While home chlorhexidine washes prior to shoulder surgery lower skin loads of most bacteria, they are not effective against Cutibacterium (Propionibacterium).

PURPOSE: Chlorhexidine showers prior to shoulder arthroplasty are commonly recommended by surgeons to lower the risk of periprosthetic infection; however, the effectiveness of these washes in eliminating bacteria from the skin of the shoulder has not been thoroughly evaluated. The objective of this study was to determine the degree to which pre-operative chlorhexidine washes effectively eliminate bacteria from the epidermal skin surface and from the dermis freshly incised during shoulder arthroplasty. METHODS: Around 66 patients undergoing primary shoulder arthroplasty were instructed to shower with chlorhexidine before surgery. Each patient had three skin swabs: (1) the epidermis at a pre-operative clinic appointment, (2) the epidermis at surgery after home chlorhexidine showers but prior to skin preparation, and (3) the dermis after incision of the prepared skin. The bacterial loads of Cutibacterium and other bacterial types from each swab were compared to determine whether the showers were effective in altering the bacterial loads. RESULTS: Chlorhexidine washes were effective in reducing the skin load of other bacterial species (p < 0.005), but they did not decrease the skin load of Cutibacterium (p = 0.585). CONCLUSIONS: Pre-operative skin showers with chlorhexidine were not effective in reducing the load of Cutibacterium on the skin of patients having shoulder arthroplasty. Since Cutibacterium is responsible for the highest percentage of shoulder periprosthetic infections, research is needed to identify more effective means of removing these bacteria from the surgical field.

0.01% Hypochlorous Acid as an Alternative Skin Antiseptic: An In Vitro Comparison.

OBJECTIVE: Compare the in vitro efficacy of hypochlorous acid 0.01% (HA), povidone iodine 5% (PI), chlorhexidine gluconate 4% (CHG), and isopropyl alcohol 70% (IPA) against common skin microorganisms. MATERIALS AND METHODS: Time-kill studies were conducted against methicillin-susceptible Staphylococcus aureus (MSSA) and Staphylococcus epidermidis (MSSE), methicillin-resistant S. aureus (MRSA) and S. epidermidis (MRSE), Candida albicans, Corynebacterium species (striatum and amycolatum), Propionibacterium acnes, Pseudomonas aeruginosa, Streptococcus pyogenes, Staphylococcus capitis, and Staphylococcus xylosus. RESULTS: Methicillin-resistant S. aureus: Bactericidal effect was immediate for HA and IPA. For PI and CHG, the effect occurred at 1 and 10 minutes, respectively. Methicillin-resistant S. epidermidis: Hypochlorous acid, IPA, and PI had immediate bactericidal effects, whereas CHG required 1 minute. Methicillin-susceptible Staphylococcus aureus: All agents had bactericidal effects at 1 minute. C. species, S. pyogenes, P. aeruginosa, and P. acnes: All antiseptics demonstrated immediate bactericidal effects. Methicillin-susceptible Staphylococcus epidermidis and S. capitis: Hypochlorous acid and IPA had immediate effect, whereas PI and CHG required 1 minute. C. albicans: Hypochlorous acid, IPA, and PI were immediately bactericidal, whereas CHG required 1 minute. S. xylosus: Hypochlorous acid and CHG were immediately bactericidal, whereas IPA and PI required 1 and 2 minutes, respectively. CONCLUSION: In vitro studies of HA 0.01% were observed to have equal or more efficacious antiseptic properties compared with IPA, CHG, and PI. Future studies will be needed to investigate its role in periocular use.

Applicability of ribosome engineering to vitamin B12 production by Propionibacterium shermanii.

Ribosome engineering has been widely utilized for strain improvement, especially for the activation of bacterial secondary metabolism. This study assessed ribosome engineering technology to modulate primary metabolism, taking vitamin B12 production as a representative example. The introduction into Propionibacterium shermanii of mutations conferring resistance to rifampicin, gentamicin, and erythromycin, respectively, increased per cell production (µg/L/OD600) of vitamin B12 5.2-fold, although net production (µg/L) was unchanged, as the cell mass of the mutants was reduced. Real-time qPCR analysis demonstrated that the genes involved in vitamin B12 fermentation by P. shermanii were activated at the transcriptional level in the drug-resistant mutants, providing a mechanism for the higher yields of vitamin B12 by the mutants. These results demonstrate the efficacy of ribosome engineering for the production of not only secondary metabolites but of industrially important primary metabolites.

Dynamic interactions between prophages induce lysis in Propionibacterium acnes.

Progress in next-generation sequencing technologies has facilitated investigations into microbial dynamics. An important bacterium in the dairy industry is Propionibacterium freudenreichii, which is exploited to manufacture Swiss cheeses. A healthy culture of these bacteria ensures a consistent cheese with formed 'eyes' and pleasant flavour profile, and the investigation of prophages and their interactions with these bacteria could assist in the maintenance of the standard of this food product. Two bacteriophages, termed PFR1 and PFR2, were chemically induced using mitomycin C from two different dairy strains of P. freudenreichii. Both phages have identical genomes; however, PFR2 was found to contain an insertion sequence, IS204. Host range characterisation showed that PFR1 was able to form plaques on a wild type Propionibacterium acnes strain, whereas PFR2 could not. The lytic plaques observed on P. acnes were a result of PFR1 inducing the lytic cycle of a pseudolysogenic phage in P. acnes. Further investigation revealed that both PFR1 and PFR2 could infect P. acnes but not replicate. This study demonstrates the dynamic interactions between phages, which may alter their lytic capacity under certain conditions. To our knowledge, this is the first report of two phages interacting to kill their host.

Clinical characteristics and antimicrobial susceptibilities of anaerobic bacteremia in an acute care hospital.

This study investigated the clinical features of anaerobic bacteraemia in an acute-care hospital, and evaluated the antimicrobial susceptibility of these isolates to commonly available antibiotics. Microbiological and epidemiological data from 2009 to 2011were extracted from the laboratory information system and electronic medical records. One hundred and eleven unique patient episodes consisting of 116 anaerobic isolates were selected for clinical review and antibiotic susceptibility testing. Susceptibilities to amoxicillin-clavulanate, clindamycin, imipenem, metronidazole, moxifloxacin, penicillin and piperacillin-tazobactam were performed using Etest strips with categorical interpretations according to current CLSI breakpoints. Metronidazole-resistant and carbapenem-resistant anaerobic Gram-negative bacilli were screened for the nim and cfiA genes. Clinical data was obtained retrospectively from electronic medical records. During the 3 year period, Bacteroides fragilis group (41%), Clostridium species (14%), Propionibacterium species (9%) and Fusobacterium species (6%) were the most commonly isolated anaerobes. Patients with anaerobic bacteraemia that were included in the study were predominantly above 60 years of age, with community-acquired infections. The most commonly used empiric antibiotic therapies were beta-lactam/beta-lactamase inhibitor combinations (44%) and metronidazole (10%). The crude mortality was 25%, and appropriate initial antibiotic therapy was not significantly associated with improved survival. Intra-abdominal infections (39%) and soft-tissue infections (33%) accounted for nearly three-quarters of all bacteraemia. Antibiotics with the best anaerobic activity were imipenem, piperacillin-tazobactam, amoxicillin-clavulanate and metronidazole, with in-vitro susceptibility rates of 95%, 95%, 94% and 92% respectively. Susceptibilities to penicillin (31%), clindamycin (60%) and moxifloxacin (84%) were more variable. Two multidrug-resistant isolates of Bacteroides species were positive for nim and cfiA genes respectively, while another two imipenem-resistant Fusobacterium species were negative for cfiA genes. This study demonstrated that anaerobic bacteraemia in our patient population was predominantly associated with intra-abdominal and soft-tissue infections. Overall antibiotic resistance was high for penicillin and clindamycin, and the presence of emerging resistance to carbapenems and metronidazole warrants further monitoring.

Immunogenic inhibition of prominent ruminal bacteria as a means to reduce lipolysis and biohydrogenation activity in vitro.

Lipolysis and biohydrogenation in ruminal animals promote the accumulation of saturated fatty acids in their meat and milk. Antibodies were generated against key ruminal lipase contributors Anaerovibrio lipolyticus, Butyrivibrio fibrisolvens, Propionibacterium avidum and acnes. An anti-Pseudomonas lipase antibody was generated to determine if an antibody against a purified protein would be more effective. Each bacterium was cultured and assayed without or with increasing levels of each antibody. Butyrivibrio fibrisolvens H17C also participates in biohydrogenation and therefore the antibody was tested to determine if it could effectively reduce biohydrogenation. Butyrivibrio fibrisolvens was assayed without and with the anti-B. fibrisolvens antibody and linoleic or α-linolenic acid. All antibodies were effective at reducing lipolysis with the anti-Pseudomonas lipase averaging a 78% reduction. The anti-B. fibrisolvens showed a tendency for a reduction (P=0.0713) in biohydrogenation products of α-linolenic acid. Results demonstrate that lipolysis and biohydrogenation can be immunologically inhibited in vitro.

Antimicrobial Susceptibility of Microorganisms Isolated from Periapical Periodontitis Lesions.

Periapical periodontitis usually results from microbial infection, with these microorganisms occasionally migrating to the root canal, which can lead to further, potentially life-threatening, complications. Here, the susceptibility of 27 bacterial strains to various antimicrobial agents was evaluated. These strains comprised 13 species; 16 of the strains were clinical isolates from periapical lesions. Each strain was inoculated onto blood agar plates containing one of the antimicrobial agents. The plates were incubated anaerobically at 37°C for 96 hr and the minimal inhibitory concentrations (MICs) determined. Ten strains required an MIC of 32 µg/ml or greater for amoxicillin, 6 for cefmetazole, and 5 for cefcapene among ß-lactam antibiotics; 8 strains required an MIC of 32 µg/ml or greater for clindamycin, 4 for azithromycin, and 11 for clarithromycin among macrolide antibiotics; 3 strains required an MIC of 32 µg/ml or greater for ciprofloxacin and 2 for ofloxacin among fluoroquinolones. The effect of cefcapene on 5 strains was evaluated after biofilm formation to investigate the relationship between biofilm formation and susceptibility. All strains showed a decrease in susceptibility after biofilm formation. The results revealed that several antimicrobial agents commonly used in a clinical setting, including amoxicillin, cefmetazole, and clindamycin, are potentially effective in the treatment of orofacial odontogenic infections. The development of resistant strains, however, means that this can no longer be guaranteed. In addition, azithromycin, ciprofloxacin, and ofloxacin were more effective than the 3 ß-lactam antibiotics tested. These results suggest that sensitivity testing is needed if odontogenic infections are to be treated safely and effectively.

Improved production of propionic acid driven by hydrolyzed liquid containing high concentration of l-lactic acid from co-fermentation of food waste and sludge.

This study investigated the feasibility of improved production propionic acid-enriched volatile fatty acid (VFA) from high concentration (Cs) of food waste and waste activated sludge (WAS) via lactic acid pathway by using of Propionibacterium acidipropionici. It was observed that production of l-lactate overwhelmed to d-lactate at first stage, which improved from 3.21 to 35.45gCOD/L with increase of substrate Cs. However, kinetic model analysis indicated that P. acidipropionici growth rate µmax was decreased with increase of l-lactate concentration, which explained second stage free cell fermentation of propionic acid was inhibited when fed by first stage liquid from R-40, R-55 and R-70. Then, the fibrous bed bioreactor was employed to eliminate the feed inhibition. The maximal percentage of propionic acid (68.3%) and production (16.31gCOD/L) was obtained by feeding liquid of R-55, which was improved by 3.33 folds compared to the free cell fermentation.

Antimicrobial activities of ozenoxacin against isolates of propionibacteria and staphylococci from Japanese patients with acne vulgaris.

Ozenoxacin, a novel non-fluorinated topical quinolone, was assessed for in vitro antimicrobial activity against clinical isolates of propionibacteria and staphylococci according to the broth microdilution method recommended by the Clinical and Laboratory Standards Institute. The isolates used in this study were collected from Japanese patients with acne vulgaris during a period from 2012 to 2013. The MIC90s of ozenoxacin against Propionibacterium acnes (n=266), Propionibacterium granulosum (n=10), Staphylococcus aureus (n=23), Staphylococcus epidermidis (n=229) and other coagulase-negative staphylococci (n=82) were ≤0.06, ≤0.06, ≤0.06, 0.125 and ≤0.06 µg ml-1, respectively. The antimicrobial activity of ozenoxacin against the clinical isolates of propionibacteria and staphylococci was greater than that of five reference antimicrobial agents which have been used for the treatment of acne vulgaris. The MICs of ozenoxacin were correlated with those of nadifloxacin in P. acnes and S. epidermidis isolates. However, the MICs of ozenoxacin were 0.25-0.5 µg ml-1 and 0.5-8 µg ml-1 against nadifloxacin-resistant P. acnes (MIC: ≥8 µg ml-1; n=8) and S. epidermidis (MIC: ≥64 µg ml-1; n=10), respectively. These results indicated the potent antimicrobial activity against P. acnes and S. epidermidis isolates resistant to nadifloxacin. Topical ozenoxacin could represent an alternative therapeutic drug for acne vulgaris based on its potent antimicrobial activity against the isolates of propionibacteria and staphylococci from acne patients.

Treatment of prosthetic joint infections due to Propionibacterium. Similar results in 60 patients treated with and without rifampicin.

BACKGROUND AND PURPOSE: Currently, Propionibacterium is frequently recognized as a causative microorganism of prosthetic joint infection (PJI). We assessed treatment success at 1- and 2-year follow-up after treatment of Propionibacterium-associated PJI of the shoulder, hip, and knee. Furthermore, we attempted to determine whether postoperative treatment with rifampicin is favorable. PATIENTS AND METHODS: We conducted a retrospective cohort study in which we included patients with a primary or revision joint arthroplasty of the shoulder, hip, or knee who were diagnosed with a Propionibacterium-associated PJI between November 2008 and February 2013 and who had been followed up for at least 1 year. RESULTS: We identified 60 patients with a Propionibacterium-associated PJI with a median duration of 21 (0.1-49) months until the occurrence of treatment failure. 39 patients received rifampicin combination therapy, with a success rate of 93% (95% CI: 83-97) after 1 year and 86% (CI: 71-93) after 2 years. The success rate was similar in patients who were treated with rifampicin and those who were not. INTERPRETATION: Propionibacterium-associated PJI treated with surgery in combination with long-term antibiotic administration had a successful outcome at 1- and 2-year follow-up irrespective of whether the patient was treated with rifampicin. Prospective studies are needed to determine whether the use of rifampicin is beneficial in the treatment of Propionibacterium-associated PJI.

Two Cases of Urinary Tract Infection Caused by Propionimicrobium lymphophilum.

The first case reports involving Propionimicrobium lymphophilum, a rarely encountered anaerobic Gram-positive non-spore-forming rod, are presented here as urinary tract infections. Initial detection of these bacteria required urine Gram stains. Comparison of the type strain to the two isolates by various methods is depicted and includes antimicrobial susceptibility data.

Screening of Propionibacterium spp. for potential probiotic properties.

The main topic of this paper is the evaluation of adhesion of propionibacteria to IPEC-J2 cells and the survival at pH 2.5 and with 0.3% bile salts added, bioactivity towards pathogens and antibiotic resistance of Propionibacterium freudenreichii subsp. shermanii, Propionibacterium jensenii, Propionibacterium acidipropionici and Propionibacterium thoenii. Adhesion to IPEC-J2 cell lines was ca. 25-35% and significantly increased with CaCl2. Moreover, propionibacteria showed a reduction of cell count of ca. 0.5% at pH 2.5 after 3 h, whereas cell count increased after 24 h with bile salts; finally, they significantly inhibited Escherichia coli O157:H7.

Antimicrobial Activity of Pomegranate and Green Tea Extract on Propionibacterium Acnes, Propionibacterium Granulosum, Staphylococcus Aureus and Staphylococcus Epidermidis.

We used pomegranate extract (POMx), pomegranate juice (POM juice) and green tea extract (GT) to establish in vitro activities against bacteria implicated in the pathogenesis of acne. Minimum inhibitory concentrations (MIC) of 94 Propionibacterium acnes, Propionibacterium granulosum, Staphylococcus aureus, and Staphylococcus epidermidis strains were determined by Clinical and Laboratory Standards Institute-approved agar dilution technique. Total phenolics content of the phytochemicals was determined using the Folin-Ciocalteu method and the polyphenol composition by HPLC. Bacteria were identified by 16S rRNA sequence analysis. GT MIC of 400 µg/ml or less was obtained for 98% of the strains tested. 64% of P. acnes strains had POMx MICs at 50 µg/ml whereas 36% had MIC >400 µg/ml. POMx, POM juice, and GT showed inhibitory activity against all the P. granulosum strains at ≤100 µg/ml. POMx and GT inhibited all the S. aureus strains at 400 µg/ml or below, and POM juice had an MIC of 200 µg/ml against 17 S. aureus strains. POMx inhibited S. epidermidis strains at 25 µg/ml, whereas POM juice MICs were ≥200 µg/ml. The antibacterial properties of POMx and GT on the most common bacteria associated with the development and progression of acne suggest that these extracts may offer a better preventative/therapeutic regimen with fewer side effects than those currently available.

Effects of carbon dioxide on cell growth and propionic acid production from glycerol and glucose by Propionibacterium acidipropionici.

The effects of CO2 on propionic acid production and cell growth in glycerol or glucose fermentation were investigated in this study. In glycerol fermentation, the volumetric productivity of propionic acid with CO2 supplementation reached 2.94g/L/day, compared to 1.56g/L/day without CO2. The cell growth using glycerol was also significantly enhanced with CO2. In addition, the yield and productivity of succinate, the main intermediate in Wood-Werkman cycle, increased 81% and 280%, respectively; consistent with the increased activities of pyruvate carboxylase and propionyl CoA transferase, two key enzymes in the Wood-Werkman cycle. However, in glucose fermentation CO2 had minimal effect on propionic acid production and cell growth. The carbon flux distributions using glycerol or glucose were also analyzed using a stoichiometric metabolic model. The calculated maintenance coefficient (mATP) increased 100%, which may explain the increase in the productivity of propionic acid in glycerol fermentation with CO2 supplement.

Improved propionic acid and 5,6-dimethylbenzimidazole control strategy for vitamin B12 fermentation by Propionibacterium freudenreichii.

An efficient fermentation-strengthening approach was developed to improve the anaerobic production of vitamin B12 by cultivation process optimization with Propionibacterium freudenreichii. The effects of the byproduct propionic acid and the precursor 5,6-dimethylbenzimidazole (DMB) on vitamin B12 biosynthesis were investigated. Byproduct inhibition experiments showed that maintaining propionic acid concentration in broth below 10-20 g/L in the early stage and 20-30 g/L in the late stage can efficiently improve vitamin B12 biosynthesis. Batch fermentation indicated the occurrence of feed-back inhibition in intracellular intermediate biosynthesis. In addition, the incorporation of the precursor DMB depended on the fermentation level of the vitamin B12 intermediate. High vitamin B12 concentration (58.8 mg/L) and production (0.37 mg/g) were obtained with an expanded bed adsorption bioreactor by using the propionic acid and DMB control method. The optimum concentration and production of 59.5 and 0.59 mg/L h for vitamin B12 production were respectively achieved after five continuous batches.

Antibiotic resistance and capacity for biofilm formation of different bacteria isolated from endodontic infections associated with root-filled teeth.

INTRODUCTION: To date, a variety of microbial species have been isolated from endodontic infections. However, endodontic clinical bacterial isolates have not been sufficiently characterized with regard to their capacity for antibiotic resistance and biofilm formation. In this study, antibiotic resistance and biofilm formation of 47 different aerobic and anaerobic bacterial isolates, belonging to 32 different species previously isolated from infected filled root canals, were studied. METHODS: Antibiotic sensitivity to 11 antibiotics including penicillin G, amoxicillin, clindamycin, gentamicin, vancomycin, tetracycline, doxycycline, fosfomycin, rifampicin, ciprofloxacin, and moxifloxacin was tested using the standardized Etest method (Bio Merieux, Marcy-1'Etoile, France). The antibiotic sensitivity of 4 control strains was also estimated in parallel. Additionally, the capacity to form biofilms was quantified using the microtiter plate test. RESULTS: Different aerobic and anaerobic bacterial species were either resistant against a number of antibiotics or showed high minimal inhibitory concentrations against clinically relevant antibiotics. Five aerobic and 2 anaerobic isolates, including Enterococcus faecalis, Streptococcus mutans, Lactobacillus fermentum, Actinomyces naeslundii, Actinomyces viscosus, Prevotella buccae, and Propionibacterium acidifaciens, were characterized as being high biofilm producers, whereas 8 aerobic and 3 anaerobic isolates were found to be moderate biofilm producers. Most isolates with resistance or markedly high minimal inhibitory concentration values were also either moderate biofilm producers or high biofilm producers. CONCLUSIONS: These results suggest that the clinical significance of endodontic infections could include that they serve as a reservoir for antibiotic resistance. Furthermore, endodontic treatment should consider the adhesion and biofilm formation by a variety of bacteria.

Activity of ceftolozane-tazobactam against a broad spectrum of recent clinical anaerobic isolates.

We evaluated in vitro activity of ceftolozane-tazobactam (TOL-TAZ), formerly CXA-201, against recent clinical anaerobic isolates with emphasis on the Bacteroides fragilis group. Ceftolozane-tazobactam showed good activity against B. fragilis species and intermediate to limited activity against other species of Bacteroides. Ceftolozane-tazobactam showed very good activity against Prevotella spp., Fusobacterium spp., and Propionibacterium spp., varying activities against Gram-positive cocci, and limited activity against Clostridium spp.