Objective—To evaluate the effects of various concentrations of l-lysine on in vitro replication of feline herpesvirus 1 (FHV-1).
Sample—Cultures of Crandell-Rees feline kidney (CRFK) cells.
Procedures—CRFK cells were inoculated with FHV-1 and maintained in media with 20 combinations of l-arginine and l-lysine concentrations. Changes in cell viability were monitored by continuous measurement of electrical impedance of cultured cells and by observation of viral cytopathic effects. Viral load was determined by use of quantitative PCR assay in supernatants obtained from infected cultures at specified time points.
Results—Increases in l-lysine concentration had no effect on the kinetics of cell death in FHV-1-infected cultures. There was also no significant effect (r2 < 0.1) on viral DNA load for l-arginine concentrations ≥ 12 μg/mL There was a significant effect of increases in l-lysine concentration on viral DNA load in media supplemented with 6 μg of l-arginine/mL (mean ± SD slope, −4,641 ± 1,626 units; adjusted r2 = 0.45). However, the difference between the lowest (1 × 106.28 copies/μL) and highest (1 × 106.86 copies/μL) FHV-1 DNA load in these media was < 1 logarithm.
Conclusions and Clinical Relevance—The difference in FHV-1 DNA load was unlikely to be biologically important. Various l-lysine concentrations did not inhibit in vitro replication of FHV-1 at l-arginine concentrations sufficient to maintain cell growth. This conclusion was consistent with results of other studies in which investigators have not detected a consistently beneficial effect when l-lysine is administered to FHV-1-infected cats.
Objective—To evaluate effectiveness of 4% peroxymonosulfate
disinfectant applied as a mist to surfaces
in a large animal hospital as measured by recovery of
Staphylococcus aureus and Salmonella enterica
Sample Population—Polyester transparencies inoculated
Procedure—Polyester transparencies were inoculated
with S aureus or S Typhimurium and placed in various
locations in the hospital. After mist application of the
peroxygen disinfectant, viable bacterial numbers were
quantified and compared with growth from control
transparencies to assess reduction in bacterial count.
Results—When applied as a mist directed at environmental
surfaces contaminated with a geometric
mean of 4.03 × 107 CFUs of S aureus (95% confidence
interval [CI], 3.95 × 107 to 4.11 × 107) or 6.17 ×
106 CFUs of S Typhimurium (95% CI, 5.55 × 106 to
6.86 × 106), 4% peroxymonosulfate reduced the geometric
mean number of viable S aureus by 3.04 × 107
CFUs (95% CI, 8.6 × 105 to 1.7 × 106) and S
Typhimurium by 3.97 × 106 CFUs (95% CI, 8.6 × 105 to
3.5 × 106).
Conclusions and Clinical Relevance—Environmental
disinfection with directed mist application of a 4% peroxymonosulfate
solution was successful in reducing
counts of bacterial CFUs by > 99.9999%. Directed
mist application with this peroxygen disinfectant as
evaluated in this study appeared to be an effective and
efficient means of environmental disinfection in a large
animal veterinary hospital and would be less disruptive
than more traditional approaches to intensive environmental
cleaning and disinfection. (J Am Vet Med
Objective—To evaluate the effects of footwear hygiene protocols on bacterial contamination of floor surfaces in an equine hospital.
Procedures—Footwear hygiene protocols evaluated included use of rubber overboots with footbaths and footmats containing a quaternary ammonium disinfectant, rubber overboots with footbaths and footmats containing a peroxygen disinfectant, and no restrictions on footwear type but mandatory use of footbaths and footmats containing a peroxygen disinfectant. Nonspecific aerobic bacterial counts were determined via 2 procedures for sample collection and bacterial enumeration (contact plates vs swabbing combined with use of spread plates), and the effects of each footwear hygiene protocol were compared.
Results—There were no consistent findings suggesting that any of the protocols were associated with differences in numbers of bacteria recovered from floor surfaces. Although there were detectable differences in numbers of bacteria recovered in association with different footwear hygiene protocols, differences in least square mean bacterial counts did not appear to be clinically relevant (ie, were < 1 log10).
Conclusions and Clinical Relevance—Although cleaning and disinfection of footwear are important aids in reducing the risk of nosocomial transmission of infectious agents in veterinary hospitals, the numbers of aerobic bacteria recovered from floor surfaces were not affected by use of rubber overboots or the types of disinfectant used in this study. Further study is warranted to evaluate the usefulness of footwear hygiene practices relative to their efficacy for reducing transmission of specific pathogens or decreasing nosocomial disease risk.