Research involving the cold shock gene cspA of the medically important bacterium Staphylococcus aureus is steadily increasing as the relationships between the activity of this gene at 37 °C and a spectrum of virulence factors (e.g., biofilm formation, capsule production) as well as stress-related genes (e.g., alkaline shock protein, asp-23 and the alternative sigma factor, sigB) are distinguished. Fundamental to each of these discoveries is defining the regulation of cspA and the production of its protein product CspA. In this paper, primer extension analysis was used to identify a transcriptional start point at 112 bp upstream of the initiation codon of the cspA coding sequence from S. aureus Newman RNA collected at 37 °C. Based on the location of the putative −10 and −35 sites as well as putative cold shock protein binding sites, a 192 bp sequence containing an 80 bp promoter + a 112 bp 5′ UTR was generated by polymerase chain reaction. The activity of this 192 bp sequence was confirmed in a pLL38 promoter::xylE reporter gene construct. In addition, Western blots were used to confirm the production of CspA at 37 °C and demonstrated that production of the protein was not constitutive but showed growth-dependent production with a significant increase at the 6 h time point. The results presented identify another regulatory region for the cold shock gene cspA of S. aureus and show growth-dependent activity of both this cspA regulatory sequence, presented as a 192 bp sequence of promoter + 5′ UTR and the production of the CspA protein at 37 °C. The presence of two active transcription start points, a −112 bp sequence defined in this work and a second previously defined at −514 bp upstream of the cspA initiation codon, suggests the possibility of interactions between these two regions in the regulation of cspA. The growth-dependent production of the cold shock protein CspA supports the availability of this protein to be a modulator of virulence and stress factor genes at 37 °C.

This retrospective study is intended to contribute to the ongoing investigations of antimicrobial resistance in companion animals by specifically examining the demographics, sex, rates of resistance, and multidrug resistance of bacteria isolated from urine samples of cats and dogs suspected of urinary tract infections (UTIs) in Arizona, USA, between 2018 and 2023. Escherichia coli was the most isolated bacterium with an overall frequency of 43.4%, followed by Enterococcus faecalis (11.5%), Proteus mirabilis (10.7%), Staphylococcus pseudintermedius (9.9%), Enterococcus faecium (6.9%), and Klebsiella pneumoniae (6.3%). Each year, culture-positive canine urine samples were more frequent than positive feline samples, with summer months producing the majority of suspected UTI samples for dogs and cats. Age played a role for culture-positive urine samples only in female dogs, with no association between age or sex and the number of positive feline samples. Feline Escherichia coli and Klebsiella pneumoniae isolates demonstrated more resistance to penicillins + beta-lactamase inhibitors than canines. The feline Enterococcus faecalis isolates also revealed significantly more resistance than canine isolates to penicillins + beta-lactamase inhibitors. In terms of multidrug resistance, a significant difference was found between the isolates of both Klebsiella pneumoniae and Proteus mirabilis and other bacterial species. These findings contribute to the relevant role antimicrobial surveillance plays in the prevention and control of UTI pathogens in companion animals. Because dogs and cats often are in close contact with their owners, they may be potential sources for human infection and a One Health concern.