Tryptic Soy Broth Research Articles

Expression of biofilm-associated genes in Staphylococcus aureus during storage of platelet concentrates

Background and objectivesIn transfusion medicine, the safety of platelet concentrates (PCs) is a major concern on account of contamination, mostly with Staphylococcus species. One of the most common contaminants is Staphylococcus aureus, which forms bacterial biofilms in PCs, posing a safety risk for transfusion patients. In this study, we investigate the contributions to biofilm formation of eno, ebps, and fib genes encoding surface proteins and of genes from the ica operon (icaA and icaD) encoding polysaccharide intercellular adhesin (PIA), along with their expression in bacteria grown in glucose-supplemented trypticase soy broth (TSBg) and PCs. Materials and methodsTwo strains of S. aureus (2039 and 2110) captured during routine PC screening were tested for biofilm formation in TSBg and under PC storage conditions, with mRNA collected at five time points and analyzed to determine expression of eno, ebps, fib, icaA, and icaD and their contributions to biofilm formation in both media. ResultsIn TSBg, S. aureus strain 2039 formed weak biofilms while 2110 formed strong. biofilms; however, in PCs, both strains formed strong biofilms. During biofilm formation, expression levels of icaA and icaD in both strains were generally significantly higher in TSBg than PCs. In contrast, expression of eno, ebps, and fib genes tended to be significantly higher under PC storage conditions. ConclusionThis study demonstrated that expression of genes involved in biofilm formation can be affected by growth media. Further investigation is needed to understand biofilm formation in the PC milieu and enhance transfusion safety.

Target Mechanism of Iturinic Lipopeptide on Differential Expression Patterns of Defense-Related Genes against Colletotrichum acutatum in Pepper.

Bacillus subtilis KB21 is an isolate with broad spectrum antifungal activity against plant pathogenic fungi. Our aim was to produce and purify antifungal lipopeptides via fermentation using B. subtilis KB21 and verify their antifungal mechanism against pepper anthracnose. When the KB21 strain was cultured in tryptic soy broth medium, the antifungal activity against pepper anthracnose correlated with biosurfactant production. However, there was no antifungal activity when cultured in Luria-Bertani medium. KB21 filtrates showed the highest degree of inhibition of mycelia (91.1%) and spore germination (98.9%) of Colletotrichum acutatum via increases in the biosurfactant levels. Using liquid chromatography-mass spectrometry (LC-MS) and LC-tandem MS (LC-MS/MS) analyses, the component with antifungal activity in the fermentation medium of the KB21 strain was determined to be the cyclic lipopeptide (CLP) antibiotic, iturin A. When the iturin fractions were applied to pepper fruits inoculated with conidia of C. acutatum, the lesion diameter and hyphal growth on the fruit were significantly suppressed. In addition, iturin CLP elevated the gene expression of PAL, LOX, and GLU in the treatments both with and without following fungal pathogens. Overall, the results of this study show that iturin CLPs from B. subtilis KB21 may be potential biological control agents for plant fungal diseases.

Colistin Action Against Planktonic Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic human pathogen that causes nosocomial, acute, and chronic infections in patients with conditions such as cystic fibrosis, severe burns, and cancer. P. aeruginosa is associated with increased patient morbidity, mortality, and healthcare costs and is known for its persistence of infections. P. aeruginosa is resistant to many antibiotics; however, most strains are susceptible to colistin. The World Health Organization has identified antimicrobial resistance as a major threat and Antimicrobial Stewardship Programs (ASP) have been initiated. ASP goals are to improve patient outcomes, optimize patient safety, reduce antimicrobial resistance, and control healthcare costs. Recommendations to reduce antimicrobial resistance include optimizing the use of antimicrobials and preventing the transmission of drug‐resistant organisms. Using antimicrobic agents wisely leads to optimization of their use. For these reasons, we sought to adopt a model system for testing minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) levels for standardized strains of P. aeruginosa (ATCC strains 10145, 27853, 1744, CRM‐9027, 9721) using standardized methods. This study sought to compare results of standardized analysis that used Mueller‐Hinton Broth (MHB), the recommended and standardized growth medium, or tryptic soy broth (TSB), the growth medium used in many labs with published MIC and MBC reports. Given the ASP recommendations of optimizing use of antimicrobial agents, it is important to know the impact of variations in and deviations from standardized MIC and MBC methodologies in reporting of research results relevant to antimicrobic agents. This comparison study tested the assumption that MIC and MBC results are the same regardless of whether MHB or TSB is used as the growth medium. Preliminary results suggest that MIC and MBC values obtained by using TSB or MHB may display some degree of variability.

Sodium benzoate and sodium bisulfate as preservatives in apple juice and alternative sanitizers for washing cherry tomatoes

Unpasteurized apple ciders and fresh produce have been linked to multistate outbreaks due to contamination by foodborne pathogens. Organic acids such as benzoic acid are effective antimicrobials, and acidified sodium benzoate (NaB) has been reported to be effective in reducing pathogens inoculated on cherry tomatoes and preventing cross-contamination. Sodium bisulfate (SBS) is a powerful acidulant but has not been studied in combination with NaB. The objective of the present study was to characterize the antibacterial activity of SBS and its combination with NaB in tryptic soy broth (TSB) and apple juice, as well as washing cherry tomatoes. The minimum inhibitory concentration and minimum bactericidal concentration of SBS were all 0.5% w/v (corresponding to TSB medium pH of 4.30) and 1.0% w/v (corresponding to TSB medium pH of 2.88), respectively, for Escherichia coli O157:H7 ATCC 43895, Salmonella Enteritidis ATCC 13076, and Listeria monocytogenes Scott A. In TSB, the triple combination of 1.0% w/v SBS, 0.1% w/v NaB, and 0.02% w/v oregano oil (OO) showed the faster inactivation rate of the three bacteria than treatments with one or two antimicrobials; the activity of double combinations followed the order of 0.1% w/v NaB +1.0% w/v SBS > 0.1% w/v NaB +0.5% w/v SBS + 0.02% w/v OO > 0.1% w/v NaB +0.5% w/v SBS. pH was a critical factor in the activity of antimicrobial combinations in TSB, and L. monocytogenes was more resistant than Gram-negative E. coli O157:H7 and S. Enteritis. In apple juice added with 0.05% w/v NaB, 0.25% w/v SBS, and 0.01% w/v OO alone or in combinations, 5 log CFU/mL or greater reductions in 72 h were observed for E. coli O157:H7 and S. Enteritidis in double and triple combinations, while only the triple combination and the SBS-OO combination resulted in the same effect for L. monocytogenes. For cherry tomatoes inoculated with 6.8 log CFU/g E. coli O157:H7, complete decontamination (>6 log CFU/g) was achieved after soaking for 1 min in solutions containing 0.5–1.5% w/v SBS and 0.1% w/v NaB or 1.5% w/v SBS alone, and no pathogens were detected in all wash solutions containing 0.5–1.5% w/v SBS with and without NaB. The lower pH of wash solutions with a higher amount of SBS was a dominant factor in decontamination and prevention of cross-contamination. The present study showed the potential of SBS and its combination with NaB to enhance the safety of apple juice and cherry tomatoes.

PD52-03 EVALUATION OF PROTECTION AGAINST GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA IN A NOVEL IN VITRO BIOFILM MODEL OF PENILE PROSTHESIS

You have accessJournal of UrologyCME1 May 2022PD52-03 EVALUATION OF PROTECTION AGAINST GRAM-POSITIVE AND GRAM-NEGATIVE BACTERIA IN A NOVEL IN VITRO BIOFILM MODEL OF PENILE PROSTHESIS Manish Narasimman, Gregory Plano, Jesse Ory, Sara Schesser Bartra, and Ranjith Ramasamy Manish NarasimmanManish Narasimman More articles by this author , Gregory PlanoGregory Plano More articles by this author , Jesse OryJesse Ory More articles by this author , Sara Schesser BartraSara Schesser Bartra More articles by this author , and Ranjith RamasamyRanjith Ramasamy More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002629.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Late infection, thought to be due to biofilm formation, remains a feared complication after inflatable penile prosthesis (IPP) insertion. Our in vitro model previously showed S. epidermidis, S. aureus, P. aeruginosa, and K. pneumoniae can form significant biofilm on IPPs. P. aeruginosa showed the strongest predilection to grow biofilm. Understanding and preventing this biofilm formation could be a breakthrough in reducing IPP infections. We used our in vitro model to compare growth of different bacterial biofilms on IPPs with and without antibiotics and compare efficacy of antibiotic treated Coloplast Titan® and AMS 700 InhibiZone™ against biofilm formation. METHODS: Sterile IPPs were cut into rings. Coloplast rings were dipped in 10 ml of a 10 mg/ml Rifampin, 1 mg/ml Gentamicin, and deionized water solution and dried. Coloplast and AMS rings were incubated in S. epidermidis, S. aureus, P. aeruginosa, or K. pneumoniae cultures in tryptic soy broth (TSB) for a 2 h attachment period, followed by only TSB for 120 h. We utilized a published and validated method to measure biofilm mass. Rings were fixed with ethanol and biofilm formation measured by spectrophotometer (OD570) after crystal violet staining. RESULTS: Of the bacteria studied, only P. aeruginosa formed significant biofilm on antibiotic treated Coloplast Titan® and AMS 700 InhibiZone™ implant rings. In direct comparison of the implants, no significant difference was found in biofilm formation by P. aeruginosa. CONCLUSIONS: Our novel in vitro model of biofilm formation of IPPs evaluated the effect of a gentamicin/rifampin antibiotic dip on Coloplast Titan® and the anti-infective capacity of minocycline/rifampin precoated AMS 700 InhibiZone™ against various bacteria. Our findings suggest P. aeruginosa can form a significant quantity of biofilm on IPPs even with antibiotic treatments. However, both treated IPPs appear to provide effective coverage against biofilm formation by S. epidermidis, S. aureus, and K. pneumoniae. No significant difference was found between the IPPs in protection against P. aeruginosa. P. aeruginosa should continue to be a specific target of investigation and antibiotic strategies potentially modified to increase coverage against the organism to reduce delayed post-operative IPP infections. Source of Funding: This work was supported by National Institutes of Health Grant R01 DK130991 and Clinician Scientist Development Grant from the American Cancer Society to Ranjith Ramasamy. This work was also supported by the AUA Summer Medical Student Fellowship Award to Manish Narasimman © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e905 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Manish Narasimman More articles by this author Gregory Plano More articles by this author Jesse Ory More articles by this author Sara Schesser Bartra More articles by this author Ranjith Ramasamy More articles by this author Expand All Advertisement PDF DownloadLoading ...

Pectolinarin Inhibits the Bacterial Biofilm Formation and Thereby Reduces Bacterial Pathogenicity.

Bacterial biofilms are a growing problem as it is a major cause of nosocomial infection from urinary catheters to chronic tissue infections and provide resistance to a variety of antibiotics and the host’s immune system. The effect of pectolinarin on the biofilm formation in Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Streptococcus mutans, Streptococcus sobrinus, Staphylococcus aureus, Pseudomonas aeruginosa, Cutibacterium acnes, and Porphyromonas gingivalis was studied in TSBg (tryptic soy broth supplemented with 1% glucose). Pectolinarin inhibited biofilm formation of E. faecalis (IC50 = 0.39 μg/mL), E. faecium (IC50 = 0.19 μg/mL), E. coli (IC50 = 0.25 μg/mL), S. mutans (IC50 = 1.2 μg/mL), S. sobrinus (IC50 = 1.4 μg/mL), S. aureus (IC50 = 0.39 μg/mL), P. aeruginosa (IC50 = 0.9 μg/mL), P. acnes (IC50 = 12.5 μg/mL), and P. gingivalis (IC50 = 9.0 μg/mL) without inhibiting the bacterial growth. Pectolinarin also showed increased susceptibility of antibacterial activity with commercially available antibiotics including ampicillin, vancomycin, streptomycin, and oxytetracyclin against E. faecalis and E. faecium. Finally, pectolinarin dose-dependently reduced the expression of genes including cytolysin genes (cylLS, cylR2 and cylM), quorum sensing (QS) genes (fsrB, fsrC, gelE, ebpA, ebpB, acm, scm and bps), and biofilm virulence genes (esp) of E. faecalis and E. faecium. Pectolinarin reduced the bacterial biofilm formation, activated the antibacterial susceptibility, and reduced the bacterial adherence. These results suggest that bacterial biofilm formation is a good target to develop the antibacterial agents against biofilm-related infections.

PM 7/20 (3) Erwinia amylovora

PM 7/20 (3) <i>Erwinia amylovora</i>

A Variant Carbapenem Inactivation Method (CIM) for Acinetobacter baumannii Group with Shortened Time-to-Result: rCIM-A.

Carbapenem-resistant Acinetobacter baumannii group organisms (CRAB) are challenging because the choice between targeted, new antibiotic drug options and hygiene measures should be guided by a timely identification of resistance mechanisms. In CRAB, acquired class-D carbapenemases (CHDLs) are active against meropenem and imipenem. If PCR methods are not the first choice, phenotypic methods have to be implemented. While promising, the carbapenemase inactivation method (CIM) using meropenem-hydrolysis is, however, hampered by poor performance or overly long time-to-result. We developed a rapid CIM (rCIM-A) with good performance using ertapenem, imipenem, and meropenem disks, 2-h permeabilization and incubation with the test strain in trypticase soy broth, and a read-out of residual carbapenem activity after 6 h, and optionally after 16–18 h. Using clinical isolates and type-strains of Acinetobacter (n = 67) not harboring carbapenemases (n = 28) or harboring acquired carbapenemases (n = 39), the sensitivity of detection was 97.4% with the imipenem disk after 6 h at a specificity of 92.9%. If the inhibition zone around the ertapenem disk at 6 h was 6 or ≤26 mm at 16–18 h, or ≤25.5 mm for meropenem, the specificity was 100%. Because of the high negative predictive value, the rCIM-A seems particularly appropriate in areas of lower CRAB-frequency.

Bacterial profile and antimicrobial susceptibility patterns in cancer patients.

Bloodstream infections have been the leading complications in cancer patients because they are at high risk for antibiotic-resistant bacterial infections. There is increasing evidence from different parts of the world of the high prevalence of antimicrobial-resistant bacterial strains in cancer patients. The burden of the infection is high in developing countries, especially in Ethiopia. Data on bacterial profile and antimicrobial susceptibility patterns among cancer patients in Ethiopia is limited. Thus, this study aimed to determine the predominant bacterial species causing bacteremia and their antibiotic resistance pattern among cancer patients at University of Gondar comprehensive specialized hospital. A hospital-based, cross-sectional study was conducted on 200 study participants from March to July 2021. All cancer patients who developed a fever at the time of hospital visit were included in this study, and their socio-demographic and clinical data were collected using a structured questionnaire. Blood samples (10 mL for adults and 4 mL for children) were collected from each patient, and the collected blood samples were transferred into sterile tryptic soy broth, then incubated at 37°C for 7 days. Tryptic soy broth which showed signs of growth were Gram-stained and sub-cultured on blood agar, chocolate agar, MacConkey agar, and mannitol salt agar. The inoculated plates were then aerobically incubated at 37°C for 18-24 hours and the isolates obtained were identified using standard microbiological methods. Antimicrobial susceptibility tests were done using a modified Kirby-Bauer disk diffusion technique following CLSI 2021 guidelines. Data were entered using EPI data version 4.6 and analyzed with SPSS version 20. In this study, out of 200 cancer patients included and 67.5% (135/200) of them were males. The majorities of study participants, 56% (113/200) of cancer patients were pediatrics and 26.5% (53/200) of them belong under five years of age. Out of 200 patient samples that had undergone culture, 27% (54/200) samples had bacterial growth. Gram-positive bacterial isolates were predominant, 61.1%, and S. aureus was the predominant Gram-positive isolate, (51.5.6%), followed by coagulase-negative staphylococci (48.5%). Moreover, K. pneumoniae (47%) and P. aeruginosa (29.5%) were the most common Gram-negative bacterial isolates. Among patients who had BSIs, the highest prevalence of BSIs was observed among males (66.7%), and in pediatrics cancer patients (44.2%). Pediatric study participants were more venerable to bloodstream infection (P = 0.000) compared to adult participants. Meropenem (100%), amikacin (100%), piperacillin/tazobactam (72.3%), and ceftazidime (73.5%) were effective against for Gram-negative isolates while cefoxitin (81.2%) and penicillin (70.5%) were effective for Gram-positive isolates. Additionally, most Gram-negative and Gram-positive bacterial isolates were sensitive for gentamycin (75.9%). Multidrug resistance was seen among 17.1% bacterial isolates, and MDR in Gram-negative and Gram-positive bacteria were 83.3% and 16.7%, respectively. Gram-negative bacterial isolates showed a high prevalence of MDR than Gram-positive isolates. BSI's remains an important health problem in cancer patients, and Gram-positive bacteria were more common as etiologic agents of BSIs in cancer patients. S. aureus was the dominant bacteria followed by CoNS, K. pneumoniae, and P. aeruginosa. Multidrug-resistant isolates found in cancer patients and routine bacterial surveillance and study of their resistance patterns may guide successful antimicrobial therapy and improve the quality of care. Therefore, strict regulation of antibiotic stewardship and infection control programs should be considered in the study area.

Evaluation of Bacteria in a Novel In Vitro Biofilm Model of Penile Prosthesis

BackgroundDelayed infection, thought to be due to gradual biofilm formation, remains a feared complication after inflatable penile prosthesis (IPP) insertion. Understanding and preventing biofilm formation is necessary to prevent infections. AimTo develop an in vitro model and compare growth of biofilm by different bacteria on IPPs and evaluate the anti-infective efficacy of the Coloplast Titan and AMS 700 InhibiZone. MethodsSterile IPPs (Coloplast) were cut into rings and incubated with S. epidermidis, S. aureus, P. aeruginosa, A. baumannii, or K. pneumoniae cultures in tryptic soy broth (TSB) (4 hour) to ensure adequate bacteria attachment, and then in only TSB (120 hours) to allow for biofilm formation. Rings were fixed with ethanol and biofilm measured by spectrophotometer (OD570) after crystal violet staining. This methodology was repeated for S. epidermidis and P. aeruginosa with Coloplast rings dipped in 10 ml of a 10 mg/ml Rifampin, 1 mg/ml Gentamicin, and deionized water solution and undipped AMS InhibiZone rings. Crystal violet assay (OD570) was repeated after incubation within bacteria (2 hour), and then only TSB (120 hours). OutcomesThe primary outcome of the study was OD570 readings, indirectly measuring biofilm mass on implant rings. ResultsS. epidermidis, S. aureus, A. baumannii, P. aeruginosa, and K. pneumoniae all formed significant biofilm. P. aeruginosa showed the strongest predilection to grow biofilm on IPPs. P. aeruginosa also formed significant biofilm on antibiotic-treated Coloplast and AMS rings, while S. epidermidis was inhibited. No significant difference was found in biofilm inhibition between the implants. Clinical TranslationOur findings suggest gram-negative bacteria may form biofilm more proficiently and quickly on IPPs than gram-positive organisms. Commonly used antibiotic treatments on IPPs may be effective against S. epidermidis but not against P. aeruginosa biofilm formation. Strengths & LimitationsThis is the first study comparing biofilm formation by different bacteria organisms on IPPs and the inhibitive ability of Coloplast and AMS implants against biofilm formation. Clinical data on organisms responsible for infected IPPs is needed to determine the clinical relevance of our findings. ConclusionOur novel in vitro model of biofilm formation of IPPs evaluated the effect of a gentamicin/rifampin antibiotic dip on Coloplast Titan implants and the anti-infective capacity of the minocycline/rifampin precoated AMS 700 InhibiZone against S. epidermidis and P. aeruginosa. P. aeruginosa was able to grow on both antibiotic-treated implants, with no significant difference, and should continue to be a specific target of investigation to reduce delayed post-operative IPP infections.Narasimman M, Ory J, Bartra SS, et al. Evaluation of Bacteria in a Novel In Vitro Biofilm Model of Penile Prosthesis. J Sex Med 2022;19:1024–1031.

The First Complete Genome Resource of a Ralstonia solanacearum Phage UAM5 from Colombia.

The First Complete Genome Resource of a Ralstonia solanacearum Phage UAM5 from Colombia.

Effect of pH and Salinity on the Ability of Salmonella Serotypes to Form Biofilm.

Salmonella is a major cause of food-borne infections in Europe, and the majority of human infections are caused by only a few serotypes, among them are Salmonella enterica subsp. enterica serotype Enteritidis (hereafter Salmonella Enteritidis), Salmonella Typhimurium, and the monophasic variant of S. Typhimurium. The reason for this is not fully understood, but could include virulence factors as well as increased ability to transfer via the external environment. Formation of biofilm is considered an adaptation strategy used by bacteria to overcome environmental stresses. In order to assess the capability of different Salmonella serotypes to produce biofilm and establish whether this is affected by pH and salinity, 88 Salmonella isolates collected from animal, food, and human sources and belonging to 15 serotypes, including those most frequently responsible for human infections, were tested. Strains were grown in tryptic soy broth (TSB), TSB with 4% NaCl pH 4.5, TSB with 10% NaCl pH 4.5, TSB with 4% NaCl pH 7, or TSB with 10% NaCl pH 7, and biofilm production was assessed after 24 h at 37°C using crystal violet staining. A linear mixed effect model was applied to compare results from the different experimental conditions. Among the tested serotypes, S. Dublin showed the greatest ability to form biofilm even at pH 4.5, which inhibited biofilm production in the other tested serotypes. Salmonella Senftenberg and the monophasic variant of S. Typhimurium showed the highest biofilm production in TSB with 10% NaCl pH 7. In general, pH had a high influence on the ability to form biofilm, and most of the tested strains were not able to produce biofilm at pH 4.5. In contrast, salinity only had a limited influence on biofilm production. In general, serotypes causing the highest number of human infections showed a limited ability to produce biofilm in the tested conditions, indicating that biofilm formation is not a crucial factor in the success of these clones.

Antimicrobial Coating Efficacy for Prevention of Pseudomonas aeruginosa Biofilm Growth on ISS Water System Materials.

Biofilms can lead to biofouling, microbially induced corrosion, physical impediment and eventual loss in function of water systems, and other engineered systems. The remoteness and closed environment of the International Space Station (ISS) make it vulnerable to unchecked biofilm growth; thus, biofilm mitigation strategies are crucial for current ISS operation and future long duration and deep-space crewed missions. In this study, a space flown bacterial strain of Pseudomonas aeruginosa (PA14) was used as a model organism for its ability to form biofilms. Additionally, a novel antimicrobial coating’s ability to reduce biofilm accumulation on stainless steel, Teflon, titanium, and Inconel (all used in the ISS water treatment and handling systems) was analyzed. Coated materials demonstrated reductions of P. aeruginosa biofilm across all materials when tested in a continuous flow system with tryptic soy broth medium. However, the coating lost efficacy in potato dextrose broth medium. These findings were corroborated via scanning electron microscopy. This study illustrates the fundamental importance of using multiple approaches to test antibiofilm strategies, as well as the specificity in which conditions such strategies can be implemented.

Evaluation of Gram Positive and Gram Negative Bacteria in a Novel In Vitro Biofilm Model of Penile Prosthesis

ABSTRACT Introduction Infection is the most feared complication of inflatable penile prosthesis (IPP), often necessitating complete removal. Late infection after IPP insertion is thought to be due to the slow formation of a biofilm. Understanding and preventing biofilm formation would be a breakthrough in preventing IPP infections. Objective We aimed to develop an in vitro model to compare formation and growth of biofilms on penile implants by bacteria commonly associated with infection. Methods Sterile IPPs (Coloplast Titan) were cut into rings and incubated with S. epidermidis, S. aureus, P. aeruginosa, or K. pneumoniae cultures in tryptic soy broth (TSB) for a 4 h attachment period, and then in only TSB for 120 h. We utilized a published and validated method to measure biofilm mass. Rings were then dipped in deionized water to wash off additional bacteria and either fixed with ethanol (EtOH) or not treated further (no fix). Fixing was employed to preserve biofilm on the rings that otherwise may have been lost during crystal violet staining. Biofilm formation was measured with a spectrophotometer (OD570) after crystal violet staining. Results All bacteria formed substantial biofilm on implant rings as measured by OD570. As expected, the gram-negative bacteria, P. aeruginosa and K. pneumoniae produced significantly more biofilm than the gram-positive S. epidermidis and S. aureus. Interestingly, P. aeruginosa formed the most biofilm by at least a factor of 6 in both testing conditions. The ethanol fixing condition produced more consistent results for the crystal violet assay. Conclusions Our novel in vitro model of biofilm formation of penile implants can be used in future studies to evaluate the effect of different antibiotic dips and anti-infective capacity of pre-coated implants against different bacteria. Our findings suggest gram-negative bacteria form faster and a greater quantity of biofilm on penile implants as compared to gram-positives. P. aeruginosa displayed the strongest predilection to form biofilm on implants compared to all other bacteria studied, and could be investigated as a specific target to reduce delayed post-operative IPP infections. 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, Boston Scientific

Non-Antibiotic Immunomodulatory Combination Treatment for Staphylococcus aureus Infections: In vitro Preliminary Studies I

Despite advancements in prevention measures, infectious mastitis is a common disease of economic significance in cattle. Clinical mastitis affects 20 to 25% of cows each year. Staphylococcus aureus (S. aureus) causes an estimated 10-11.7% of clinical bovine infectious mastitis cases in the US. Antibiotic therapy tends to fail 50% of the time and nature and vaccine immunity usually fails, due to S. aureus’ evasion mechanisms, leading to significant morbidity, chronic mastitis, and culling of such cows. Specific IgYs have been found to inhibit the growth of S. aureus in vitro, but such IgYs have been produced especially for such experiments, commercially available presentations have not been compared to the IgY produced by naturally exposed chickens. In the present study, we compare the impact of two sources of IgY. IgY was obtained commercially and purified from the eggs of chickens naturally exposed to S. aureus (RIR IgY). Their effect on the in vitro growth of S. aureus was compared and the commercial chicken anti-SpA IgY (IgY). This was done by mixing tryptic soy broth cultures of S. aureus with 5, 25, or 125 µg/mL of IgY or RIR IgY (3 tubes per concentration). The result was evaluated by the plate count method. Next, the treated and control broths were sampled and plated at 4, 8, and 12 h. IgY (commercial) showed a powerful inhibitory effect over S. aureus. This effect was sustained for over 12 h when compared to RIR IgY and two respectively to the control. Though the RIR IgY effect was significant; however, it subsided after 8 h. Based on our findings, IgY may have an effective component against S. aureus growth which is more observed in the IgY commercially obtained than the IgY purified chickens which are naturally exposed to S. aureus (RIR IgY).

Comparison of Streptococcus mutans Adhesion on New and Recycled Metal Brackets: An In Vitro Study.

Background: Evaluation of adhesion of Streptococcus mutans on recycled orthodontic brackets is significant, as Streptococcus mutans is the main causative factor in enamel demineralization and many clinicians, in their practice, resort to reconditioning of brackets, as it is cost-effective. Thus, this study aimed to evaluate and compare the adhesion of Streptococcus mutans on new brackets of three different companies (Group I, Group II, and Group III) and brackets recycled by three different recycling methods (RC I: flame heating followed by acid bath; RC II: flame heating followed by ultrasonic cleaning and electropolishing; RC III: flame heating followed by sandblasting and electropolishing).Materials and methods: A total of 10 brackets from each group were incubated with 108 colony-forming units (CFUs) of Streptococcus mutans in trypticase soy broth overnight. The brackets were then washed with phosphate-buffered saline and treated with 0.25% trypsin for 20 minutes followed by vertexing the solution to remove the adhered bacteria and then the solution was plated on the blood agar and incubated overnight. The total viable count of bacteria was quantified.Results: Comparing all the three groups and recycling methods, Group II brackets showed significantly more adhesion, Group I brackets showed lesser adhesion, and Group III brackets showed intermediate adhesion. When comparing recycling methods, all the three methods of recycling with all the three groups showed more bacterial adhesion than the control brackets, which was statistically insignificant (P > 0.05).Conclusion: Recycled brackets showed more bacterial adhesion and electropolishing resulted in reduced bacterial adhesion.

Comparison of decontamination efficacy of two electrolyte cleaning methods to diode laser, plasma, and air-abrasive devices.

To compare the in vitro decontamination efficacy of two electrolytic cleaning methods to diode laser, plasma, and air-abrasive devices. Sixty sandblasted large-grit acid-etched (SLA) implants were incubated with 2ml of human saliva and Tryptic Soy Broth solution under continuous shaking for 14days. Implants were then randomly assigned to one untreated control group (n = 10) and 5 different decontamination modalities: air-abrasive powder (n = 10), diode laser (n = 10), plasma cleaning (n = 10), and two electrolytic test protocols using either potassium iodide (KI) (n = 10) or sodium formate (CHNaO2) (n = 10) solution. Implants were stained for dead and alive bacteria in two standardized measurement areas, observed at fluorescent microscope, and analyzed for color intensity. All disinfecting treatment modalities significantly reduced the stained area compared to the untreated control group for both measurement areas (p < 0.001). Among test interventions, electrolytic KI and CHNaO2 treatments were equally effective, and each one significantly reduced the stained area compared to any other treatment modality (p < 0.001). Efficacy of electrolytic protocols was not affected by the angulation of examined surfaces [surface angulation 0° vs. 60° (staining %): electrolytic cleaning-KI 0.03 ± 0.04 vs. 0.09 ± 0.10; electrolytic cleaning-CHNaO2 0.01 ± 0.01 vs. 0.06 ± 0.08; (p > 0.05)], while air abrasion [surface angulation 0° vs. 60° (staining %): 2.66 ± 0.83 vs. 42.12 ± 3.46 (p < 0.001)] and plasma cleaning [surface angulation 0° vs. 60° (staining %): 33.25 ± 3.01 vs. 39.16 ± 3.15 (p < 0.001)] were. Within the limitations of the present in vitro study, electrolytic decontamination with KI and CHNaO2 was significantly more effective in reducing bacterial stained surface of rough titanium implants than air-abrasive powder, diode laser, and plasma cleaning, regardless of the accessibility of the contaminated implant location. Complete bacterial elimination (residual bacteria < 1%) was achieved only for the electrolytic cleaning approaches, irrespectively of the favorable or unfavorable access to implant surface.

Treatment of real aquaculture effluent using bacteria-based bioflocculant produced by Serratia marcescens

Aquaculture effluent contributes to surface water pollution. Coagulation, flocculation, and sedimentation are currently the best practices in aquaculture effluent treatment, and the utilization of chemical coagulants or flocculants is still dominant in assisting the treatment processes. This research aimed to analyze the potential of the bacteria-based bioflocculant produced by Serratia marcescens in treating real aquaculture effluent. S. marcescens was cultivated for 24 h inside tryptic soy broth medium, and the produced bioflocculant was used in raw condition (without extraction). Jar test and one-variable-at-a-time method were used to assess the effect of bioflocculant dosage, and its performance was compared with that of alum, a commonly used coagulant. The bioflocculant produced by S. marcescens worked well with the assistance of CaCl2. The 10% bioflocculant dosage showed a remarkable removal of turbidity and suspended solid (83.95% and 78.82%, respectively) compared with the control (80.98% and 76.99%, respectively). Increasing the bioflocculant dosage had a negative effect on color removal because the bioflocculant solution had a reddish color as a result of prodigiosin secretion by S. marcescens. Zeta potential, particle size distribution, and microscopic analyses revealed that flocculation occurred via the bridging mechanism. The utilization of CaCl2 + bioflocculant showed notable performances in turbidity and suspended solid removal compared with the control reactor while exhibiting a similar efficiency as alum (p < 0.05). Bioflocculant extraction is suggested to be conducted in future research to eliminate its negative effect on the color parameter.

Effects of chlorpyrifos on the metabolic profiling of Bacillus megaterium strain RRB

Many microorganisms have been reported to degrade organic pollutants in the environment and plants, however, the specific information about the effect of organic pollutants on the metabolism of microorganisms is poorly investigated. In the present study, the effect of the pesticide chlorpyrifos on the metabolic profiling of Bacillus megaterium strain RRB was investigated using metabolomics. Our data show that chlorpyrifos acting as an energy source was readily concentrated in the strain RRB from the culture medium. During early cultivation, the shift in energy sources from tryptic soy broth to chlorpyrifos may temporarily cause the strain RRB to enter the starvation stage, where some synthesis-related amino acids and intermediates in the pathways of TCA cycle and pyridoxine metabolism were decreased. The increase of nucleotides and lysine may help the strain RRB cope with the starvation stage. During later cultivation, many metabolites including organic acids, nucleosides and sugar phosphates were gradually accumulated, which indicates that chlorpyrifos could be utilized by the stain RRB to generate metabolites bacteria needed. In addition, arginine acting as a nitrogen-storage amino acid was gradually decreased with later cultivation, suggesting that chlorpyrifos could not provide enough nitrogen for bacteria.

Proposal of a novel selective enrichment broth, NCT-mTSB, for isolation of Escherichia albertii from poultry samples.

Escherichia albertii is an emerging diarrheagenic pathogen causing food- and water-borne infection in humans. However, no selective enrichment broths for E. albertii have ever been reported. In this study, we tested several basal media, selective supplements and culture conditions which enabled selective enrichment of E. albertii. We developed a selective enrichment broth, novobiocin-cefixime-tellurite supplemented modified tryptic soy broth (NCT-mTSB). NCT-mTSB supported the growth of 22 E. albertii strains, while inhibited growth of other Enterobacteriaceae at 37°C, except for Escherichia coli and Shigella spp. Enrichment of E. albertii was improved further by growth at 44°C, a temperature that suppresses growth of several strains of E. coli/Shigella. Combined use of NCT-mTSB with XR-DH-agar, xylose-rhamnose supplemented deoxycholate hydrogen sulphide agar, enabled isolation of E. albertii when at least 1CFU of the bacterium was present per gram of chicken meat. This level of enrichment was superior to those obtained using buffered peptone water, modified-EC broth, or mTSB (with novobiocin). Novobiocin-cefixime-tellurite supplemented modified tryptic soy broth enabled effective enrichment of E. albertii from poultry samples and was helpful for isolation of this bacterium. To our knowledge, this is the first report of selective enrichment of E. albertii from poultry samples.