TetR-family transcription factors in Gram-negative bacteria: conservation, variation and implications for efflux-mediated antimicrobial resistance.

BACKGROUND: TetR-family transcriptional regulators (TFTRs) are DNA binding factors that regulate gene expression in bacteria. Well-studied TFTRs, such as AcrR, which regulates efflux pump expression, are usually encoded alongside target operons. Recently, it has emerged that there are many TFTRs which act as global multi-target regulators. Our classical view of TFTRs as simple, single-target regulators therefore needs to be reconsidered. As some TFTRs regulate essential processes (e.g. metabolism) or processes which are important determinants of resistance and virulence (e.g. biofilm formation and efflux gene expression) and as TFTRs are present throughout pathogenic bacteria, they may be good drug discovery targets for tackling antimicrobial resistant infections. However, the prevalence and conservation of individual TFTR genes in Gram-negative species, has to our knowledge, not yet been studied. RESULTS: Here, a wide-scale search for TFTRs in available proteomes of clinically relevant pathogens Salmonella and Escherichia species was performed and these regulators further characterised. The majority of identified TFTRs are involved in efflux regulation in both Escherichia and Salmonella. The percentage variance in TFTR genes of these genera was found to be higher in those regulating genes involved in efflux, bleach survival or biofilm formation than those regulating more constrained processes. Some TFTRs were found to be present in all strains and species of these two genera, whereas others (i.e. TetR) are only present in some strains and some (i.e. RamR) are genera-specific. Two further pathogens on the WHO priority pathogen list (K. pneumoniae and P. aeruginosa) were then searched for the presence of the TFTRs conserved in Escherichia and Salmonella. CONCLUSIONS: Through bioinformatics and literature analyses, we present that TFTRs are a varied and heterogeneous family of proteins required for the regulation of numerous important processes, with consequences to antimicrobial resistance and virulence, and that the roles and responses of these proteins are frequently underestimated.

The effects of a four week jump-training program on frontal plane projection angle in female gymnasts.

OBJECTIVES: To investigate the effects of a four week jump training program on frontal plane projection angle (FPPA) in young female gymnasts. DESIGN: Intervention study, consisting of a four week jump training program performed for 15 min as part of a warm-up, three days per week for four weeks. SETTING: Gymnastics training center. PARTICIPANTS: Fourteen youth female gymnasts (age: 13.5 ± 2.14 years, height: 1.54 ± 0.11 m, body mass: 46.23 ± 7.68 kg). MAIN OUTCOME MEASURES: Change in FPPA during a 30 cm drop landing and tuck back somersault. RESULTS: Large and significant decreases (p < 0.001) in FPPA of 6.8° (39%) and 8.4° (37%) during the drop landing and tuck back somersault, respectively. CONCLUSION: The jump training program was successful in improving FPPA in female gymnasts and is advised to be implemented into the warm-ups and training programs of competitive female gymnasts to improve FPPA and therefore reduce the risk factors associated with knee injuries.

Pocket-sized point-of-care cardiac ultrasound devices : Role in the emergency department.

BACKGROUND: Acute breathlessness accounts for 8% of accident and emergency attendances. Point-of-care cardiac ultrasound (US) effectively reduces time to diagnosis. Fast and practical information via pocket-sized cardiac US devices may better the diagnosis in this complex patient group. METHODS: We prospectively enrolled 40 consecutive patients presenting with shortness of breath at the emergency department (ED). Divided into two groups were all adult patients over 18 with acute breathing difficulties (triage category 1-3): 21 patients received a short focused cardiac US scan using a pocket-sized Vscan and 19 patients received no scan. Data were obtained regarding the time taken for diagnosis and treatment, patient length of stay, inpatient mortality and 30-day mortality. RESULTS: In the scanned group 33% of patients had significantly abnormal Vscan results that had the potential to aid diagnosis and guide management. The difference of 20 min between the means of the time to diagnosis between the groups was not significant. DISCUSSION: The individual knowledge of UK emergency physicians regarding basic echocardiography varies greatly. An intuitive approach following a brief tutorial on pocket-size echocardiography was shown to improve diagnostic accuracy in addition to history taking and physical examination by medical students and junior doctors with no previous exposure to echocardiography. Increasing evidence shows the feasibility and benefit of FOCUS echo in the ED and the pocket-sized devices could play a large role. CONCLUSION: The Vscan is a practical, portable device that provides rapid diagnostic information. One third of patients had significant findings on the scans to possibly aid diagnosis and prevent misdiagnosis. This has the potential to reduce time to diagnosis in the ED.

TARGETed surveillance: susceptibility of Streptococcus pneumoniae isolated from community-acquired respiratory tract infections in 2003 to fluoroquinolones and other agents.

We assessed antibiotic resistance in Streptococcus pneumoniae collected worldwide in 2003. Resistance to clarithromycin was the highest overall (34.1%) followed by penicillin G (22.1%). Patient age and/or country of origin had the greatest effect on susceptibility. Resistance was highest in children<6 years of age and in patients from South Africa or France. Resistance to penicillin or amoxicillin/clavulanic acid decreased in adults and was low in Germany. Fluoroquinolone resistance was very low overall, but 3.0% levofloxacin resistance (2.6% gatifloxacin and 0.4% moxifloxacin) was observed in Italy. Interestingly, many isolates with minimum inhibitory concentrations (MICs) at the top of the fluoroquinolone susceptibility breakpoints possessed single quinolone resistance-determining region (QRDR) mutations. Care should be taken when treating fluoroquinolone-susceptible isolates with a higher MIC, which are likely to harbour QRDR mutations and may become fully resistant and cause treatment failure. We concur with the conclusions of other recent studies that suggest fluoroquinolone breakpoints should be lowered to ensure these isolates are categorised as resistant. Fluoroquinolones would still remain an important alternative treatment for respiratory tract infections (albeit for adults only), with moxifloxacin being the most potent fluoroquinolone tested in this study.

Reporting cervical intra-epithelial neoplasia (CIN): intra- and interpathologist variation and factors associated with disagreement.

Eight histopathologists, based at different hospitals, who had previously examined 100 consecutive colposcopic cervical biopsies were circulated with the results of the initial study. The slides were then 'reblinded' and re-examined by the pathologists who, as before, assigned them into one of six diagnostic categories. The degree of interpathologist agreement for the seven observers who returned usable responses was characterized by kappa statistics and compared to the corresponding figures for the same observers from the previous study. Although some of the observers showed significant alterations in their diagnostic practices there was persistent poor agreement for CIN 1 and 2, mediocre agreement for CIN 3 and excellent agreement for invasive carcinoma. Intra-observer agreement was consistently better than inter-observer agreement for each of the diagnostic categories. Significant differences were found among observers in the degree of intra-observer variability. The 20 cases in which there was most disagreement were re-examined by one of the authors who compared these with 20 biopsies which caused little disagreement. Disagreement was considered to be associated with florid papilloma-virus changes, basal cell hyperplasia and severe inflammation in varying combinations. On the basis of these findings we suggest changes in the terminology of CIN lesions.

Observer variation in histopathological diagnosis and grading of cervical intraepithelial neoplasia.

To assess the variability among histopathologists in diagnosing and grading cervical intraepithelial neoplasia eight experienced histopathologists based at different hospitals examined the same set of 100 consecutive colposcopic cervical biopsy specimens and assigned them into one of six diagnostic categories. These were normal squamous epithelium, non-neoplastic squamous proliferations, cervical intraepithelial neoplasia grades I, II, and III, and other. The histopathologists were given currently accepted criteria for diagnosing and grading cervical intraepithelial neoplasia and asked to mark their degree of confidence about their decision on a visual linear analogue scale provided. The degree of agreement between the histopathologists was characterised by kappa statistics, which showed an overall poor agreement (unweighted kappa 0.358). Agreement between observers was excellent for invasive lesions, moderately good for cervical intraepithelial neoplasia grade III, and poor for cervical intraepithelial neoplasia grades I and II (unweighted kappa 0.832, 0.496, 0.172, and 0.175, respectively); the kappa value for all grades of cervical intraepithelial neoplasia taken together was 0.660. The most important source of disagreement lay in the distinction of reactive squamous proliferations from cervical intraepithelial neoplasia grade I. The histopathologists were confident in diagnosing cervical intraepithelial neoplasia grade III and invasive carcinoma (other) but not as confident in diagnosing cervical intraepithelial neoplasia grades I and II and glandular atypia (other). Experienced histopathologists show considerable interobserver variability in grading cervical intraepithelial neoplasia and more importantly in distinguishing between reactive squamous proliferations and cervical intraepithelial neoplasia grade I. It is suggested that the three grade division of cervical intraepithelial neoplasia should be abandoned and a borderline category introduced that entails follow up without treatment.