A decade of Rural Clinical School research: a PubMed review.

INTRODUCTION: One parameter of the operational framework of the Australian Rural Clinical Training & Support Program (RCTS) is rural health research, yet there are no published reports of the research outcomes generated by these hallmarks of Australian rural medical education. To assess the contribution of RCTS to rural health research, their MEDLINE-indexed research publications over the last decade was analysed, using a bibliometric method. METHODS: MEDLINE-indexed RCTS publications from 2004 to 2013 were retrieved using validated PubMed queries. Two authors independently checked all retrieved RCTS publications for validity. Australian rural health (ARH) publications from RCTS were selectively enumerated and their proportion among all Australian rural health publications in each year was determined. ARH publications were defined as Australian publications that explore issues relevant to the health of the regional, rural or remote Australian population.RCTS publications related to medical education, Indigenous health, rural service areas, National Health Priority Areas (NHPA), and National Rural Health Alliance Priority Areas (NRHAPA) were analysed. Frequency of publication in different journals was also compared. RESULTS: A total of 280 RCTS publications were retrieved, increasing from 10 in 2004 to 49 in 2013. ARH topics dominated (177 articles; 67%). RCTS rural health publications increased as a proportion of all ARH publications from 3.4% in 2004 to 7.7% in 2013. Other RCTS publications increased from 2 (20% of total) in 2004 to 19 (39% of total) in 2013, and covered topics such as mental health, cancer, diabetes, obesity and asthma. RCTS medical education publications increased from 3 in 2004 to 14 in 2013. In total, 81 articles were retrieved comprising 28.9% of all RCTS publications. Indigenous health (18; 6%), rural populations (37; 13%) and rural health services (83; 29%) were the other important categories relevant to the RCTS funding parameters. RCTS publications also included NHPA (57; 20%) and NRHAPA (61; 22%). The main journals publishing RCTS research in this time period were Rural and Remote Health (16%), Australian Journal of Rural Health (13%) and Australian Family Physician (9%). RESULTS: This first study to report on the research efforts of RCTS researchers has shown that they are making a valuable contribution to rural health research and increasingly so within the research parameters indicated. These data represent a benchmark of research strengths and highlight research areas that should be strengthened with targeted research to best promote the health of rural Australians.

Distribution of the blaTEM gene and blaTEM-containing transposons in commensal Escherichia coli.

OBJECTIVES: The context of antibiotic resistance genes can provide valuable information about the epidemiology of mobile genetic elements. This study examined the distribution of the closely related blaTEM transposons Tn1, Tn2 and Tn3, or blaTEM-containing fragments of them, in ampicillin-resistant human commensal Escherichia coli isolates. METHODS: A PCR mapping protocol was used to detect different segments of the transposons or to link partial copies to the insertion sequence IS26. Restriction digestion of one amplicon was used to assign transposons to Tn1, Tn2 or Tn3 groups and sequencing validated this approach. Restriction digestion and sequencing were used to determine how much of the transposon remained when blaTEM was linked to IS26. Sequences were compared with those in GenBank. RESULTS: Of 25 ampicillin-resistant E. coli strains recovered from the faecal flora of healthy humans that carried the blaTEM gene, 15 carried a complete copy of Tn2 or a Tn2 variant; one was interrupted by IS4. A further isolate carried Tn3. Tn2 was also most abundant in sequences available in GenBank. Two isolates carried Tn2 and an IS26-blaTEM fragment. The remaining 10 isolates carried only the blaTEM end of the transposon and 9 of these partial copies were flanked by IS26 at varying distances upstream of blaTEM. One configuration corresponded to that in Tn6029B and the complete transposon was shown to be present. CONCLUSIONS: Tn1, Tn2 and Tn3 can be simply and rapidly identified. Tn2 appears to be the most widely distributed. However, the blaTEM-containing end associated with an IS26 is also widely distributed.

Commensal Escherichia coli of healthy humans: a reservoir for antibiotic-resistance determinants.

This study examined in detail the population structure of Escherichia coli from healthy adults with respect to the prevalence of antibiotic resistance and specific resistance determinants. E. coli isolated from the faeces of 20 healthy adults not recently exposed to antibiotics was tested for resistance to ten antibiotics and for carriage of integrons and resistance determinants using PCR. Strain diversity was assessed using biochemical and molecular criteria. E. coli was present in 19 subjects at levels ranging from 2.0×10(4) to 1.7×10(8) c.f.u. (g faeces)(-1). Strains resistant to one to six antibiotics were found at high levels (>30 %) in only ten individuals, but at significant levels (>0.5 %) in 14. Resistant isolates with the same phenotype from the same individual were indistinguishable, but more than one susceptible strain was sometimes found. Overall, individuals harboured one to four E. coli strains, although in 17 samples one strain was dominant (>70 % of isolates). Eighteen strains resistant to ampicillin, sulfamethoxazole, tetracycline and trimethoprim in 15 different combinations were observed. One resistant strain was carried by two unrelated individuals and a susceptible strain was shared by two cohabiting subjects. Two minority strains were derivatives of a more abundant resistant strain in the same sample, showing that continuous evolution is occurring in vivo. The trimethoprim-resistance genes dfrA1, dfrA5, dfrA7, dfrA12 or dfrA17 were in cassettes in a class 1 or class 2 integron. Ampicillin resistance was conferred by the bla(TEM) gene, sulfamethoxazole resistance by sul1, sul2 or sul3 and tetracycline resistance by tetA(A) or tetA(B). Chloramphenicol resistance (cmlA1 gene) was detected only once. Phylogenetic groups A and B2 were more common than B1 and D. Commensal E. coli of healthy humans represent an important reservoir for numerous antibiotic-resistance genes in many combinations. However, measuring the true extent of resistance carriage in commensal E. coli requires in-depth analysis.