Objective—To evaluate the efficacy of Lactobacillus
pentosus WE7, an equine-origin organism with potentially
beneficial in vitro properties, as a probiotic for
prevention of neonatal diarrhea in foals.
Design—Randomized controlled clinical trial.
Procedure—Foals were enrolled at 24 to 48 hours of
age and randomly assigned to treatment or control
groups. The treatment group received approximately
2 × 1011 CFU of freeze-dried L pentosus WE7 orally
once daily for 7 days, whereas the control group
received a placebo. Clinical monitoring was performed
for 14 days.
Results—Probiotic administration was significantly
associated with development of signs of depression,
anorexia, and colic and the need for veterinary examination
and treatment. Probiotic-treated foals also had
more days of diarrhea, compared with the control
group, although not significantly. In a multivariate
model, probiotic administration was significantly
associated with development of diarrhea and diarrhea
plus additional clinical abnormalities.
Conclusions and Clinical Relevance—Administration
of L pentosus WE7 did not prevent diarrhea; rather, it
was associated with development of diarrhea and,
most importantly, development of diarrhea plus additional
clinical abnormalities and the need for veterinary
intervention. The promising in vitro properties of
L pentosus WE7 were not evident in vivo. Results
raise concern about the variety of untested probiotic
products that are commercially available. Safety and
efficacy testing needs to be performed for all potential
equine probiotics. (J Am Vet Med Assoc 2005;226:
OBJECTIVE To evaluate adherence of methicillin-resistant Staphylococcus pseudintermedius (MRSP) to 5 suture materials commonly used in small animal surgery.
SAMPLE 10 epidemiologically unrelated MRSP isolates (obtained from dogs with clinical infections) that had strong biofilm-forming ability and 5 types of suture.
PROCEDURES The 5 types of suture evaluated were monofilament polyglecaprone 25, monofilament polydioxanone, triclosan-coated (TC)–monofilament polydioxanone, braided polyglactin 910, and barbed monofilament polydioxanone. Suture segments were incubated in standard suspensions of MRSP for 2 minutes. Segments were then placed in tryptone soy broth and incubated overnight. After incubation, segments were rinsed with PBS solution and sonicated to dislodge adherent bacteria. Resulting suspensions were used to create serial dilutions that were plated, incubated overnight, and counted the following day. Bacterial adherence to 1 segment of each suture type was assessed by use of scanning electron microscopy.
RESULTS There was significantly less adherence of MSRP to TC–monofilament polydioxanone than to polyglecaprone 25, polyglactin 910, barbed monofilament polydioxanone, and monofilament polydioxanone. There was significantly less adherence of MSRP to polyglecaprone than to polyglactin 910.
CONCLUSIONS AND CLINICAL RELEVANCE Barbed suture had a bacterial adherence profile comparable to that for monofilament suture. Adherence of MRSP was greatest for braided polyglactin 910. Use of TC–monofilament polydioxanone can be considered for patients that are at high risk of developing surgical site infections and for which a surgeon chooses a multifilament suture. (Am J Vet Res 2016;77:194–198)
OBJECTIVE To evaluate the impact of gentamicin, silver, or both additives in polymethylmethacrylate (PMMA) beads on methicillin-resistant Staphylococcus pseudintermedius (MRSP) biofilm formation in vitro.
SAMPLE 4 preparations of PMMA beads (formed with no additive [control], gentamicin, silver, and gentamicin and silver).
PROCEDURES Beads from each group were exposed to 10 MRSP isolates known to be strong biofilm formers. Following incubation, the beads were rinsed to remove planktonic bacteria, then sonicated to dislodge biofilm-associated bacteria. Resulting suspensions were serially diluted, plated on blood agar, and incubated overnight; CFUs were counted. Variance of mean CFU counts following log10 transformation was analyzed among PMMA groups.
RESULTS None of the PMMA additives tested completely inhibited MRSP biofilm formation. There was a significant effect of gentamicin and gentamicin plus silver on this variable, compared with controls, but not of silver alone. There was no difference between gentamicin and gentamicin plus silver. When only isolates not susceptible to gentamicin were evaluated, there were no significant differences among PMMA additive groups. Within gentamicin-susceptible isolates, there was an impact of gentamicin and gentamicin plus silver, but no impact of silver alone and no difference between gentamicin and gentamicin plus silver.
CONCLUSIONS AND CLINICAL RELEVANCE Gentamicin-impregnated PMMA was effective at reducing biofilm formation of gentamicin-susceptible MRSP isolates but had no effect on isolates not susceptible to gentamicin. Silver-impregnated PMMA had no effect on MRSP biofilm formation. Results suggested that gentamicin-impregnated PMMA may not be effective in vivo against MRSP isolates not susceptible to gentamicin. Antibacterial efficacy of silver should not be assumed without proper testing of the target bacteria and specific silver compound.
Case Description—Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from the tracheostomy tube of an 18-month-old castrated male Golden Retriever in the intensive care unit (ICU) of the Ontario Veterinary College. This prompted an investigation of MRSA colonization in other animals in the ICU.
Clinical Findings—On day 1 of the investigation, MRSA was isolated from nasal swabs obtained from 2 of 10 animals (2/7 dogs and 0/3 cats), including the index case. Subsequently, MRSA was isolated from 3 of 12 animals on day 9; 3 of 9 animals on day 13; and none of 14, 5, and 6 animals on day 20, 27, and 78, respectively. Overall, MRSA was isolated from 6 of 26 (23%) animals during the outbreak period (4/22 dogs and 2/4 cats). The apparent incidence of MRSA acquisition in the ICU from days 1 through 13 was 20% (5/25 animals). No clinical signs of MRSA infections developed. All isolates were indistinguishable from one another.
Treatment and Outcome—Infection-control measures including active surveillance of all animals in the ICU, barrier precautions, and hand hygiene were used to control the apparent outbreak.
Clinical Relevance—Methicillin-resistant S aureus is an emerging problem in veterinary medicine. Intensive care units may be at particular risk for periodic outbreaks of colonization and disease. The outbreak of this report highlights the potential for clinically inapparent transmission of MRSA within a facility; infection-control measures that might facilitate MRSA eradication should be considered in ICU settings.
Objective—To evaluate the prevalence of nasal colonization
with methicillin-resistant Staphylococcus
aureus (MRSA) in horses and horse personnel.
Design—Prospective prevalence study.
Sample Population—972 horses and 107 personnel
from equine farms in Ontario, Canada and New York
Procedure—Nasal swab specimens were collected
from horses and humans on farms with (targeted surveillance)
and without (nontargeted surveillance) a history
of MRSA colonization or infection in horses during
the preceding year. Selective culture for MRSA was
performed. Isolates were typed via pulsed-field gel
electrophoresis, and antibiograms were determined.
Results—MRSA was isolated from 46 of 972 (4.7%)
horses (0/581 via nontargeted surveillance and
46/391 [12%] via targeted surveillance). Similarly,
MRSA was isolated from 14 of 107 (13%) humans
(2/41 [5%] from nontargeted surveillance and 12/66
[18%] from targeted surveillance). All isolates were
subtypes of Canadian epidemic MRSA-5, an uncommon
strain in humans. All isolates were resistant to at
least 1 antimicrobial class in addition to β-lactams. On
all farms with colonized horses, at least 1 human was
colonized with an indistinguishable subtype. For horses,
residing on a farm that housed > 20 horses was
the only factor significantly associated with MRSA
colonization. For humans, regular contact with > 20
horses was the only identified risk factor.
Conclusions and Clinical Relevance—Results confirm
a reservoir of colonized horses on a variety of farms in
Ontario and New York and provide evidence that 1
MRSA strain is predominantly involved in MRSA colonization
in horses and humans that work with horses.
(J Am Vet Med Assoc 2005;226:580–583)
Objective—To evaluate the association between preoperative carriage of methicillin-resistant Staphylococcus pseudintermedius (MRSP) and the development of surgical site infections (SSIs) following tibial plateau leveling osteotomy (TPLO) in dogs.
Design—Prospective multicenter study.
Procedures—At 7 veterinary hospitals, swab specimens were obtained from the pharynx, nares, rectum, and skin of dogs admitted for TPLO. Specimens were submitted for culture of MRSP. For each dog, information regarding preoperative and postoperative antimicrobial administration, comorbidities, contact with other dogs, and whether the dog developed an SSI was obtained. Univariable and multivariable analyses were performed to identify variables associated with preoperative and postoperative MRSP colonization and the development of an SSI.
Results—Of the 549 study dogs, 24 (4.4%) were identified as MRSP carriers before TPLO and 37 (6.7%) developed an SSI after TPLO. Bacteriologic culture was performed on specimens obtained from 32 of the 37 SSIs, and MRSP was isolated from 11 (34%). Carriers of MRSP (OR, 6.72; 95% confidence interval [CI], 2.12 to 21.4) and Bulldogs (OR, 11.1; 95% CI, 2.07 to 59.3) were at risk for development of an SSI after TPLO, whereas postoperative administration of antimicrobials (OR, 0.36; 95% CI, 0.15 to 0.91) appeared to protect against development of an SSI.
Conclusions and Clinical Relevance—Results indicated that carriage of MRSP were a risk factor for development of an SSI after TPLO and measures to rapidly identify and treat MRSP carriers are warranted. Postoperative administration of antimicrobials protected against development of an SSI after TPLO.