Prolonged cefazolin course for treatment of methicillin susceptible staphylococcus species infections and the impact on the emergence of multidrug-resistant bacteria during cloxacillin shortage.

OBJECTIVES: To describe the efficacy and safety of prolonged cefazolin course for Staphylococcus infection and the emergence of multidrug-resistant bacteria carriage after treatment. METHODS: Monocentric retrospective cohort study of patients hospitalized for blood stream infections (BSI) and osteoarticular infections (OAI) by methicillin susceptible staphylococcal species treated with cefazolin from January 2015 to July 2017. Rectal and nasal swabs were performed at cefazolin initiation and end of treatment to detect respectively methicillin resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase (ESBL) producing bacteria. RESULTS: Fifty-eight patients were included, 41 had a bacteremia including 22 endocarditis and 22 OAI. Mean duration of treatment was 21.5 days at a mean daily dose of 6.5g/d. Fifty-five (94.5%) received combination therapy. Fifty-two (89.7%) of patients achieved bacteriological cure. Four patients were ESBL carriers at inclusion. No additional ESBL or MRSA were detected by end of treatment. CONCLUSION: Cefazolin appears as an effective and safe treatment for BSI or osteoarticular infection and does not appear to select MRSA or ESBL.

Rifampin combination therapy in staphylococcal prosthetic joint infections: a randomized controlled trial.

BACKGROUND: The evidence supporting rifampin combination therapy in prosthetic joint infections (PJI) is limited due to the lack of controlled studies. The aim of this study is to evaluate the effect of adding rifampin to conventional antimicrobial therapy in early staphylococcal PJIs treated with debridement and retention of the implant (DAIR). METHODS: In this multicenter randomized controlled trial, 99 patients with PJI after hip and knee arthroplasties were enrolled. They were randomly assigned to receive rifampin or not in addition to standard antimicrobial treatment with cloxacillin or vancomycin in case of methicillin resistance. The primary endpoint was no signs of infection after 2 years of follow-up. RESULTS: Forty-eight patients were included in the final analyses. There were no differences in patient characteristics or comorbidities between the two groups. There was no significant difference in remission rate between the rifampin combination group (17 of 23 (74%)) and the monotherapy group (18 of 25 (72%), relative risk 1.03, 95% confidence interval 0.73 to 1.45, p = 0.88). CONCLUSION: This trial has not proven a statistically significant advantage by adding rifampin to standard antibiotic treatment in acute staphylococcal PJIs. TRIAL REGISTRATION: The Regional Ethics Committee and the Norwegian Medicines Agency approved the study (EudraCT 2005-005494-29), and the study was registered at ClinicalTrials.gov at Jan 18, 2007 ( NCT00423982 ).

Antibiotic dry buffalo therapy: effect of intramammary administration of benzathine cloxacillin against Staphylococcus aureus mastitis in dairy water buffalo.

BACKGROUND: Mastitis is one of the most costly diseases in Mediterranean buffalo (MB). At present, just a few specific antibiotics registered for this dairy specie have been synthetized. Efficacy of an antibiotic dry buffalo therapy (aDBT) against Staphylococcus aureus (S. aureus) mastitis, based on intra-quarter administration of 600 mg of benzathine cloxacillin, have been evaluated for the first time. Eighty MB's quarters received a drying-off therapy (aDBT-group) and 80 were left untreated (no-aDBT-group). They were sampled at drying-off (pre-treatment) and at the resumption of milking [< 10 days in milk (DIM)]. Fresh calver mastitis rate, dry period new mastitis rate, dry period cure rate, and persistent mastitis rate were calculated for clinical monitoring. Overall proportion of positive quarters/animals, quarters affected by mastitis or intramammary infections (IMI), effects on somatic cell count (SCC) and milk yield were also assessed. RESULTS: An inter-group difference (aDBT vs. no-aDBT) was recorded for all the indexes considered. An intra-group (drying-off vs. < 10 DIM) difference was detected in aDBT-group regarding the proportion of positive-cultured quarters and animals. Concerning the latter, an inter-groups difference was also recorded at second sampling. No clinical mastitis due to the S. aureus was observed. Regarding the subclinical ones, a higher intra-group difference was observed in aDBT than no-aDBT group, while an inter-group difference was recorded at second sampling. No protective effect was observed against IMI. SCC showed an inter-group difference at second sampling, while none difference was instead detected for milk yield. CONCLUSIONS: The effects against S. aureus mastitis of benzathine cloxacillin administration at drying-off were assessed for the first time in MB. Its use shows encouraging results in reducing the proportion of mastitis and positive animals at the resumption of the lactation.

Salmonella enterica serovar Paratyphi A isolated from a hard-to-heal diabetic ulcer: a case report.

Chronically infected diabetic wounds have a polymicrobial aetiology. However, Salmonella Paratyphi A is a very rare cause of wound infection. A 76-year-old female patient with type II diabetes presented with a wound on the left leg of two months' duration. The wound was painful, erythematous and a thick, foul-smelling discharge was present. There was a history of delayed wound healing. Salmonella Paratyphi A and Pseudomonas aeruginosa were isolated from the wound tissue. The patient was treated with cefuroxime and cloxacillin empirically and following the antibiotic susceptibility testing (ABST) report, ciprofloxacin was given for 10 days. The wound was treated with multiple debridements and topical antiseptic. On follow-up, the patient remained afebrile with subsiding discharge from the ulcer. This is the first reported case of Salmonella Paratyphi A from an infected diabetic ulcer in Sri Lanka and it serves to further define the spectrum of illnesses caused by this uncommon pathogen.

Intravenously administered cloxacillin-induced neutropenia with eosinophilia in a patient with infective endocarditis: a case report.

BACKGROUND: Bacteremia following Staphylococcus aureus is a serious clinical condition which is often associated with distant metastatic infections. One of the most dreaded complications of Staphylococcus aureus bacteremia is infective endocarditis. Cloxacillin is a common antibiotic prescribed for suspected staphylococcal infections and confirmed methicillin-sensitive Staphylococcus aureus infections. Prolonged use of cloxacillin may lead to neutropenia. CASE PRESENTATION: A 38-year-old Sinhalese man presented to Teaching Hospital Kurunegala, Sri Lanka, complaining of a 3-week history of fever; he was found to have a pansystolic murmur over the apex of his heart. He had leukocytosis with predominant neutrocytosis. His C-reactive protein was 231 mg/l and erythrocyte sedimentation rate was 100 mm/first hour. Transthoracic two-dimensional echocardiography revealed prolapsed mitral valve with 7 × 13 mm vegetation over the posterior mitral valve. On the following day, three blood cultures became positive and were subsequently identified as Staphylococcus aureus. Intravenously administered cloxacillin 3 g 6 hourly was started. Following day 24 of intravenously administered cloxacillin, our patient developed high spike fever. His total white blood cells were: 990/mm3 with 34% neutrophils and 22% eosinophils. His hemoglobin concentration was 9.5 g/dL and platelet count remained normal (202 × 106/mm3). His C-reactive protein was 78 mg/l, erythrocyte sedimentation rate was 95 mm/first hour, and he was otherwise comfortable, showing no signs of sepsis beside the high grade fever. His serum was negative for filarial and Toxoplasma antibodies while stool was negative for oocytes and amoebic cysts. Further, his serum was negative for dengue virus, Epstein-Barr virus, cytomegalovirus, and hepatitis B antibodies. He was clinically well on day 6 after stopping cloxacillin with 44% neutrophils and 18% eosinophils. His C-reactive protein and erythrocyte sedimentation rate became normal, and there was no further plan for cardiothoracic intervention or administration of antimicrobials. He was discharged from hospital and remained well 6 months later. CONCLUSION: This case report signifies the potential fatal adverse effect of cloxacillin in methicillin-sensitive Staphylococcus aureus infections. Leukopenia is associated with prolonged use of high doses of cloxacillin. In addition to transthoracic two-dimensional echocardiography and inflammatory markers, sequential white blood cells and differential counts would help clinicians to assess the prognosis of patients with infective endocarditis.

Successful desensitization to cloxacillin in a patient with sepsis, with infective endocarditis and clinical suspicion of hypersensitivity to penicillins, a case report.

WHAT IS KNOWN AND OBJECTIVE: Beta-lactam antibiotic (BLA) therapy is frequently needed to treat infective endocarditis (IE). Hypersensitive reactions to BLA restrict BLA therapy in allergic patients. In the current case, we aim to describe the utility of desensitization (DS) in this context. Although the evidence is limited, DS is recommended. CASE DESCRIPTION: This case report deals with a 79-year-old woman with a clinical suspicion of allergy to BLA and a methicillin-sensitive Staphylococcus aureus (MSSA) IE. A cloxacillin DS protocol was developed to enable treatment with cloxacillin. WHAT IS NEW AND CONCLUSION: Alternative antibiotic treatments may be less effective or not available in MSSA IE. In this case report, DS allowed optimal cloxacillin treatment.

Daptomycin versus placebo as an adjunct to beta-lactam therapy in the treatment of Staphylococcus aureus bacteremia: study protocol for a randomized controlled trial.

BACKGROUND: Staphylococcus aureus bacteremia is associated with significant morbidity and mortality. To treat this infection, the current standard of care includes intravenous anti-staphylococcal beta-lactam antibiotics and obtaining adequate source control. Combination therapy with an aminoglycoside or rifampin, despite early promise, can no longer be routinely recommended due to an absence of proven benefit and risk of harm. Daptomycin is a rapidly acting bactericidal antibiotic that is approved for the treatment of Staphylococcus aureus bacteremia as monotherapy but has not been shown to be superior to the current standard of care. As demonstrated in vitro, the addition of daptomycin to beta-lactam therapy may result in enhanced anti-staphylococcal activity. Our objective is to assess the efficacy and safety of prescribing the combination of daptomycin with cefazolin or cloxacillin for the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia in adults. We hypothesize that adjunctive therapy with daptomycin will reduce the duration of bacteremia in this population. METHODS: The DASH-RCT trial is a randomized, double blind, placebo-controlled trial designed per the Standard Protocol Items: Recommendation for Interventional Trials (SPIRIT) and Consolidated Standards of Reporting Trials (CONSORT) guidelines. We recruit adults with confirmed MSSA bacteremia, at the McGill University Health Center. Patients are eligible if they are 18 years or older, can receive cefazolin or cloxacillin monotherapy, and are enrolled within 72 h of the first blood culture being drawn. Exclusion criteria include anaphylaxis to study drugs, having polymicrobial bacteremia, anticipated hospital admission for < 5 days, and healthcare team refusal. While receiving standard of care, study patients are randomized to a 5-day course of adjunctive daptomycin or placebo. The trial began in December 2016 and is expected to end in December 2018, after recruiting an estimated 102 patients. DISCUSSION: The DASH-RCT will compare the use of daptomycin as an adjunct to an anti-staphylococcal beta-lactam versus placebo in the treatment of MSSA bacteremia. We believe that a short course of dual therapy will result in earlier eradication of bacteremia and that subsequent research could evaluate effects on metastatic infection, relapse, and/or mortality. Ongoing issues in the trial include a delay between presentation of infection, enrollment in the trial, and the potential for unrecognized deep foci of infection at diagnosis. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02972983 . Registered on 25 November 2016. Trial protocol: http://individual.utoronto.ca/leet/dash/dashprotocol.pdf.

Gentamicin may have no effect on mortality of staphylococcal prosthetic valve endocarditis.

PURPOSE: To analyze the influence of adding gentamicin to a regimen consisting of ß-lactam or vancomycin plus rifampicin on survival in patients suffering from Staphylococcal prosthetic valve endocarditis (SPVE). METHODS: From January 2008 to September 2016, 334 patients with definite SPVE were attended in the participating hospitals. Ninety-four patients (28.1%) received treatment based on ß-lactam or vancomycin plus rifampicin and were included in the study. Variables were analyzed which related to patient survival during admission, including having received treatment with gentamicin. RESULTS: Seventy-seven (81.9%) were treated with cloxacillin (or vancomycin) plus rifampicin plus gentamicin, and 17 patients (18.1%) received the same regimen without gentamicin. The causative microorganism was Staphylococcus aureus in 40 cases (42.6%) and coagulase-negative staphylococci in 54 cases (57.4%). Overall, 40 patients (42.6%) died during hospital admission, 33 patients (42.9%) in the group receiving gentamicin and 7 patients in the group that did not (41.2%, P = 0.899). Worsening renal function was observed in 42 patients (54.5%) who received gentamicin and in 9 patients (52.9%) who did not (p = 0.904). Heart failure as a complication of endocarditis (OR: 4.58; CI 95%: 1.84-11.42) and not performing surgery when indicated (OR: 2.68; CI 95%: 1.03-6.94) increased mortality. Gentamicin administration remained unrelated to mortality (OR: 1.001; CI 95%: 0.29-3.38) in the multivariable analysis. CONCLUSIONS: The addition of gentamicin to a regimen containing vancomycin or cloxacillin plus rifampicin in SPVE was not associated to better outcome.

Chitosan and cloxacillin combination improve antibiotic efficacy against different lifestyle of coagulase-negative Staphylococcus isolates from chronic bovine mastitis.

Bovine mastitis affects the health of dairy cows and the profitability of herds worldwide. Coagulase-negative staphylococci (CNS) are the most frequently isolated pathogens in bovine intramammary infection. Based on the wide range of antimicrobial, mucoadhesive and immunostimulant properties demonstrated by chitosan, we have evaluated therapy efficiency of chitosan incorporation to cloxacillin antibiotic as well as its effect against different bacterial lifestyles of seven CNS isolates from chronic intramammary infections. The therapeutic effects of combinations were evaluated on planktonic cultures, bacterial biofilms and intracellular growth in mammary epithelial cells. We found that biofilms and intracellular growth forms offered a strong protection against antibiotic therapy. On the other hand, we found that chitosan addition to cloxacillin efficiently reduced the antibiotic concentration necessary for bacterial killing in different lifestyle. Remarkably, the combined treatment was not only able to inhibit bacterial biofilm establishment and increase preformed biofilm eradication, but it also reduced intracellular bacterial viability while it increased IL-6 secretion by infected epithelial cells. These findings provide a new approach to prophylactic drying therapy that could help to improve conventional antimicrobial treatment against different forms of bacterial growth in an efficient, safer and greener manner reducing multiresistant bacteria generation and spread.

A comparison of the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts after calving in cows also given internal teat sealants.

AIM: To compare, in cows treated with an internal teat sealant, the effect of short-acting and long-acting cloxacillin-based dry-cow therapy on somatic cell counts (SCC) after calving. METHODS: Cows from a spring-calving, pasture-based dairy farm in the Manawatu-Whanganui region of New Zealand were randomly allocated to receive either a short-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=291) or a long-acting cloxacillin and ampicillin dry-cow therapy and internal teat sealant (n=288) at the end of lactation. Cows were managed on-farm with routine husbandry procedures through the dry period and following calving. A multivariable logistic regression model was used to determine the association between length of action of dry-cow therapy and the proportion of cows with a SCC >150,000 cells/mL at the first herd test after calving. RESULTS: Age of cow, mean SCC for the preceding season and interval from calving to the first post-calving herd test were all associated with the proportion of cows with an individual SCC >150,000 cells/mL at the first herd test (p<0.001) Treatment with the short-acting dry-cow therapy was not associated with decreased odds of cows having a SCC >150,000 cells/mL at the first herd test compared with treatment with long-acting dry-cow therapy (OR=0.724; 95% CI=0.40-1.30). CONCLUSIONS AND CLINICAL RELEVANCE: In this herd, which routinely used internal teat sealants, the use of short-acting cloxacillin-based dry-cow therapy did not result in an increased proportion of cows with elevated SSC post-calving. This was a single farm, single year study but indicates that in this herd, changing from a long-acting to a short-acting antimicrobial may have no impact on the prevalence of subclinical mastitis.

Impact of intramammary tilmicosin infusion as a dry cow therapy.

Three hundred subclinically infected quarters of 259 Holstein cows infected with gram-positive bacteria were selected via quota sampling based on the California Mastitis Test (CMT) result and were divided randomly and equally into treatment and test groups. Quarters of test group (n = 150 in 128 cows) were treated with an intramammary infusion of tilmicosin, and quarters of the control group (n = 150 in 131 cows) were treated with cloxacillin as a traditional intramammary infusion of dry cow (DC) ointment. Cows with more than one infected quarter were randomly assigned to the same group, and adjacent quarters were treated the same. The milk samples of all quarters were obtained, and bacterial cultures and somatic cell count (SCC) were tested before dry cow therapy (DCT) (50 ± 15 days before parturition), and finally on day 2 of the next lactation. Results have shown that total bacteriological cure rates on day 2 of the next lactation were 45% and 78%, (p = .01), new infection rates were 43.3% and 56.6%, and SCC was (6.732 × 105  ± 3.124 × 105 ) and (5.025 × 105  ± 2.935 × 105 ), (p > .05) in test and control groups, respectively. Tilmicosin had less effect on reducing IMI due to Corynebacterium bovis, and had no effect on Streptococcus agalactiae, but had a potent effect against Staphylococcus aureus. It was concluded that tilmicosin alone should not be infused as an alternative to conventional dry cow therapy. However, it had a significant effect against S. aureus, and the potential of tilmicosin to treat S. aureus IMI should be confirmed in further studies.

Role of outpatient parenteral antibiotic therapy in the treatment of community acquired skin and soft tissue infections in Singapore.

BACKGROUND: Treatment of community acquired skin and soft tissue infections (SSTIs) is a common indication for outpatient parenteral antibiotic therapy (OPAT) in USA, UK and Australasia, however data from Asia are lacking. OPAT is well established within the Singapore healthcare since 2002, however, systematic use of OPAT for the treatment of SSTIs remains infrequent. In this report, we describe the treatment and outcome of patients with SSTIs referred directly from Emergency Department (ED) to OPAT for continuation of intravenous (IV) antibiotics in Singapore, thus avoiding potential hospital admission. METHOD: This is a single center university hospital retrospective study of patients with SSTIs presenting to ED who were assessed to require IV antibiotics and accepted to the OPAT clinic for continuation of IV treatment. Exclusion criteria were: haemodynamic instability, uncontrolled or serious underlying co-morbidities, necessity for inpatient surgical drainage, facial cellulitis and cephalosporin allergy. Patients returned daily to the hospital's OPAT clinic for administration of IV antibiotics and review, then switched to oral antibiotics on improvement. RESULTS: From 7 February 2012 to 31 July 2015, 120 patients with SSTIs were treated in OPAT. Median age was 56 years and 63% were male. Lower limbs were affected in 91%. Diabetes was present in 20%. Sixty-seven (56%) had been treated with oral antibiotics for a median duration of 3 days prior to OPAT treatment. Common symptoms were erythema (100%), swelling (96%), pain (88%) and fever (55%). Antibiotics administered were IV cefazolin with oral probenecid (71%) or IV ceftriaxone (29%) for median 3 days then oral cloxacillin (85%) for median 7 days. Clinical improvement occurred in 90%. Twelve patients (10%) were hospitalized for worsening cellulitis, with 4 patients requiring surgical drainage of abscess. Microbiological cultures from 2 patients with drained abscess grew methicillin sensitive Staphylococcus aureus (MSSA) and Klebsiella pneumoniae, both of which were susceptible to cefazolin and ceftriaxone. Hospital bed days saved was 318 days. CONCLUSION: OPAT treatment of community acquired SSTIs in a selected patient population has good outcomes in Singapore. Treatment with IV cefazolin or IV ceftriaxone was successful in the majority with low hospital readmission rate.

Nail Scabies: An Unusual Presentation Often Overlooked and Mistreated.

Nail scabies is an interesting clinical presentation of scabies. Although it is usually found concomitant with characteristic dermatologic manifestations, it may present as an isolated finding in the immunocompromised host. This condition is commonly mistaken with other diseases such as nail dystrophy, nail psoriasis and onychomycosis. We report two cases of unusual nail presentations that provide clues to diagnosis. Also, literature on unusual nail and dermatologic presentations was reviewed to recognize dermatologist consideration for appropriate treatment options.

Demonstration of non-inferiority of a novel combination intramammary antimicrobial in the treatment of clinical mastitis.

AIM: To test the non-inferiority of a novel combination intramammary product containing penicillin and cloxacillin to a reference intramammary product containing oxytetracycline, oleandomycin, neomycin and prednisolone with regard to bacteriological cure and clinical cure. METHODS: Clinical cases of mastitis were sourced from 30 spring-calving dairy farms in the Southland region of New Zealand. Affected quarters were infused three times at 24 hourly intervals with either the novel combination product containing 1 g penicillin and 200 mg cloxacillin, or a reference product containing 200 mg oxytetracycline, 100 mg oleandomycin, 100 mg neomycin and 5 mg prednisolone. Cows were enrolled when a farmer detected a case of clinical mastitis. Milk samples were collected for microbiological culture immediately before treatment (Day 0) and on Days 9, 16 and 23. Bacteriological cure was compared for 187 and 178 quarters treated with the reference and novel product, respectively, and clinical cure was compared for 235 and 223 quarters, respectively. Non-inferiority was assessed by calculating the difference in cure rates between the two products and constructing a 95% CI around the difference, using the variance inflation factor to account for herd level clustering. The non-inferiority margin was 20% for both bacteriological and clinical cure. Generalising estimating equation models were used to determine predictor variables. RESULTS: The bacteriological cure percentage, adjusted to account for herd-level clustering, was 8.5 (95% CI=-1.7-21.8)% higher for quarters treated with the novel than the reference product. The adjusted clinical cure percentage was 0.3 (95% CI=-11.2-12.0)% higher for clinical quarters treated with the novel than the reference product. Bacterial species was the only covariate for bacteriological cure (p=0.003), and quarter score at enrolment (indicating udder inflammation) was the only covariate for clinical cure (p=0.032) in the multivariable models. CONCLUSION: The novel combination product was demonstrated to be non-inferior to the reference product with regards to both bacteriological cure and clinical cure. CLINICAL RELEVANCE: Clinicians treating mastitis now have access to this novel combination intramammary product, and demonstration of its non-inferiority compared to the existing reference product will provide options for treatment approaches. The novel product contains fewer antimicrobials; which are of a narrower spectrum of activity.

Tissue Plasminogen Activator Coating on Implant Surfaces Reduces Staphylococcus aureus Biofilm Formation.

Staphylococcus aureus biofilm infections of indwelling medical devices are a major medical challenge because of their high prevalence and antibiotic resistance. As fibrin plays an important role in S. aureus biofilm formation, we hypothesize that coating of the implant surface with fibrinolytic agents can be used as a new method of antibiofilm prophylaxis. The effect of tissue plasminogen activator (tPA) coating on S. aureus biofilm formation was tested with in vitro microplate biofilm assays and an in vivo mouse model of biofilm infection. tPA coating efficiently inhibited biofilm formation by various S. aureus strains. The effect was dependent on plasminogen activation by tPA, leading to subsequent local fibrin cleavage. A tPA coating on implant surfaces prevented both early adhesion and later biomass accumulation. Furthermore, tPA coating increased the susceptibility of biofilm infections to antibiotics. In vivo, significantly fewer bacteria were detected on the surfaces of implants coated with tPA than on control implants from mice treated with cloxacillin. Fibrinolytic coatings (e.g., with tPA) reduce S. aureus biofilm formation both in vitro and in vivo, suggesting a novel way to prevent bacterial biofilm infections of indwelling medical devices.

Antibiotic Prophylaxis With Trimethoprim/Sulfamethoxazole Instead of Cloxacillin Fails to Improve Inguinal Surgical Site Infection Rate After Vascular Surgery.

BACKGROUND: Surgical site infections (SSIs) and their prevention continue to be a major point of focus in all surgical specialties today. Antibiotic prophylaxis is one of the mainstays in their prevention. Due to the consistently high proportion of infections caused by intestinal flora from the start of our wound surveillance registry in 2005, we conducted a change in prophylactic antibiotic therapy from cloxacillin in 2012 to trimethoprim/sulfamethoxazole (TMP-SMX) in 2013. METHODS: The study included all patients undergoing vascular surgery with groin incisions between March 1 and June 30 in 2012 and 2013, respectively, whereby the antibiotic regime was changed in between the 2 sampling periods. The diagnosis of SSI was based on clinical examination and microbiological results. RESULTS: Two hundred nineteen patients with inguinal incisions were included in the analysis: 105 in the cloxacillin group of which 19% had SSI and 114 in the TMP-SMX group with an SSI rate of 18% (P = .77), without differences between the 2 groups regarding age, gender, proportion of emergency surgery, type of surgery, or frequency of concomitant foot ulcers. The high proportion of infections caused by intestinal flora between time periods was unchanged (67% vs 81%, P = .34). CONCLUSION: There was no difference between the 2 groups, suggesting that the choice of antibiotic prophylaxis had a limited role in preventing SSI at our center. Despite this, the lower cost and ease of the administration of TMP-SMX can be seen as convincing advantages.

Evaluation of the efficacy of intramuscular versus intramammary treatment of subclinical Streptococcus agalactiae mastitis in dairy cows in Colombia.

A randomized controlled trial was performed in 17 Colombian dairy herds to determine the cure risk among cows subclinically infected with Streptococcus agalactiae exposed to 2 antibiotic therapies. Composite milk samples were collected before milking at the onset of the trial (pretreatment) and 2 subsequent times over a period of approximately 63 d. The intramammary application (IMM) of ampicillin-cloxacillin was compared with the intramuscular application (IM) of penethamate hydriodide, and cure risks after an initial and retreatment application were assessed. Cure risk after the initial treatment was higher (82.4%) for the IMM treatment than for IM therapy (65.8%). However, no difference was observed in the cure risk of refractory cases after retreatment (IMM=52.6% vs. IM=51.2%). The cumulative cure risk (both initial and retreatment) was 90.4 and 82.9% for the IMM and IM products, respectively. A 2-level random effects logistic model that controlled for pretreatment cow-level somatic cell count, indicated that IM treatment (odds ratio=0.37) had a lower cure risk than IMM and a tendency for a lower cure risk with increasing baseline somatic cell count. Our findings suggest that both products and administration routes can reduce the prevalence of S. agalactiae in affected herds, but the IMM product had a better efficacy in curing the infection. In addition to the treatment protocol, the cow somatic cell count should be considered when making management decisions for cows infected with S. agalactiae.