Non-aureus staphylococci and mammaliicocci (NASM): their role in bovine mastitis and One Health.

Non-aureus staphylococci (NAS) are gaining importance in mastitis and public health, and some NAS have been reclassified as mammaliicocci (NASM). Bovine milk production has a major influence on the world economy, being an essential source of income for small, medium and large producers, and bovine mastitis caused by NASM can cause an economic impact. Mastitis generates financial losses due to reduced revenue, increased veterinary costs and expenses associated with animal slaughter. However, it is also a public health issue involving animal health and welfare, human health and the ecosystem. Furthermore, it is an increasingly common infection caused by NASM, including antimicrobial-resistant strains. Despite all these adverse effects that NASM can cause, some studies also point to its protective role against mastitis. Therefore, this review article addresses the negative and positive aspects that NASM can cause in bovine mastitis, the virulence of the disease and resistance factors that make it difficult to treat and, through the One Health approach, presents a holistic view of how mastitis caused by NASM can affect both animal and human health at one and the same time.

1,25 dihydroxyvitamin D3-mediated effects on bovine innate immunity and on biofilm-forming Staphylococcus spp. isolated from cattle with mastitis.

Mastitis is one the most widespread and serious diseases in dairy cattle. Recurrent and chronic infections are often attributable to certain pathogenicity mechanisms in mastitis-causing pathogens such as Staphylococcus spp. These include growing in biofilm and invading cells, both of which make it possible to resist or evade antimicrobial therapies and the host's immune system. This study tested the effects of active vitamin D3 (i.e., calcitriol or 1,25-dihydroxyvitamin D3) on the internalization and phagocytosis of biofilm-forming Staphylococcus spp. isolated from animals with mastitis. Two established bovine cell lines were used: MAC-T (mammary epithelial cells) and BoMac (macrophages). Calcitriol (0-200 nM) did not affect the viability of MAC-T cells nor that of BoMac cells after 24 and 72 h. Concentrations of 0-100 mM for 24 h upregulated the expression of 24-hydroxylase in MAC-T cells, but did not alter that of VDR. Pre-treatment of the cells with calcitriol for 24 h decreased the internalization of S. aureus V329 into MAC-T cells (0-100 nM), and stimulated the phagocytosis of the same strain and of S. xylosus 4913 (0-10 nM). Calcitriol and two conditioned media, obtained by treating the cells with 25-200 nM of the metabolite for 24 h, were also assessed in terms of their antimicrobial and antibiofilm activity. Neither calcitriol by itself nor the conditioned media affected staphylococcal growth or biofilm formation (0-200 nM for 12 and 24 h, respectively). In contrast, the conditioned media (0-100 nM for 24 h) decreased the biomass of preformed non-aureus staphylococcal biofilms and killed the bacteria within them, without affecting metabolic activity. These effects may be mediated by reactive oxygen species and proteins with antimicrobial and/or antibiofilm activity. In short, calcitriol could make pathogens more accessible to antimicrobial therapies and enhance bacterial clearance by professional phagocytes. Moreover, it may modulate the host's endogenous defenses in the bovine udder and help combat preformed non-aureus staphylococcal biofilms (S. chromogenes 40, S. xylosus 4913, and/or S. haemolyticus 6). The findings confirm calcitriol's potential as an adjuvant to prevent and/or treat intramammary infections caused by Staphylococcus spp., which would in turn contribute to reducing antibiotic use on dairy farms.

The effect of different antibiotic combinations in calcium sulfate cement on the growth of Cutibacterium acnes and Staphylococcus periprosthetic shoulder infection isolates.

BACKGROUND: Periprosthetic joint infections (PJI) of the shoulder are a devastating complication of shoulder arthroplasty and are commonly caused by Staphylococcus and Cutibacterium acnes. Absorbable calcium sulfate (CS) beads are sometimes used for delivering antibiotics in PJI. This study evaluates the in vitro effect of different combinations of gentamicin, vancomycin, and ertapenem in beads made from CS cement on the growth of C acnes and coagulase-negative Staphylococcus (CNS) strains. METHODS: Three strains of C acnes and 5 strains of CNS from clinically proven shoulder PJI were cultured and plated with CS beads containing combinations of vancomycin, gentamicin, and ertapenem. Plates with C acnes were incubated anaerobically while plates with Staphylococcus were incubated aerobically at 37 °C. Zones of inhibition were measured at intervals of 3 and 7 days using a modified Kirby Bauer technique, and beads were moved to plates containing freshly streaked bacteria every seventh day. This process was run in triplicate over the course of 56 days. Statistical analysis was conducted using SPSS v. 28 with repeated measures analysis of variance (ANOVA) and pairwise comparisons with Tukey correction. RESULTS: In experiments with C acnes, beads containing ertapenem + vancomycin and vancomycin alone formed the largest zones of inhibition over time (P < .001). In experiments with Staphylococcus, beads containing vancomycin alone formed the largest zones of inhibition over time for all 5 strains (P < .001). Zones of inhibition were 1.4x larger for C acnes than for Staphylococcus with beads containing vancomycin alone. For both C acnes and Staphylococcus, beads containing ertapenem had the strongest initial effect, preventing all bacterial growth in C acnes and almost all growth for Staphylococcus during the first week but dropping substantially by the second week. Beads containing gentamicin alone consistently created smaller zones of inhibition than beads containing vancomycin alone, with vancomycin producing zones 5.3x larger than gentamicin in C acnes and 1.3x larger in Staphylococcus (P < .001). DISCUSSION: These data suggest that for both C acnes and Staphylococcal species, CS beads impregnated with vancomycin were most effective at producing a robust antibiotic effect. Additionally, ertapenem may be a viable supplement in order to create a more potent initial antibiotic effect but is not as effective as vancomycin when used alone. Gentamicin alone was not effective in maintaining consistent and long-term antibiotic effects. These results indicate that amongst the antibiotics currently commercially available to be used with CS, vancomycin is consistently superior to gentamicin in the setting of C. acnes and CNS.

Anti-staphylococcal activity of soilless cultivated cannabis across the whole vegetation cycle under various nutritional treatments in relation to cannabinoid content.

Antibiotic resistance in staphylococcal strains and its impact on public health and agriculture are global problems. The development of new anti-staphylococcal agents is an effective strategy for addressing the increasing incidence of bacterial resistance. In this study, ethanolic extracts of Cannabis sativa L. made from plant parts harvested during the whole vegetation cycle under various nutritional treatments were assessed for in vitro anti-staphylococcal effects. The results showed that all the cannabis extracts tested exhibited a certain degree of growth inhibition against bacterial strains of Staphylococcus aureus, including antibiotic-resistant and antibiotic-sensitive forms. The highest antibacterial activity of the extracts was observed from the 5th to the 13th week of plant growth across all the nutritional treatments tested, with minimum inhibitory concentrations ranging from 32 to 64 µg/mL. Using HPLC, Δ9-tetrahydrocannabinolic acid (THCA) was identified as the most abundant cannabinoid in the ethanolic extracts. A homolog of THCA, tetrahydrocannabivarinic acid (THCVA), reduced bacterial growth by 74%. These findings suggest that the cannabis extracts tested in this study can be used for the development of new anti-staphylococcal compounds with improved efficacy.

Combination antimicrobial therapy: in vitro synergistic effect of anti-staphylococcal drug oxacillin with antimicrobial peptide nisin against Staphylococcus epidermidis clinical isolates and Staphylococcus aureus biofilms.

The ability of Staphylococcus epidermidis and S. aureus to form strong biofilm on plastic devices makes them the major pathogens associated with device-related infections (DRIs). Biofilm-embedded bacteria are more resistant to antibiotics, making biofilm infections very difficult to effectively treat. Here, we evaluate the in vitro activities of anti-staphylococcal drug oxacillin and antimicrobial peptide nisin, alone and in combination, against methicillin-resistant S. epidermidis (MRSE) clinical isolates and the methicillin-resistant S. aureus ATCC 43,300. The minimum inhibitory concentrations (MIC) and minimum biofilm eradication concentrations (MBEC) of oxacillin and nisin were determined using the microbroth dilution method. The anti-biofilm activities of oxacillin and nisin, alone or in combination, were evaluated. In addition, the effects of antimicrobial agents on the expression of icaA gene were examined by quantitative real-time PCR. MIC values for oxacillin and nisin ranged 4-8 µg/mL and 64-128 µg/mL, respectively. Oxacillin and nisin reduced biofilm biomass in all bacteria in a dose-dependent manner and this inhibitory effect was enhanced with combinatorial treatment. MBEC ranges for oxacillin and nisin were 2048-8192 µg/mL and 2048-4096 µg/mL, respectively. The addition of nisin significantly decreased the oxacillin MBECs from 8- to 32-fold in all bacteria. At the 1× MIC and 1/2× MIC, both oxacillin and nisin decreased significantly the expression of icaA gene in comparison with untreated control. When two antimicrobial agents were combined at 1/2× MIC concentration, the expression of icaA were significantly lower than when were used alone. Nisin/conventional oxacillin combination showed considerable anti-biofilm effects, including inhibition of biofilm formation, eradication of mature biofilm, and down-regulation of biofilm-related genes, proposing its applications for treating or preventing staphylococcal biofilm-associated infections, including device-related infections.

Probing Antibacterial and Anticancer Potential of Selenicereus undatus, Pistacia vera L. and Olea europaea L. against Uropathogens, MCF-7 and A2780 Cancer Cells.

Urinary tract infection is an infectious disease that requires immediate treatment. It can occur in any age group and involves both genders equally. The present study was to check the resistance of some antibiotics and to assess the antibacterial potential of three extracts of three plants against notorious bacteria involved in urinary tract infections. Along with assessing the antibacterial activity of plant extracts, we checked for the anticancer potential of these extracts against the cancer cell lines MCF-7 and A2780. Cancer is the leading cause of mortality in developed countries. Determinations of total flavonoid content, total phenolic content, total alkaloid content, total tannin content, total carotenoid content, and total steroid content were performed. The disk diffusion method was used to analyze the antibacterial activity of plant extracts. Ethanolic extract of Selenicereus undatus showed sensitivity (25-28 mm) against bacteria, whereas chloroform and hexane extracts showed resistance against all bacteria except Staphylococcus (25 mm). Ethanolic extract of Pistacia vera L. showed sensitivity (22-25 mm) against bacteria, whereas chloroform and hexane extracts showed resistance. Ethanolic extract of Olea europaea L. showed sensitivity (8-16 mm) against all bacteria except Staphylococcus, whereas chloroform and hexane extracts showed resistance. Positive controls showed variable zones of inhibition (2-60 mm), and negative control showed 0-1 mm. The antibiotic resistance was much more prominent in the case of hexane and chloroform extracts of all plants, whereas ethanolic extract showed a sensitivity of bacteria against extracts. Both cell lines, MCF-7 and A2780, displayed decreased live cells when treated with plant extracts.

Antibacterial Effect of Ethanolic Extracts of Dodonaea viscosa L. Jacq. and Mammea americana L. against Staphylococci Isolated from Skin Lesions.

Background: The resistance to antibiotics shown by some dermatological pathogenic microorganisms has increased the interest of pharmaceutical and cosmetic industries in developing natural products that possess different biological activities, including antimicrobial effects. Methods: In the present investigation, the antibacterial activity of ethanolic extracts of Dodonaea viscosa aerial part and Mammea americana leaves and seed was evaluated against resistant strains of Staphylococcus isolated from skin lesions and against S. aureus ATCC 25923 (reference strain). Column chromatography (CC) and preparative thin-layer chromatography (PTLC) were used to obtain separate fractions of the seed extract of M. americana. We also determined the antimicrobial resistance of the strains against antibiotics using the agar disc diffusion assay. In addition, phytochemical screening was performed by colorimetric standard techniques. Results: M. americana seed extract showed the highest antibacterial activity with MBC from 2.3 µg/mL to 19.5 µg/mL without differences with gentamicin (p = 0.998). The isolated strain S. epidermidis I showed the highest antimicrobial resistance against the tested antibiotics. PTLC-fractions of M. americana seed extract showed MBC from 3.2 µg/mL to 40.7 µg/mL against S. epidermidis I and S. aureus 25923 (reference), respectively, which suggests a synergistic effect of the secondary metabolites present in the crude ethanolic extract compared to its active PTLC-fractions, where only coumarins and compounds with lactone groups were detected in the phytochemical screening. Conclusion: M. americana seed extract has promising effects that should be considered in further studies as an alternative or adjuvant in treating skin infections caused by staphylococci.

Ecology and resistance to UV light and antibiotics of microbial communities on UV cabins in the dermatology service of a Spanish hospital.

Microorganisms colonize all possible ecological habitats, including those subjected to harsh stressors such as UV radiation. Hospitals, in particular the UV cabins used in phototherapy units, constitute an environment in which microbes are intermittently subjected to UV irradiation. This selective pressure, in addition to the frequent use of antibiotics by patients, may represent a threat in the context of the increasing problem of antimicrobial resistance. In this work, a collection of microorganisms has been established in order to study the microbiota associated to the inner and outer surfaces of UV cabins and to assess their resistance to UV light and the antibiotics frequently used in the Dermatology Service of a Spanish hospital. Our results show that UV cabins harbor a relatively diverse biocenosis dominated by typically UV-resistant microorganisms commonly found in sun-irradiated environments, such as Kocuria, Micrococcus or Deinococcus spp., but also clinically relevant taxa, such as Staphylococcus or Pseudomonas spp. The UV-radiation assays revealed that, although some isolates displayed some resistance, UV is not a major factor shaping the biocenosis living on the cabins, since a similar pool of resistant microorganisms was identified on the external surface of the cabins. Interestingly, some Staphylococcus spp. displayed resistance to one or more antibiotics, although the hospital reported no cases of antibiotic-resistance infections of the patients using the cabins. Finally, no association between UV and antibiotic resistances was found.

THE EFFECT OF RUTA GRAVEOLENS L. ETHANOLIC EXTRACTS ON SKIN ISOLATES OF STAPHYLOCOCCI AND PROPIONIBACTERIUM ACNES.

OBJECTIVE: The aim: To define antimicrobial properties of 50%, 70% and 90% ethanolic extracts of Ruta graveolens L. against macrolide resistant (MLS-resistant) skin isolates of staphylococci and Propionibacterium acnes, and to determine MIC and MBC of investigated extracts. PATIENTS AND METHODS: Materials and methods: Extracts were prepared by the method of maceration. Bacterial cultures were identified by biochemical microtests. Identification of MLS-resistance type was performed by using disc-diffusion method. The MIC and MBC were determined by serial two-fold dilution of ethanolic extracts of Ruta graveolens L. in MHB and HBB for staphylococci and P. acnes, respectively. Bacterial growth in each well was assayed by absorption at 495 nm, using a spectrophotometer SynergyTMHTX S1LFTA (BioTek Instruments, Inc., USA). RESULTS: Results: All ethanolic extracts of garden ruta were active against all staphylococci and P. acnes skin isolates and showed exclusively bactericidal activity (MBC/MIC ratios ranged from 1 to 2) against all investigated strains. 90% extract of Ruta graveolens L. showed better results than 50% and 70% extracts - average MIC and MBC concentations for P. acnes strains were 1.38«0.66 mg/mL and for staphylococcal strains average MIC was 2.1«1.16 mg/mL and MBC - 2.86«1.2 mg/mL. CONCLUSION: Conclusions: 50%, 70% and 90% ethanolic garden ruta extracts showed moderate antibacterial activity against main skin pathogens, responsible for acnes vulgaris development - S. epidermidis, S. aureus and P. acnes. No difference in susceptibility between resistance and sensitive strains of staphylococci and P. acnes indicate that acquired MLS-resistance of investigated skin isolates does not affect on the level of their sensitivity to ruta extracts.

Mupirocin enhances the biofilm formation of Staphylococcus epidermidis in an atlE-dependent manner.

The pathogenicity of Staphylococcus epidermidis is largely attributed to its exceptional ability to form biofilms. Here, we report that mupirocin, an antimicrobial agent widely used for staphylococcal decolonization and anti-infection, strongly stimulates the biofilm formation of S. epidermidis. Although the polysaccharide intercellular adhesin (PIA) production was unaffected, mupirocin significantly facilitated extracellular DNA (eDNA) release by accelerating autolysis, thereby positively triggering cell surface attachment and intercellular agglomeration during biofilm development. Mechanistically, mupirocin regulated the expression of genes encoding for the autolysin AtlE as well as the programmed cell death system CidA-LrgAB. Critically, through gene knockout, we found out that deletion of atlE, but not cidA or lrgA, abolished the enhancement of biofilm formation and eDNA release in response to mupirocin treatment, indicating that atlE is required for this effect. In Triton X-100 induced autolysis assay, mupirocin treated atlE mutant displayed a slower autolysis rate compared with the wild-type strain and complementary strain. Therefore, we concluded that subinhibitory concentrations of mupirocin enhance the biofilm formation of S. epidermidis in an atlE dependent manner. This induction effect could conceivably be responsible for some of the more unfavourable outcomes of infectious diseases.

Antimicrobial activity of α-mangostin against Staphylococcus species from companion animals in vitro and therapeutic potential of α-mangostin in skin diseases caused by S. pseudintermedius.

Antimicrobial resistance in Staphylococcus species from companion animals is becoming increasingly prevalent worldwide. S. pseudintermedius is a leading cause of skin infections in companion animals. α-mangostin (α-MG) exhibits various pharmacological activities, including antimicrobial activity against G (+) bacteria. This study investigated the antimicrobial activity of α-MG against clinical isolates of Staphylococcus species from companion animals and assessed the therapeutic potential of α-MG in skin diseases induced by S. pseudintermedius in a murine model. Furthermore, the action mechanisms of α-MG against S. pseudintermedius were investigated. α-MG exhibited antimicrobial activity against clinical isolates of five different Staphylococcus species from skin diseases of companion animals in vitro, but not G (-) bacteria. α-MG specifically interacted with the major histocompatibility complex II analogous protein (MAP) domain-containing protein located in the cytoplasmic membrane of S. pseudintermedius via hydroxyl groups at C-3 and C-6. Pretreatment of S. pseudintermedius with anti-MAP domain-containing protein polyclonal serum significantly reduced the antimicrobial activity of α-MG. The sub-minimum inhibitory concentration of α-MG differentially regulated 194 genes, especially metabolic pathway and virulence determinants, in S. pseudintermedius. α-MG in pluronic lecithin organogel significantly reduced the bacterial number, partially restored the epidermal barrier, and suppressed the expression of cytokine genes associated with pro-inflammatory, Th1, Th2, and Th17 in skin lesions induced by S. pseudintermedius in a murine model. Thus, α-MG is a potential therapeutic candidate for treating skin diseases caused by Staphylococcus species in companion animals.

In vitro evaluation of multiple antibacterial agents for the treatment of chronic staphylococcal anterior blepharitis.

OBJECTIVE: To evaluate the bactericidal efficacy of several compounds used in the treatment of chronic staphylococcal anterior blepharitis through an in vitro study. MATERIALS AND METHODS: Standard commercial strains of Staphylococcus aureus (SAu) (ATCC 25923 Culti-Loops) and coagulase-negative Staphylococcus (CoNS) (ATCC 12228 Culti-Loops) were cultured. Susceptibility tests were performed to vancomycin 30 µg, netilmicin 30 µg, hypochlorous acid (HOCl) 0.01% (Ocudox™, Brill®), Melaleuca alternifolia leaf oil (MeAl) (Navyblef® Daily Care, NOVAX®) and 1% chlorhexidine digluconate (DGCH) (Cristalmina™, Salvat®) using the agar disk diffusion method (Rosco Neo-Sensitabs®). After 24 h, the induced halos were measured with automatic calipers. The results were analyzed using the EUCAST- and CLSI potency Neo-Sensitabs® guidelines. RESULTS: Vancomycin induced a halo of 22.37 mm and 21.81 mm in SAu and CoNS, respectively. Netilmicin produced halos of 24.45 mm in SAu and 32.49 mm in CoNS. MeAl induced halos of 12.65 mm in SAu and 15.83 mm in CoNS. A 12.11 mm halo was found in SAu and an 18.38 mm halo in CoNS using HOCl. DGCH produced halos of 26.55 mm and 23.12 mm in SAu and CoNS, respectively. CONCLUSION: Netilmicin and vancomycin demonstrated antibiotic activity against both pathogens, so they can be alternative rescue therapies to treat chronic staphylococcal blepharitis. DGCH has efficacy against both comparable to antibiotics, while HOCl and MeAl show less efficacy.

Antimicrobial, Antibiofilm Activities and Synergic Effect of Triterpene 3ß,6ß,16ß-trihydroxyilup-20(29)-ene Isolated from Combretum leprosum Leaves Against Staphylococcus Strains.

Antimicrobial resistance is a natural phenomenon and is becoming a huge global public health problem, since some microorganisms not respond to the treatment of several classes of antibiotics. The objective of the present study was to evaluate the antibacterial, antibiofilm, and synergistic effect of triterpene 3ß,6ß,16ß-trihydroxyilup-20(29)-ene (CLF1) against Staphylococcus aureus and Staphylococcus epidermidis strains. Bacterial susceptibility to CLF1 was evaluated by minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assay. In addition, the effect combined with antibiotics (ampicillin and tetracycline) was verified by the checkerboard method. The biofilms susceptibility was assessed by enumeration of colony-forming units (CFUs) and quantification of total biomass by crystal violet staining. The compound showed bacteriostatic and bactericidal activity against all Staphylococcal strains tested. The synergistic effect with ampicillin was observed only for S. epidermidis strains. Moreover, CLF1 significantly inhibited the biofilm formation and disrupted preformed biofilm of the all strains. Scanning electron microscopy (SEM) images showed changes in the cell morphology and structure of S. aureus ATCC 700698 biofilms (a methicillin-resistant S. aureus strain). Molecular docking simulations showed that CLF1 has a more favorable interaction energy than the antibiotic ampicillin on penicillin-binding protein (PBP) 2a of MRSA, coupled in different regions of the protein. Based on the results obtained, CLF1 proved to be a promising antimicrobial compound against Staphylococcus biofilms.

Electroacupuncture Improves Depression-Like Behavior by Regulating the Abundance of Lactobacillus and Staphylococci in Mice.

BACKGROUND: Growing evidence suggests that gut microbiota can affect depression-like behavior, and electroacupuncture (EA) can regulate the composition and abundance of gut microbiota. At the same time, not a lot of research has been done on how EA affects gut microbiota to depression-like behavior. The objective of this study was to study the associated mechanisms by which EA exerts antidepressant effects by modulating gut microbiota. METHODS: Twenty-four C57BL/6 male mice were randomly divided into three groups, one group (n = 8) was the normal control group (NC). And the other two groups was chronic unpredictable mild stress for modeling + electroacupuncture group (CUMS + EA) (n = 8) and chronic unpredictable mild stress for modeling group (CUMS) (n = 8). Both CUMS and EA groups were subjected to 28 days of CUMS, but only the EA group received an additional 14 days of EA procedure. Behavior tests were used to determine the antidepressant effect of EA. Sequencing of the 16S ribosomal RNA (rRNA) gene was applied to examine alterations in the intestinal microbiome between groups. RESULTS: The findings were compared to those of the NC group, the sucrose preference rate and the total distance of Open Field Test (OFT) in CUMS group decreased, the abundance of Lactobacillus decreased, while the abundance of staphylococci increased. After the intervention of EA, the sucrose preference index and the total distance of OFT increased, the abundance of Lactobacillus increased, while the abundance of staphylococci decreased. CONCLUSIONS: These findings indicated EA may play an antidepressant effect by adjusting the abundance of Lactobacillus and staphylococci.

Antimicrobial agents in small animal dermatology for treating staphylococcal infections.

Abstract: Antibiotic recommendations for treating skin infections have been published many times in the past 30 years. Prior to 2000, the recommendations focused on the use of ß-lactam antibiotics, such as cephalosporins, amoxicillin-clavulanate, or ß-lactamase stable penicillins. These agents are still recommended, and used, for wild-type methicillin-susceptible strains of Staphylococcus spp. However, since the mid-2000s there has been an increase in methicillin-resistant Staphylococcus spp (MRSP). The increase among S pseudintermedius in animals coincided with the increase in methicillin-resistant S aureus that was observed in people near the same time. This increase led veterinarians to reevaluate their approach to treating skin infections, particularly in dogs. Prior antibiotic exposure and hospitalization are identified as risk factors for MRSP. Topical treatments are more often used to treat these infections. Culture and susceptibility testing is performed more often, especially in refractory cases, to identify MRSP. If resistant strains are identified, veterinarians may have to rely on antibiotics that were previously used uncommonly for skin infections, such as chloramphenicol, aminoglycosides, tetracyclines, and human-label antibiotics such as rifampin and linezolid. These drugs carry risks and uncertainties that must be considered before they are routinely prescribed. This article will discuss these concerns and provide veterinarians guidance on the treatment of these skin infections.

Effect of Mauritia flexuosa L. leaf extract on Staphylococcus aureus and Staphylococcus haemolyticus biofilms adhered to stainless steel surface.

Staphylococcus spp. represents the main mastitis agents in ruminants and contaminants of milk due to their expressive capacity to make biofilms. The aims in this study was evaluate evaluated the antimicrobial activity of Mauritia flexuosa L. extracts against Staphylococcus spp. adhered to a stainless steel surface. Two isolates from cows with clinical mastitis were evaluated; one was identified as Staphylococcus aureus, and the other Staphylococcus haemolyticus. Additionally the ATCC 25923 strain, S. aureus from human was evaluated. The chemical profile obtained from gas chromatography revealed the presence of carbohydrates, organic acids, and flavonoids. The minimum bactericidal concentrations of the ethanolic extract (EE) and aqueous extract (AE) were 4.4 and 5.82 mg/mL, respectively. After EE treatment at 4.4 mg/mL for 2.5 min, total removal of mature biofilms grown on stainless steel coupons was observed (reduction by 3.85-4.81 log units). This extract from M. flexuosa shows potential as an effective sanitizer and may represent a natural alternative against Staphylococcus spp.

Actividad antimicrobiana de extractos de plantas frente a Staphylococcus aislados de pacientes con conjuntivitis bacteriana / Antimicrobial Activity of Plant Extracts against Isolated Staphylococcus Infection in Patients with Bacterial Conjunctivitis / Atividade antimicrobiana de extratos vegetais contra Staphylococcus isolados de pacientes com conjuntivite bacteriana

Staphylococcus aureus y Staphylococcus epidermidis son los principales agentes etiológicos de las conjuntivitis bacterianas, que al tratarse con antibióticos de manera empírica, incrementan la resistencia antimicrobiana después de exposiciones repetidas. Se están buscando alternativas naturales para el tratamiento de infecciones bacterianas autolimitadas de la conjuntiva. Objetivo: determinar la actividad antimicrobiana de ocho extractos de las plantas frente a bacterias aisladas de pacientes con conjuntivitis bacterianas. Materiales y métodos: se tomaron muestras de 15 pacientes con conjuntivitis bacterianas. Se cultivaron en agar sangre y chocolate durante 24 h a 37 °C y se identificaron mediante el sistema automatizado vitek y pruebas de susceptibilidad antimicrobiana por el método de Kirby-Bauer. A cada aislamiento identificado con el género Staphylococcus se le evaluó su susceptibilidad frente a siete extractos: Ocimum basilicum, Sambucus nigra L., Delphinium elatum, Calendula officinalis, Bixa ore-llana (parte aérea y fruto independiente), Clinopodium brownei y Laurus nobilis, con un uso tradicional reportado para el tratamiento de infecciones oculares. Resultados: las bacterias aisladas con más frecuencia fueron S. epidermidis, S. hominis y S. aureus, las cuales presentaron resistencia antimicrobiana a oxacilina, tetraciclinas y eritromicina. Todos los aislamientos fueron inhibidos por los extractos de O. basilicum (cmi: >0.9 mg/mL) y L. nobilis (cmi: hasta 15 mg/mL). Conclusión: los extractos de C. officinalis y D. elatum tuvieron actividad antimicrobiana solo frente a los aislados con mayor sensibilidad antimi-crobiana. Los extractos etanólicos de O. basilicum y L. nobilis pueden ser una alternativa de tratamiento de las infecciones de la conjuntiva.

Staphylococcus aureus and Staphylococcus epidermidis are the primary etiological agents of bacterial conjunctivitis which are empirically treated with antibiotics. This results in an increase in antimicrobial resistance due to repeated exposure. Currently, natural treatment alternatives are being sought for self-limited bacterial infections of the conjunctiva. Objective: To determine the antimicrobial activity of eight extracts from Colombian plants against bacteria isolated from patients with bacterial conjunctivitis. Materials and methods: Samples were taken from 15 patients with bacterial conjunctivitis which were grown on blood and chocolate agar for 24 h at 37 °C. These samples were identified by the vitek automated system and antimicrobial susceptibility tests by the Kirby Bauer method. Each isolate identified with the genus Staphylococcus was evaluated for susceptibility to the following eight plant extracts of seven plant: Ocimum basilicum (basil), Sambucus nigra L. (elderberry), Delphinium elatum(belladonna), Calendula officinalis (marigold), Bixa orellana (annatto) (aerial part and independent fruit), Clinopodium brownei (pennyroyal), and Laurus nobilis (laurel), with traditional use previously reported for treating eye infections. Results: The most frequently isolated bacteria were S. epidermidis, S. hominis, and S. aureus, which exhibited antimicrobial resistance mainly to oxacillin, tetracyclines, and erythromycin. All isolates were inhibited by O. basilicum extracts (mic > 0.9 mg/mL) and L. nobilis (mic < 15 mg/mL). Conclusion: The extracts of C. officinalis y D. elatum showed antimicrobial activity only against isolates with higher antimicrobial sensitivity. Ethanolic extracts of O. basilicum y L. nobilis can be used as an alternative treatment for infections of the anterior segment of the eye.

Staphylococcus aureus e Staphylococcus epidermidis são os principais agentes etiológicos da conjuntivite bacteriana, estes são tratados empiricamente com antibióticos, causando aumento da resistência antimicrobiana após repetidas exposições aos mesmos. Atualmente, estão sendo estudadas alternativas naturais para o tratamento de infecções bacterianas autolimitadas da conjuntiva. Objetivo: determinar a atividade antimicrobiana de oito extratos de sete vegetais contra bactérias isoladas de pacientes com conjuntivite bacteriana. Materiais e métodos: foram retiradas amostras de 15 pacientes com conjuntivite bacteriana. As amostras foram cultivadas em ágar sangue e ágar chocolate por 24 horas a 37°C e os isolados foram identificados pelo sistema automatizado vitek, além de testes de susce-tibilidade antimicrobiana pelo método Kirby Bauer. Cada isolado identificado como sendo pertencente ao gênero Staphylococcus foi avaliado quanto à suscetibilidade a oito extratos vegetais: Ocimum basili-cum (manjericão), Sambucus nigra L. (sabugueiro), Delphinium elatum (belladona), Calendula officinalis(calêndula), Bixa orellana (urucum; parte aérea e fruto independente), Clinopodium brownei (poejo) e Laurus nobilis (louro), anteriormente relatados como uso tradicional para o tratamento de infecções ocu-lares. Resultados: as bactérias mais frequentemente isoladas foram S. epidermidis, S. hominis e S. aureus, que apresentaram resistência antimicrobiana principalmente à oxacilina, tetraciclinas e eritromicina. Todos os isolados foram inibidos por extratos de O. basilicum (cim: >0,9 mg/mL) e L. nobilis (cim: até 15 mg/mL). Conclusão: os extratos de C. officinalis e D. elatum apresentaram atividade antimicrobiana apenas contra os isolados com maior sensibilidade antimicrobiana. Os extratos etanólicos de O. basilicum e L. nobilis podem ser uma alternativa de tratamento para infecções conjuntivais.

Synthesis and Characterization of Tween-20 Capped Biosynthesized Silver Nanoparticles for Anticancer and Antimicrobial Property.

The Vitrus vinifera fruit extract was used to make silver nanoparticles (AgNPs) utilizing a green chemical technique. The biosynthesized Tween-20/Vitrus vinifera-AgNPs were observed by UV-Vis spectrophotometry. Fourier transform infrared spectroscopy, scanning transmission electron microscopy, selected area electron diffraction, and energy-dispersive X-ray spectroscopy were used to characterize the physiochemical properties. The spherical form of AgNPs was confirmed by transmission electron microscopy. The peaks in the Tween-20/Vitrus vinifera-AgNPs have an average crystallite size that is found to be 46 nm according to powder X-ray diffraction examination. Biosynthesized AgNPs had a significant effect on bone osteosarcoma MG63 cells with 55% inhibition, respectively, using MTT assay. The effective dangerous concentration of Tween-20/Vitrus vinifera with AgNP nanoparticles was less harmful to MG63 cells. The results of antibacterial activity showed that Tween-20/Vitrus vinifera-AgNPs effectively inhibited Eggerthella lenta and Staphylococcus epidermis bacteria.

Dispersion and persistence of antimicrobial resistance genes among Staphylococcus spp. and Mammaliicoccus spp. isolated along a swine manure treatment plant.

Staphylococcus spp. and Mammaliicoccus spp. colonize the skin and mucosa of humans and other animals and are responsible for several opportunistic infections. Staphylococci antibiotic resistance may be present in the environment due to the spread of treated and untreated manure from the livestock industry due to antibiotic use to disease control or growth promoter. In this work, we analyzed the species distribution and antimicrobial susceptibility of Staphylococcus and Mammaliicoccus species along different sites of a swine manure treatment plant from Southeastern Brazil. Bacterial colonies were obtained on mannitol salt agar, selected after catalase test and Gram staining, and finally identified by mass spectrometry and sequencing of the tuf gene. According to the results, S.cohnii and S. simulans were the most prevalent species. Antibiotic resistance test revealed that several strains were resistant to multiple drugs, with high levels of chloramphenicol resistance (98%), followed by erythromycin (79%), tetracycline (73%), gentamicin (46%), ciprofloxacin (42%), cefoxitin (18%), sulfamethoxazole + trimethoprim (12%), and linezolid (4%). In addition, gene detection by PCR showed that all strains carried at least 2 resistance genes and one of them carried all 11 genes investigated. Using the GTG5-PCR approach, a high genetic similarity was observed between some strains that were isolated from different points of the treatment plant. Although some were seemingly identical, differences in their resistance phenotype and genotype suggest horizontal gene transfer. The presence of resistant bacteria and resistance genes along the treatment system highlights the potential risk of contamination by people in direct contact with these animals and the soil since the effluent is used as a biofertilizer in the surrounding environment.