analysis of these data suggests that, for Escherichia coli to double the length of the sacculus in each generation, about 90 separate membrane-bound enzyme complexes travel unidirectionally around the circumference of the cell. They travel at a constant rate, six times each generation, synthesizing, inserting, and crosslinking two strands of murein at a time, thereby doubling the length of the sacculus.

Escherichia coli↗