Reducing overprescribing of antibiotics for suspected urinary tract infections in a health sciences campus student health service.

AIMS: Recommendations for the management of women with suspected uncomplicated lower urinary tract infections (UTIs) include presumptive antibiotics with or without obtaining a urine culture (UCx). However, with increasing antibiotic resistance, efforts to decrease antibiotic usage are vital. Therefore, the objective of this study was to determine if the presumptive treatment of women with suspected uncomplicated UTIs is contributing to unnecessary antibiotic usage. METHODS: We retrospectively reviewed all nonpregnant female patients presenting to our student health services clinic with UTI symptoms from December 2016 to May 2017 who had UCx sent. Clinical information, symptoms, office urine dip, and UCx results were reviewed. Patients with positive and negative UCx were compared. RESULTS: A total of 67 patients were included for analysis. Presenting symptoms included dysuria (59/60, 98%), frequency (41/45, 91%), and urgency (27/27, 100%). Office urine dip was performed on 33 of 67 (49%) patients. Dips were positive for leukocytes (88%), blood (79%), and nitrites (18%). All patients in the study were prescribed antibiotics, most commonly nitrofurantoin (82%). Culture results were negative in 29 of 67 (43%). There were no significant differences in duration of symptoms, presenting symptoms, or urine dip results between patients with a negative UCx and those with a positive UCx. CONCLUSIONS: In our study, we found a significant negative UCx rate in women with symptoms of uncomplicated UTI, representing a cohort of patients who were exposed to antibiotics unnecessarily. In addition, we found no difference in presenting symptoms or urine dip results to help distinguish patients with a positive UCx.

Condition-dependent transcriptome reveals high-level regulatory architecture in Bacillus subtilis.

Bacteria adapt to environmental stimuli by adjusting their transcriptomes in a complex manner, the full potential of which has yet to be established for any individual bacterial species. Here, we report the transcriptomes of Bacillus subtilis exposed to a wide range of environmental and nutritional conditions that the organism might encounter in nature. We comprehensively mapped transcription units (TUs) and grouped 2935 promoters into regulons controlled by various RNA polymerase sigma factors, accounting for ~66% of the observed variance in transcriptional activity. This global classification of promoters and detailed description of TUs revealed that a large proportion of the detected antisense RNAs arose from potentially spurious transcription initiation by alternative sigma factors and from imperfect control of transcription termination.

The transcription factor AlsR binds and regulates the promoter of the alsSD operon responsible for acetoin formation in Bacillus subtilis.

Bacillus subtilis forms acetoin under anaerobic fermentative growth conditions and as a product of the aerobic carbon overflow metabolism. Acetoin formation from pyruvate requires α-acetolactate synthase and acetolactate decarboxylase, both encoded by the alsSD operon. The alsR gene, encoding the LysR-type transcriptional regulator AlsR, was found to be essential for the in vivo expression of alsSD in response to anaerobic acetate accumulation, the addition of acetate, low pH, and the aerobic stationary phase. The expressions of the alsSD operon and the alsR regulatory gene were independent of other regulators of the anaerobic regulatory network, including ResDE, Fnr, and ArfM. A negative autoregulation of alsR was observed. In vitro transcription from the alsSD promoter using purified B. subtilis RNA polymerase required AlsR. DNA binding studies with purified recombinant AlsR in combination with promoter mutagenesis experiments identified a 19-bp high-affinity palindromic binding site (TAAT-N(11)-ATTA) at positions -76 to -58 (regulatory binding site [RBS]) and a low-affinity site (AT-N(11)-AT) at positions -41 to -27 (activator binding site [ABS]) upstream of the transcriptional start site of alsSD. The RBS and ABS were found to be essential for in vivo alsSD transcription. AlsR binding to both sites induced the formation of higher-order, transcription-competent complexes. The AlsR protein carrying the S100A substitution at the potential coinducer binding site still bound to the RBS and ABS. However, AlsR(S100A) failed to form the higher-order complex and to initiate in vivo and in vitro transcription. A model for AlsR promoter binding and transcriptional activation was deduced.