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Biomedical subjects

Mattias Larsson

Publications and source records attributed to Mattias Larsson.

7 recordsLinked to original sources
PubMed2005

Extended antimicrobial resistance screening of the dominant faecal Escherichia coli and of rare resistant clones.

Fifty faecal samples from healthy adults were grown on MacConkey agar and three pink colonies were subcultured, identified to species level and their antimicrobial susceptibility determined. Forty-seven samples yielded 141 isolates of Escherichia coli that were susceptible to most antimicrobials. Resistance was noted for ampicillin (30.5%), chloramphenicol (12.1%), tetracycline (23.4%), trimethoprim (24.8%) and co-trimoxazole (22.7%). A direct faecal plating method was used for extended resistance screening with E. coli as the indicator organism. Zone breakpoints were determined using normalised resistance interpretation and gave similar susceptibility results. Eighty-eight isolates of E. coli from within the zones of inhibition revealed four times more antimicrobial resistance. Extended antimicrobial resistance screening both provides the susceptibility profile of the dominant E. coli isolate and detects greater resistance in rare isolates.

Ampicillin↗
PubMed2005

Evaluation of a rapid screening method for detection of antimicrobial resistance in the commensal microbiota of the gut.

The assessment of antimicrobial resistance among commensal bacteria is an indicator of the spread of antimicrobial resistance. Rapid screening methods for detection of antimicrobial-resistant faecal Escherichia coli directly on MacConkey plates have been successfully adopted but suffer from lack of standardisation. The purpose of this study was to evaluate a direct plating method (DPM) for detection of antimicrobial-resistant faecal E. coli and to compare it with a conventional method. Faecal samples were collected from 71 healthy children from Peru and Bolivia. In the DPM, a faecal swab was directly plated onto a MacConkey agar plate and antimicrobial disks were applied onto the seeded plate. Raw data were obtained by direct reading of the plate and were subjected to confirmatory analysis. Good concordance between the DPM and a conventional method was observed in detecting carriage of resistant E. coli, with a higher sensitivity for the DPM. Analysis of the results allowed interpretive criteria to be defined for DPM raw data. The DPM showed good sensitivity and specificity at very low cost (ten times cheaper than the conventional method) to investigate the faecal carriage of drug-resistant E. coli. It may represent a useful tool to conduct large-scale resistance surveillance studies and to monitor resistance control programmes cost effectively, particularly in low-resource countries.

Bacteriological Techniques↗
PubMed2005

Acquired sulphonamide resistance genes in faecal Escherichia coli from healthy children in Bolivia and Peru.

Antimicrobial resistance and sulphonamide resistance determinants were studied in 20 co-trimoxazole resistant Escherichia coli in faecal samples from healthy children in Bolivia and Peru. Methods used were disc diffusion susceptibility tests, PCR, sequence analysis and plasmid conjugation assays. All isolates but one were resistant to at least two different classes of antimicrobials; 19 isolates also carried at least one sul-gene. The most frequent gene was sul2 followed by sul1 and sul3, which was detected in one isolate. This is the first observation of sul3 on the American continent. In conclusion, the high prevalence of sul-genes in this material of faecal commensal E. coli isolates points to a potential role of the faecal flora in the emergence and spread of antimicrobial resistance.

Anti-Infective Agents↗
PubMed2005

Overprescribing of antibiotics to children in rural Vietnam.

100 children (aged 1-6 y), who received an antibiotic prescription after health examination in the Bavi health care system (79 children at a district hospital, 21 at a community health centre) were analysed regarding antibiotics prescribed in relation to serum C-reactive protein (CRP). A control group consisted of 35 healthy children. Children who had been treated with antibiotics within 1 week prior to the study were excluded in the community health centre and control groups. Capillary blood samples were collected and the serum CRP concentration was analysed. A questionnaire interview with the carers was performed. Elevated CRP concentrations (>10 mg/l) were detected in 17 (17%) of the study population, and only 2 had a CRP level above 25 mg/l, one 36 mg/l and the other 140 mg/l. In the control group, none of the children had elevated CRP. The most common diagnoses were acute respiratory tract infection (ARI, 55%), asthma (7%), tonsillitis (4%), and diarrhoea (4%). The average number of drugs per patient was 3.1, and 77% received vitamins and 15% corticosteroids in combination with antibiotics. A majority of children who received an antibiotic prescription based on clinical examination did not have an elevated CRP and overprescribing of antibiotics was thus indicated.

Anti-Bacterial Agents↗
PubMed2003

Supramolecular control of two-dimensional phase behavior.

We have used directed two-component self-assembly to "pattern" organic monolayers on the nanometer scale at the liquid/solid interface. The ability of the scanning tunneling microscope to investigate structural details in these adlayers was used to gain insight into the two-component two-dimensional phase behavior. The components are symmetrically alkylated bisurea derivatives (R1-urea-spacer-urea-R2; R1, R2=alkyl, spacer=alkyl or bisthiophene). The bisthiophene unit acts as a marker and its bisurea derivative (T2) is a component in all the mixtures investigated. By varying the position of the hydrogen-bond forming urea groups along the molecule and the length of the alkyl chains of the other components, the effect of 1) hydrogen bonding, 2) molecule length, 3) odd-even effects, and 4) shape complementarity on the two-dimensional phase behavior was investigated. Insight into the effect of these parameters leads to the control of the two-dimensional patterning: from randomly intermixed systems to phase separation.

Journal Article↗
PubMed2002

Improving private pharmacy practice: a multi-intervention experiment in Hanoi, Vietnam.

The objective of this study was to assess the effects of a multicomponent intervention on private pharmacy practice. From 641 private pharmacies in Hanoi, 68 pharmacies were randomly selected and matched into 34 pairs. Each pair consisted of a control and an intervention pharmacy. Three interventions were applied sequentially: Regulatory enforcement, Education, and Peer influence. Four tracer conditions were selected: uncomplicated acute respiratory infection (ARI), sexually transmitted disease (STD), requesting the prescription-only drugs prednisolone, and a short course of cefalexin. Practice was assessed through the Simulated Client Method (SCM). The intervention pharmacies improved significantly compared to the control pharmacies (P <.05) in all tracer conditions. For ARI, antibiotic dispensing decreased (P <.02) and questions regarding breathing increased (P <.01). For STD, advice to go to the doctor and dispensing the correct syndromic treatment increased (P <.01). Dispensing of prednisolone and cefalexin decreased (P <.01) and prescription requests increased (P <.01). Our conclusion is that it is possible to improve private pharmacy practice with a multicomponent intervention.

Anti-Bacterial Agents↗