Effect of a pre-milking teat foam and a liner disinfectant on the presence of mesophilic and (proteolytic) psychrotrophic bacteria prior to milking.

Simple SummaryThe benefits of pre-milking teat disinfection have varied depending on management, practices and bacterial strains present in the environment, with some studies stating a reduction in the incidence of new infections and other studies stating little benefit of pre-milking teat disinfection. Furthermore, the effectiveness of pre-milking teat disinfection using foam has not previously been evaluated in a pasture-based dairy herd. This study has shown little benefit of applying a foaming pre-milking teat disinfectant in early lactation in a pasture-based dairy herd. However, the foaming teat disinfectant reduced bacterial counts on teat skin and may reduce the bacterial contamination of milk.The objective of this study was to determine the benefit of pre-milking teat foam disinfection on the prevention of new infections by contagious and environmental bacteria in two spring calving herds managed outdoors (Herd 1 [H1]; 331 cows and Herd 2 [H2]; 142 cows). Four pre-milking teat preparation treatments were applied post calving; with each herd receiving two treatments; using a split udder design (for approx. 15 weeks). These treatments included; (1) ‘water wash, foam application and dry wipe (WFD) in H1′; (2) ‘water wash and dry wipe (WD)’ in H1; (3) ‘foam application and dry wipe (FD)’ in H2; (4) ‘no teat cleaning preparation (NP)’ in H2. Individual quarter foremilk samples were collected on four occasions and all clinical and sub-clinical cases were recorded. The mean SCC of quarter foremilk samples was 134 × 103 cells/mL and 127 × 103 cells/mL for WD and WFD, respectively, and 109 × 103 cells/mL and 89 × 103 cells/mL for NP and FD, respectively (p > 0.05). Lower bacterial counts were observed on teat skin that received a foaming treatment. Pre-milking teat disinfection using a foaming product may be of little benefit, in early lactation, for a pasture-based dairy herd.

Infected leg ulcers are major health problems resulting in morbidity and disability and are usually chronic and refractory to antimicrobial treatment. The present study is aimed at determining the bacteria involved in leg ulcers and their resistance patterns to commonly used antibiotics as well as to determine whether Aloe Vera has antibacterial activity against multi-drug resistant organisms and promotes wound healing. A total of 30 cases with leg ulcers infected with multi-drug resistant organisms were treated with topical aloe vera gel and 30 age and sex-matched controls were treated with topical antibiotics. Culture and sensitivity was done from the wounds on alternate days and the ulcer was clinically and microbiologically assessed after 10 days. The results were compiled and statistically analysed. Cultures of the study group who were using aloe vera dressings showed no growth by the fifth day in 10 (33.3%) cases, seventh day in another 16 (53.3%) and ninth day in two of the remaining four cases (6.7%) while in two (6.7%) cases there was no decrease in the bacterial count. This means that of the 30 cases, 28 showed no growth by the end of 11 days while two cases showed no decrease in bacterial count. Growth of bacteria in study group is decreased from 100% (30 cases) to 6.7% (2 cases) by day 11 with P<0.001. Cultures of the control group did not show any decrease in the bacterial growth by day 11. Aloe vera gel preparation is cheap and was effective even against multi-drug resistant organisms as compared to the routinely used topical anti-microbial agents.

In the present study, the therapeutic potential of purified and well-characterized bacteriophages was evaluated in thermally injured mice infected with Klebsiella pneumoniae B5055. The efficacy of five Klebsiella phages (Kpn5, Kpn12, Kpn13, Kpn17, and Kpn22) was evaluated on the basis of survival rate, decrease in bacterial counts in different organs of phage-treated animals, and regeneration of skin cells as observed by histopathological examination of phage-treated skin. Toxicity studies performed with all the phages showed them to be non-toxic, as no signs of morbidity and mortality were observed in phage-treated mice. The results of the study indicate that a single dose of phages, intraperitoneally (i.p.) at an MOI of 1.0, resulted in significant decrease in mortality, and this dose was found to be sufficient to completely cure K. pneumoniae infection in the burn wound model. Maximum decrease in bacterial counts in different organs was observed at 72 h post infection. Histopathological examination of skin of phage-treated mice showed complete recovery of burn infection. Kpn5 phage was found to be highly effective among all the phages and equally effective when compared with a cocktail of all the phages. From these results, it can be concluded that phase therapy may have the potential to be used as stand-alone therapy for K.pneumoniae induces burn wound infection, especially in situations where multiple antibiotic-resistant organisms are encountered.

Closed postoperative peritoneal lavage (CPPL) with chlorhexidine gluconate reduces the number of intraperitoneal bacteria and improves the outcome of intra-abdominal infection. Laboratory animal trial. Intra-abdominal infection was produced in mice by the cecal ligation and puncture technique. After 16 to 18 hours, the animals underwent relaparotomy and placement of an intra-abdominal catheter for CPPL. In the first experiment animals were randomly divided into 4 groups: no lavage (served as a control), CPPL with chlorhexidine. CPPL with cefoxitin, and CPPL with lactated Ringer solution (LR). Lavage was continued intermittently every 8 hours for 24 hours. All animals received systemic cefoxitin every 8 hours for 7 days. Mortality was recorded every 8 hours for 10 days. In the second experiment, animals were divided into 3 groups: no lavage (served as a control), CPPL with chlorhexidine, and CPPL with LR. Lavage was continued intermittently every 8 hours for 24 hours. The animals were killed 48 hours after reoperation. Bacterial counts from peritoneal fluid and biopsy specimens, as well as peritoneal white blood cell counts, were measured before and after lavage. Closed postoperative peritoncal lavage with chlorhexidine reduced mortality from 71% in a control group to 37% (P = .003). There was no survival benefit in either the CPPL with cefoxitin (91% mortality) (P = .14) or CPPL with LR groups (90% mortality) (P = .17). The statistically significant findings of analysis of variance evaluation demonstrated a decrease in bacterial counts after cecal excision in all 3 groups. There was a greater reduction in bacterial counts in the chlorhexidine group compared with the control group (P<.05). Bacterial counts decreased in peritoneal fluid, as well as in tissue biopsy specimens, after cecal excision. White blood cell counts significantly decreased after cecal excision in all 3 groups. There was no difference in white blood cell counts between the groups. Correlation analyses demonstrated weak interaction between bacterial and white blood cell counts before or after treatment in all the groups. Pearson r ranged from -0.37 to +0.35, none of which were statistically significant. In our experiments chlorhexidine lavage resulted in a 50% reduction in mortality and a significant reduction in bacterial counts compared with the control group. There was no survival benefit from lavage with either cefoxitin or LR. There was no reduction in bacterial counts in the LR group relative to the control group. Thus, the survival benefit and the reduction in bacterial numbers are attributed to the antibacterial properties of chlorhexidine rather than to the mechanical washing of the abdominal cavity. Closed postoperative peritoneal lavage with 0.05% chlorhexidine gluconate might be useful in the multimodal treatment of intra-abdominal infection.

Peri-operative antifungal prophylaxis is increasing, both systemically with intravenous infusion and in dipping solutions for use with hydrophilic penile prosthesis (PP) surfaces. In this study, we explore whether amphotericin B or fluconazole decreases vancomycin and gentamicin (VG) antibiotic efficacy when utilized as dips for the hydrophilic PP surface. We compared antibiotic activity of PP discs dipped for 3min in normal saline (NS), 2mg/mL vancomycin and 160μg/mL gentamicin in NS, 0.05mg/mL amphotericin B in VG (VGA), or 2mg/mL VG constituted in a 20mg/mL fluconazole in NS solution. Discs were incubated in 1 × 105 CFU/mL of methicillin-sensitive Staphylococcus aureus (MSSA) for 48h, then adherent bacteria were suspended, plated, and counted. The effect of intraoperative irrigation on the antibacterial activity after a prophylactic dip was assessed by submersion in NS, VG, VGA, or VGF for 2min followed by incubation with MSSA. Zones of Inhibition (ZOI) were obtained by performing Kirby-Bauer Disc Diffusion Assays against S. aureus, Escherichia coli, and Klebsiella pneumoniae. Average bacterial counts (CFU/mL) and ZOI (mm) following a series of treatment protocols of PP discs were obtained. There were significant decreases in bacterial counts in all treatment groups (VG, VGA, and VGF) relative to NS control (P < .001). There were no significant differences in bacterial counts between the treatment groups (P > .05). The greatest decrease in bacterial counts was measured with the VGF/VGF regimen (~6 log, P ≤ .0001). ZOI measurements supported unaltered antibacterial activity across all treatment groups against the different clinical strains. Adding antifungals to the antimicrobial dip solution does not diminish the antimicrobial efficacy of VG antibiotics on the hydrophilic PP surface. This is the first study to demonstrate that the addition of antifungal agents to the antibiotic dip does not diminish the antibacterial efficacy of antimicrobials bound to the hydrophilic surface. Limitations of this study include the use of in vitro studies, which serve as a proxy for in vivo practices and may not be entirely accurate nor translatable in a clinical setting. The hydrophilic PP surface is versatile. The addition of antifungals to dip and irrigation solutions may provide broader antimicrobial coverage in PP implantation without compromising antibacterial protection, favoring fluconazole over amphotericin B.

To assess the potential for contamination of wastewaters from pig farming. Wastewaters from pig farming were stored in a tank. After 0, 30, 60, 90, and 120 days of hydraulic retention, they were added to lysimeters filled with argillaceous, sandy, or medium soil. Finally, these lysimeters were submitted to simulations of either a rainy season or a dry season. The number of colony-forming units (CFUs) of total coliforms, fecal coliforms, and fecal streptococci was measured in the effluents of the storage tank (for the various periods of hydraulic retention), in the percolate from the lysimeters, and in the three types of soil. The microbiological analyses were carried out using the membrane filter technique. The pH analyses were done potentiometrically. For the three microorganisms, the largest decrease in bacterial counts in the storage tanks occurred with 90 or 120 days of retention. There was a marked decrease in the bacterial count in the percolates of the three soils. For the three soil types the greatest reduction in bacterial counts was found in medium soil, due to its acidity (pH < 7.0). Hydraulic retention was not sufficient to ensure the sanitary adequacy of the wastewaters and their use for irrigation, given that fecal coliform values were above 1 000 CFU per 100 mL. Therefore, adding the residues to the soil was considered a second stage of treatment. The retention of wastewaters followed by adding them to soil was effective in minimizing the contaminating effect of pig farming residues. The storage time for wastewaters from pig farming could be decreased from 120 to 90 days.

Introduction During revision penile prosthesis (PP) surgery, existing implant components may be reused (i.e., repair of an impending cylinder extrusion, reservoir herniation, or pump relocation). To date, no studies have evaluated the ability of the existing hydrophilic PP surface to rebind antiseptic solutions during revision surgery and potentially confer antimicrobial protection. Objective We hypothesize that the PP hydrophilic surface coating retains its binding properties and maintains antimicrobial efficacy comparable to that of a new implant ex vivo. Methods This study does not constitute human research, as discarded materials without the use of patient identifiers were used. 3 reservoirs and 2 cylinders were sourced from 3 patients who underwent revision Coloplast Titan PP surgery. Congo Red staining of the implant was performed immediately after removal in the operating room and after sterilization in the lab. Congo Red staining is used by Coloplast to evaluate the integrity of the hydrophilic coating. A new, sterile reservoir was used as a control. Sterile 8 mm PP discs were submerged for 3 minutes in 3 mL of normal saline (NS), 0.05% chlorhexidine gluconate (CHG), or a 2 mg/mL vancomycin and 160 μg/mL gentamicin (VG) solution, rinsed in NS for five seconds, then incubated with 10^5 colony-forming units per milliliter (CFU)/mL of methicillin-sensitive Staphylococcus aureus ATCC25923 in trypticase soy broth (TSB) for 48 hours. Samples were rinsed with PBS and biofilm was removed by shaking in 0.3% Tween-20. Suspended bacteria were serially diluted, plated onto 3 M PetriFilms, and counted. Sterile 8 mm PP discs were submerged for 3 minutes in either fluorescein-isothiocyanate (FITC) labelled (Sigma Aldrich, St. Louis, MO) or unlabeled vancomycin at 2 mg/mL, after which the discs were rinsed in NS. Initially, the unlabeled PP discs were viewed to assess for any baseline fluorescence, after which unlabeled and FITC-vancomycin PP discs were viewed. Quantification of all fluorescence was done via ImageJ. Mann–Whitney U and one-way ANOVA tests were performed to compare outcomes, p &amp;lt; 0.05 considered significant. Results Implants stained evenly with Congo Red by gross visualization immediately after removal in the operating room and after sterilization in the lab (Fig. 1a). Average bacterial counts with 95% CI are plotted in Fig. 1b. For all implants, there were significant decreases in bacterial counts in the VG groups relative to NS (p &amp;lt; 0.01). However, only two (40%) of the 0.05% CHG implants exhibited significant (p &amp;lt; 0.05) decreases in bacterial counts relative to NS. Bacterial counts on the control implant were similar to explanted PP devices across all three treatment groups (p &amp;gt; 0.05). Average fluorescence with 95% CI are plotted in Fig. 1c with images shown in Fig. 1d. Significant increases in fluorescence were present across all implants in the FITC-vancomycin labeled group relative to unlabeled vancomycin controls (p &amp;lt; 0.0001). Conclusions Hydrophilic PP surfaces remain viable and bind vancomycin based on ex-vivo Congo Red staining and FITC-vancomycin binding studies. The hydrophilic surfaces also retain antimicrobial properties and reduce bacterial binding, while VG was more effective than 0.05% CHG. Further studies are indicated to identify the clinic benefit of these findings. Disclosure Yes, this is sponsored by industry/sponsor: Coloplast. Clarification: Industry funding only - investigator initiated and executed study. Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast and Boston Scientific.

The in vivo efficacies of piperacillin, piperacillin plus tazobactam, ticarcillin, ticarcillin plus clavulanic acid, piperacillin plus clavulanic acid, and cefotaxime were compared in a mouse model of pneumonia induced by the SHV-1 beta-lactamase-producer Klebsiella pneumoniae. Each antibiotic was injected either once intraperitoneally at 24 h postinfection or at repeated times during 24 h. The efficacies of the drugs and therapeutic protocols were assessed by counting viable bacteria recovered from the lungs of mice sacrificed at selected times. No emergence of beta-lactam-resistant organisms was detected. Ticarcillin at 300 mg/kg was ineffective. Repeated injections of piperacillin at 300 mg/kg, either alone or in combination with tazobactam (8:1), led to a significant decrease in bacterial counts, but this was followed by bacterial regrowth. The pharmacokinetic analysis demonstrated that this short-lasting antibacterial effect was not due to a failure of piperacillin and/or tazobactam to penetrate the lungs. The combinations of ticarcillin at 300 mg/kg plus clavulanic acid (15:1) and piperacillin at 300 mg/kg plus tazobactam (4:1) were proven to be effective in that they decreased the bacterial burden in the lungs from 10(5) to < 10(3) CFU. This dose effect of tazobactam can be explained by its dose-dependent penetration in the lungs. Cefotaxime at 100 mg/kg and the combination of piperacillin (slightly hydrolyzed by SHV-1) at 300 mg/kg plus clavulanic acid (15:1) led to the best efficacy. Both of these treatments induced a decrease in bacterial counts of nearly 4 log10 units. The survival rates correlated with the quantitative measurements of in vivo bacterial killing. These experimental results obtained from the restricted animal model used here may help in the design of further protocols for clinical trials.

MP76-14 PROPHYLACTIC DIPS AND IRRIGATION SOLUTIONS CAN CONSIDERABLY ALTER THE ANTIMICROBIAL EFFICACY OF INFLATABLE PENILE PROSTHESIS HYDROPHILIC SURFACE COATINGS

Three experiments involving 214 lamb carcasses were conducted to determine the effects of elevated chilling temperature, carcass drying, wrapping in polyvinyl chloride (PVC) film and bacteriostatic agents on shrinkage, bacterial counts and palatability traits. Chilling of lamb carcasses at 16 C for 24 hr immediately postmortem was associated with increased (P<05) tenderness, but was accompanied by increased (P<05) bacterial growth. High velocity air drying decreased (P<05) bacterial counts, but increased (P<05) postmortem shrinkage. Use of PVC film was associated with reduced (P<05) shrinkage and improved carcass appearance, but also with increased (P<05) bacterial growth. Dilute solutions (.02%) of chlorine effected a two log sub 10 reduction in bacterial counts on unwrapped lamb carcasses, yet had no effect on the flavor of cooked chops. Bacteriostatic agents were most effective in reducing bacterial counts when they were applied to carcasses immediately postmortem; however, decontamination after 7 days of 0 C cooler storage resulted in a one log sub 10 reduction in bacterial counts. Elevated temperature (16 C) chilling of lamb carcasses is feasible for enhancing lamb tenderness without increasing bacterial counts, if the carcasses are rinsed immediately after slaughter with a .02% chlorine solution. Use of bacteriostatic agents on lambs wrapped with PVC film in an attempt to simultaneously curtail microbial growth and shrinkage did not result in consistent decreases in bacterial counts.

The effect of protein binding of cefoperazone (89.3% bound to rabbit serum) on antibacterial activity in serum was tested in a model that simulated a closed-space infection in a neutropenic host. Four gram-negative bacilli were tested in the model with cefoperazone doses of 20 and 200 mg/kg administered intramuscularly every 6 h for 16 doses. Cefoperazone efficacy was measured at 92 h by determining the log10 decrease in bacterial count from that of the control for five paired studies with three isolates. A significantly better response was demonstrated when the free (non-protein-bound) drug concentration exceeded the MICs and MBCs for the infecting microorganisms at the infection site at all times (P less than 0.005). This supports the concept that free (unbound) drug is the active component in treating bacterial infections.

Debridement plays a critical role in wound management. In addition to removing necrotic tissue, debridement can eliminate bacteria frequently harbored within the tissue. This study evaluated a novel debridement method that uses plasma-based radiofrequency technology to remove tissue and bacteria. Coblation is a technology that uses radiofrequency energy to excite the electrolytes in a conductive medium, such as saline, to create a precisely focused plasma. This plasma field contains highly energized particles that possess sufficient energy to break tissue molecular bonds, causing the tissue to dissolve at relatively low temperatures (typically 40 °C to 70 °C). Eighteen deep dermal wounds measuring 22 mm × 22 mm × 3 mm deep were created on pigs. Wounds were inoculated with methicillin-resistant Staphylococcus aureus USA300 (MRSA USA300) in combination with shrapnel and then covered with a polyurethane dressing for 24 hours. Wounds were then randomly assigned to one of the 3 treatment groups: (1) Coblation, (2) surgical debridement, and (3) no debridement. Wounds were biopsied on days 0, 5, 9, and 12, and specimens were processed for MRSA counts using selective media. Statistical analysis was performed using IBM SPSS statistics 27 using one-way ANOVA. Comparison between coblation and surgical debridement showed a decrease in bacterial count in all assessment times. The lowest bacterial count in all assessment times was observed in wounds debrided with coblation showing a statistically significant (P ≤ .05) decrease in more than 2 Log CFU/g on days 0, 5, and 9 compared to no debridement. On day 12, coblation-debrided wounds exhibited 6.10 ± 0.22 Log CFU/g, and this value represents 99.99% of reduction compared with non-debrided wounds (P ≤ .05). More than 96% of reduction (P ≤ .05) resulted in wounds treated with coblation compared with surgically debrided. Reducing MRSA bacterial infection counts, especially of biofilm-associated organisms, in combination with shrapnel may have important clinical implications, especially for the military personnel. Further research into the use of this technology in wound management is warranted.

After treatment of encapsulated Klebsiella pneumoniae with salicylate or bismuth compounds, phagocytic uptake by human peripheral white blood cells or rat alveolar macrophages was assessed. Without salicylate pretreatment of bacteria, a 30-60% net increase in viable bacteria resulted in phagocytic assays after a 1 hour incubation. With salicylate pretreatment, dose-related decreases in bacterial counts were seen, achieving a maximal reduction of 60% with 240 microM salicylate pretreatment. Bacterial variants producing less capsule were more serum sensitive and more readily phagocytosed. Micrographs of Giemsa-stained cells revealed phagocytic uptake of multiple bacteria after salicylate pretreatment, but virtually no uptake of untreated bacteria. Opsonization with polyclonal antiserum decreased bacterial cell counts by 20% without and by 90% with salicylate pretreatment of bacteria. Pretreatment of bacteria with bismuth salts also enhanced opsonophagocytosis of encapsulated bacteria. Thus, agents known to reduce capsule expression in K. pneumoniae also enhance phagocytic uptake of bacteria.

Osteomyelitis is an inflammatory bone disease caused by pyogenic bacteria. The advantages of localized biodegradable therapy for osteomyelitis include high local antibiotic concentration at the site of infection and obviation of the need for removal of the implant after treatment. The purpose of this study was to develop and evaluate a biodegradable implantable delivery system containing gatifloxacin (GAT) for the localized treatment of osteomyelitis, experimentally induced by methicillin resistant Staphylococcus aureus (MRSA). Implants, prepared by solvent casting technique, showed reasonable tensile strength. DSC examination indicated that GAT is present in an amorphous form in the implant. The in vitro release of GAT showed a profile characterized by an initial burst followed by a second stage of gradual delivery over 27 days. The in vivo release study revealed that GAT concentrations achieved during the first 3 weeks after implantation exceeded the MIC of GAT against MRSA by > 100,000 times. Bacterial tibial bone count performed in rabbits tibia 2 and 4 weeks after implantation of GAT implant in infected bone indicated complete eradication of infection in all treated rabbits as indicated by the significant decrease in bacterial count. The results show that the proposed implant may have a promising role in the therapeutic approach to osteomyelitis.

Efficacy of a New Premilking Teat Disinfectant Containing a Phenolic Combination for the Prevention of Mastitis