Combination Of Gentamicin Research Articles

Enhancement of bactericidal effects of bacteriophage and gentamicin combination regimen against Staphylococcus aureus and Pseudomonas aeruginosa strains in a mice diabetic wound model.

Diabetic patients are more susceptible to developing wound infections resulting in poor and delayed wound healing. Bacteriophages, the viruses that target-specific bacteria, can be used as an alternative to antibiotics to eliminate drug-resistant bacterial infections. Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) are among the most frequently identified pathogens in diabetic foot ulcers (DFUs). The aim of this study was assessment of bacteriophage and gentamicin combination effects on bacterial isolates from DFU infections. Specific bacteriophages were collected from sewage and animal feces samples and the phages were enriched using S. aureus and P. aeruginosa cultures. The lytic potential of phage isolates was assessed by the clarity of plaques. We isolated and characterized four lytic phages: Stp2, Psp1, Stp1, and Psp2. The phage cocktail was optimized and investigated in vitro. We also assessed the effects of topical bacteriophage cocktail gel on animal models of DFU. Results revealed that the phage cocktail significantly reduced the mortality rate in diabetic infected mice. We determined that treatment with bacteriophage cocktail effectively decreased bacterial colony counts and improved wound healing in S. aureus and P. aeruginosa infections, especially when administrated concomitantly with gentamicin. The application of complementary therapy using a phage cocktail and gentamicin, could offer an attractive approach for the treatment of wound diabetic bacterial infections.

Antibiotic prophylaxis and hospitalization of horses subjected to median laparotomy: gut microbiota trajectories and abundance increase of Escherichia.

Horse clinics are hotspots for the accumulation and spread of clinically relevant and zoonotic multidrug-resistant bacteria, including extended-spectrum β-lactamase producing (ESBL) Enterobacterales. Although median laparotomy in cases of acute equine colic is a frequently performed surgical intervention, knowledge about the effects of peri-operative antibiotic prophylaxis (PAP) based on a combination of penicillin and gentamicin on the gut microbiota is limited. We collected fecal samples of horses from a non-hospitalized control group (CG) and from horses receiving either a pre-surgical single-shot (SSG) or a peri-operative 5-day (5DG) course of PAP. To assess differences between the two PAP regimens and the CG, all samples obtained at hospital admission (t0), on days three (t1) and 10 (t2) after surgery, were screened for ESBL-producing Enterobacterales and subjected to 16S rRNA V1-V2 gene sequencing. We included 48 samples in the SSG (n = 16 horses), 45 in the 5DG (n = 15), and 20 in the CG (for t0 and t1, n = 10). Two samples of equine patients receiving antibiotic prophylaxis (6.5%) were positive for ESBL-producing Enterobacterales at t0, while this rate increased to 67% at t1 and decreased only slightly at t2 (61%). Shannon diversity index (SDI) was used to evaluate alpha-diversity changes, revealing there was no significant difference between horses suffering from acute colic (5DG, SDImean of 5.90, SSG, SDImean of 6.17) when compared to the CG (SDImean of 6.53) at t0. Alpha-diversity decreased significantly in both PAP groups at t1, while at t2 the onset of microbiome recovery was noticed. Although we did not identify a significant SDImean difference with respect to PAP duration, the community structure (beta-diversity) was considerably restricted in samples of the 5DG at t1, most likely due to the ongoing administration of antibiotics. An increased abundance of Enterobacteriaceae, especially Escherichia, was noted for both study groups at t1. Colic surgery and PAP drive the equine gut microbiome towards dysbiosis and reduced biodiversity that is accompanied by an increase of samples positive for ESBL-producing Enterobacterales. Further studies are needed to reveal important factors promoting the increase and residency of ESBL-producing Enterobacterales among hospitalized horses.

Progressive ulcerative keratitis in dogs in the United Kingdom: Microbial isolates, antimicrobial sensitivity, and resistance patterns.

The objective of the study was to identify bacterial pathogens and their antimicrobial sensitivity profile associated with cases of canine progressive ulcerative keratitis. Analysis of microbial culture and sensitivity results from dogs with progressive ulcerative keratitis presenting to a UK referral practice between December 2018 and August 2020. Positive bacterial cultures were obtained from 80/148 (54%) of the canine ulcers sampled with 99 bacterial isolates cultured. Streptococcus canis (n = 29), Pseudomonas aeruginosa (n = 19), and Staphylococcus pseudintermedius (n = 16) were the most common isolates. Pseudomonas aeruginosa was more likely to be isolated whether the ulcer was clinically malacic at the time of sampling (OR = 10.1, p < .001). Ulcers treated prior to culture with fusidic acid were 7.6 times more likely to be positive than those treated with any other antimicrobial(s). Bacterial isolates demonstrated resistance against neomycin (85%), fusidic acid (78%), and tetracycline (68%). Conversely, isolates were most likely to be sensitive to gentamicin (88%), ofloxacin (77%), ciprofloxacin (73%), and chloramphenicol (64%). Antimicrobial combinations of chloramphenicol or gentamicin with a fluoroquinolone (ofloxacin or ciprofloxacin) or chloramphenicol combined with gentamicin were the most effective on invitro analysis (over 90% susceptibility of all isolates). The most common bacterial species associated with canine progressive ulcerative keratitis in a UK referral population were S. canis, P. aeruginosa, and S. pseudintermedius. Combination antimicrobial therapy is recommended pending culture and sensitivity results given the varied antimicrobial susceptibility profiles and significant bacterial invitro resistance to antimicrobial monotherapy.

Antibiotic adjuvant activities of quorum sensing signal molecules DSF and BDSF against mature biofilms of Staphylococci

Among promising antibiofilm compounds, quorum-sensing (QS) molecules that regulate biological processes such as biofilm formation and intra- or interspecies communication appear to be good candidates. The invitro antibiotic-adjuvant effects of QS molecules diffusible signal factor (DSF) and B. cenocepacia producing-DSF (BDSF) were investigated against mature Staphylococcal biofilms. Broth microdilution methods were used for the determinations of MIC, MBC, MBIC, and MBEC, and bactericidal activities were determined by TKC method. The lowest MICs were obtained with ciprofloxacin and gentamicin, and MBECs with ciprofloxacin. DSF and BDSF at 0.5 µM decreased the MICs as 2–8, and 2–32 fold, respectively. In TKC studies, –cidal activities were achieved by BDSF + gentamycin, or ciprofloxacin, and DSF + daptomycin, vancomycin, meropenem or gentamycin combinations. Synergistic effects were generally obtained with BDSF + gentamicin combinations, followed by DSF + daptomycin against most S. aureus; while BDSF + gentamicin or ciprofloxacin, and DSF + vancomycin or meropenem were synergist against some S. epidermidis biofilms. Also, the antagonist effects were observed with BDSF + meropenem or ciprofloxacin against each MSSE and MSSA. It is estimated that these QS molecules, although it was strain dependent, generally enhanced the antibiotic activity, and would be a new and effective treatment strategy for biofilm control, either alone or as an antibiotic adjuvant.

Patterns and determinants of antibiotic prescription among children admitted to public hospitals in Kenya: A cross-sectional observational study

Background: Sick children frequently have antibiotics prescribed as part of their treatment. Inappropriate use of antibiotics, especially broad-spectrum antibiotics, can result in the development of antibiotic resistance and the consequences of antibiotic resistance. In this study, we use routinely collected data to describe the patterns and identify factors influencing antibiotic prescription among admitted children. Methods: Routine data collected from medical records of children aged 2 months or older admitted between 2014 and 2020 to paediatric wards of 12 hospitals which are part of a Clinical Information Network (CIN) are used. Multivariable mixed effects logistic regression is used to assess determinants of antibiotic prescription with a random slope and intercept for hospital level. Results: A total of 127,984 antibiotic prescriptions were made in 107,500 participants included in the study where 81.1% (87,183/107,500) had one or more antibiotic prescriptions. The commonly prescribed antibiotics were a combination of benzylpenicillin and gentamicin (37,939/127,984 - 29.6%), ceftriaxone (31,172/127,984 - 24.6%) and oral amoxicillin (12,593 /127,984 - 9.8%). Factors associated with antibiotic prescription were history of cough (adjusted odds ratio (aOR), = 2.06, 95% confidence interval (CI):1.966 - 2.152), bloody diarrhoea (aOR=5.6, CI:4.453 - 7.036), diagnoses of pneumonia (aOR=27.66, CI:21.768 - 35.154), malnutrition (aOR=6.3, CI:4.558 - 8.701) and meningitis (aOR=11.85, CI:9.502 - 14.779). Antibiotic prescription was less likely in children diagnosed only with severe anaemia (aOR=0.8, CI:0.742 - 0.870), malaria (aOR:0.22, CI:0.201 - 0.231), diarrhoea (aOR:0.36, CI:0.331 - 0.398), and dehydration (aOR=0.4, CI:0.347 - 0.464). Conclusion: Antibiotics are prescribed in approximately four of every five children admitted to paediatric wards of Kenyan hospitals. Prescriptions are mainly in patients who fulfil syndromic clinical criteria where antibiotics are indicated. Without the introduction of reliable pathogen diagnostics, it will be difficult to reduce antibiotic prescriptions among admitted children.

Antibiotic use at a tertiary hospital in Tanzania: findings from a point prevalence survey

BackgroundIn Tanzania, data on antibiotic use at the patient level is scarce, and intervention measures to optimize antibiotic use and reduce antimicrobial resistance are rarely performed.ObjectivesTo describe antibiotic use at Muhimbili National Hospital.MethodsThis was a point prevalence survey on antibiotic use conducted at Muhimbili National Hospital in August-September 2022. The World Health Organization point prevalence survey data collection tool was used to collect patients’ information from the files. All patients admitted to the wards on the day of the survey were included.ResultsOverall, 47% (185/397) of admitted patients were on at least one antibiotic during the survey. All antibiotics prescribed were for empirical treatment and guideline compliance was low, at 45%. Of 185 patients who received antibiotics, the most common indication was community acquired infection (55%) and 36% had no documentation of the reasons for prescribing antibiotics. Almost 75% of the antibiotics were administered parenterally, with only 2% switching to oral route. Microbiological tests were performed in only 9 (5%) patients out of 185 and results were available for only one patient. Of all participants, 52% received two or more antibiotic in combination, with the combination ceftriaxone-metronidazole being most frequently prescribed, followed by the combination of ampicillin, cloxacillin, and gentamicin. For individual antibiotics, ceftriaxone was the most frequently prescribed antibiotic accounting for 28% (79/283), followed by metronidazole (24%) and amoxicillin-clavulanic acid (11%).ConclusionThe findings of a high prevalence of antibiotic use, inadequate use of bacterial culture, and frequent empiric antibiotic treatment suggests the need for strengthening diagnostic and antimicrobial stewardship programs. Furthermore, this study has identified areas for quality improvement, including education programs focusing on prescription practice.

Anti-fungal efficacy of combination of amphotericin B with colistin and gentamicin in McCarey-Kaufman corneal preservation medium.

To curtail the potential of donor corneal tissue disseminating fungi to the recipient's eye, we evaluated the addition of amphotericin B to McCarey-Kaufman (M-K)-corneal storage medium supplemented with colistin. Amphotericin B was examined for its ability to inhibit the growth of Candida albicans and Aspergillus flavus using a microbroth dilution test and checkerboard assay in combination with only gentamicin and a combination of colistin, gentamicin, and amphotericin B. The safety on epithelium and endothelium was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The minimal inhibitory concentration of gentamicin was found to be >256 μg/ml against both C. albicans and A. flavus, whereas that of amphotericin B was found to be in a range of 0.25-0.5 and 1-2 μg/ml for C. albicans and A. flavus, respectively. According to the checkerboard assay, 80% (4/5) of C. albicans isolates and 100% (5/5) of A. flavus isolates responded synergistically to the combination of amphotericin B and gentamicin, but only 20% (1/5) of C. albicans isolates showed an additive effect. None of the tested isolates displayed antagonism. The combined effect of the three drugs also did not display any antagonistic effect. Additionally, the MTT assay reveals no toxic effect of the antimicrobials used on corneal epithelial and endothelial cells. In vitro experiments demonstrate that amphotericin B is not toxic to either epithelium or endothelium and is a promising additive to the M-K medium supplemented with colistin.

Evaluation of the Antibacterial Activity of Gentamicin in Combination with Essential Oils Isolated from Different Cultivars and Morphological Parts of Lavender (Lavandula angustifolia Mill.) against Selected Bacterial Strains.

The aim of the study was to investigate the antibacterial effects of essential oils isolated from different cultivars and morphological parts of lavender (Lavandula angustifolia Mill.) in combination with the aminoglycoside antibiotic gentamicin. This in vitro study analyzed the effectiveness of the combinations of gentamicin and lavender essential oils against the following strains: Staphylococcus aureus ATCC 25923, Staphylococcus aureus MRSA and Pseudomonas aeruginosa ATCC 9027. The effect of the combination of lavender oils with gentamicin was tested using the checkerboard method. A synergistic effect against S. aureus strain ATCC 25923 was found when gentamicin was combined with lavender essential oils isolated from flowers and leafy stalks (flowers: 'Blue River' FICI-0.192; 'Ellagance Purple' FICI-0.288; leafy stalks: 'Blue River' FICI-0.192; 'Ellagance Purple' FICI-0.320). A synergistic effect was also observed for the combination of gentamicin with lavender essential oils from flowers against the resistant strain of S. aureus (MRSA) ('Blue River' FICI-0,191; 'Ellagance Purple' FICI-0.263), as well as for the essential oils from leafy stalks ('Blue River' FICI-0.076; 'Ellagance Purple' FICI-0.089). No interaction was observed for the combination of studied essential oils with gentamicin against P. aeruginosa strain ATCC 9027 (FICI = 1.083-1.300).

An in vitro analysis of various antibiotic cement combinations against Cutibacterium acnes

BackgroundCutibacterium acnes is the most common cause of prosthetic shoulder infection. Treatment often requires the placement of an antibiotic-loaded cement spacer. The exact combination of antibiotic and cement that best targets this organism is not fully understood. In this study, we performed an in vitro investigation of various antibiotic combinations in Simplex and Palacos cement to determine their efficacy against three C acnes strains. We hypothesized that gentamicin alone would underperform other antibiotics including vancomycin and ertapenem against C acnes in an in vitro environment. Additionally, we hypothesized that Palacos cement would outperform Simplex cement. MethodsStrains were cultured and antibiotic cement beads were plated in six combinations. Zones of inhibition (mm) were measured, and beads were transferred to a new culture plate at 7-day intervals. This procedure was carried out for 81 days. Mixed model for longitudinal repeated measures for continuous data was used to determine the antibiotic combination that produced the most robust zone of inhibition over time. ResultsFor vancomycin, gentamicin, and vancomycin + gentamicin, these data demonstrated that for two strains, Palacos cement with vancomycin and gentamicin produced the most robust zone of inhibition over time (P < .0001, P < .0001, respectively). For one strain, Palacos cement combined with vancomycin alone produced the most robust response (P < .0001). The second highest response for this strain was seen in Palacos cement combined with vancomycin and gentamicin. Ertapenem induced the largest response among all antibiotics that we tested against all 3 strains, but its effect was short-lived (one week or less) compared to vancomycin or vancomycin with gentamicin (35-81 days). Gentamicin response in both cement combinations against C acnes was weak and lasted at most 14 days. DiscussionThese data suggest that Palacos cement likely offers a better elution profile than Simplex in in vitro C acnes-related prosthetic shoulder infection strains. Vancomycin and gentamicin in combination demonstrated the most prolonged response for eradication of the 3 C acnes strains tested. Additionally, ertapenem may be a promising option as it showed a short-lived but robust clearing response. Gentamicin weakly inhibits C acnes growth calling into question its use in premade spacers.

Study on the inhibitory effect of quercetin combined with gentamicin on the formation of Pseudomonas aeruginosa and its bioenvelope

ObjectiveThe potential effects of quercetin and gentamicin combination on the bacteriostatic activity and biofilm formation of Pseudomonas aeruginosa (PA) were examined, and the findings provided a theoretical basis for the development of quercetin as a new biofilm inhibitor. MethodsThe minimum inhibitory concentration (MIC) of eight PAs was determined by microdilution method and the partial inhibitory concentration index (FICI) of the combined drug was analyzed by micro-dilution method. Thereafter, the lowest film inhibitory concentration (MBIC) of quercetin and gentamicin alone and in combination was evaluated by crystal violet staining. Finally, scanning electron microscopy (SEM) and laser confocal microscopy (CLSM) were used to decipher the inhibitory effect of the combination on biofilm formation. OutcomeThe antibacterial activity of quercetin alone was relatively weak, but after combination with gentamicin, the antibacterial activity was significantly enhanced, as evident by FICI of 0.28 and 0.53 and manifested as synergistic or additive effect, which indicated that quercetin can enhance gentamicin antibacterial activity. The results of crystal violet staining revealed that quercetin and gentamicin alone exhibited a similar biofilm formation inhibitory effect, but the inhibitory effect was substantially weaker, and the antibiofilm activity was stronger and exhibited a dose-dependent response after the combination of the two with 1/2FICI. The results of scanning electron microscopy and laser confocal microscopy also showed that the treatment of PA biofilm after combining quercetin and gentamicin with 1/2FICI could completely destroy the spatial structure of the complete biofilm, significantly reduce the thickness of bacteria, and markedly reduce the proportion of viable bacteria in the membrane. ConclusionThe combination of quercetin and gentamicin can effectively inhibit the formation of PA as well as its biofilm, and exhibit synergistic and additive effects.

Effect of Artemisia annua on kidney in gentamicin-induced nephrotoxicity in mice through regulation of the COX-2, NF-κB pathway

BackgroundThis study aimed to examine the role of Artemisia annua in kidney functions in gentamicin-induced nephrotoxicity in mice. MethodsIn this study, 15 mice were used and divided into four groups. Each group has four mice; the first group is considered a control group with three mice due to receiving normal saline. Group II consists of an extract of Artemisia annua, group III consists of gentamicin, and Group IV consists of a combination of Artemisia annua and gentamicin. This process was continued for 15 days. All the mice were induced, and serum was extracted and used for biochemical parameters such as Creatinine, Urea, Uric acid, TNF-α, MDA, GSH, and Catalase (CAT) levels—additionally, histological and quantitative real-time PCR (qRT-PCR) analysis. ResultsThe results of this study confirmed biochemical values such as creatinine, Urea, and UA values showed a positive association (p<0.05), and showed a nominal association with histological analysis (p > 0.05). The Gentamicin group has a strong association with COX-2, NF-κB, and TGF-β genes (p < 0.05). ConclusionThis study confirms gentamycin has a role in kidney functions with nephrotoxicity in mice and the protective effect of Artemisia annua.

The Potential Effects of the Essential Oil of Coriander Seeds on Bacterial Biofilm and Immune Cells

Background: Nowadays, the pharmacological activities of many natural phytochemicals have a huge impact on pharmaceutical research and drug development. Hence, numerous studies have been conducted to investigate plants' efficacy, fractions, and isolated pure compounds to discover new therapeutic agents. Aim: This study aimed to evaluate the potential activity of coriander essential oil (CEO) on bacterial biofilm and immune cells. Methods: CEO has been extracted from the seeds through the hydrodistillation method, and its chemical composition was analyzed using gas chromatography (GC) and Nuclear magnetic resonance (NMR). The antibacterial activity of CEO was assessed using different bacterial strains (P. aeruginosa, S. aureus, S. epidermidis and E. coli), both in planktonic and biofilm forms. In addition, this activity has been investigated individually and in combination with selected antibiotics (Gentamicin and Ciprofloxacin), using the bacterial enumeration following the MBEC Assay® protocol. Pyocianin (PYO) has been measured using a plate reader on 690 nm absorbance, where wells tested were treated with different CEO concentrations (12.5, 25, 50 and 100 mg/mL). An MTT assay was also used to examine the CEO'seffect on the viability of RAW 246.7 murine macrophages. Data were analyzed using GraphPad Prism 9 software. Results: Six major compounds were identified in CEO; Linalool was the most predominant. Regarding the activity of the CEO on planktonic bacteria, cell count was obtained and calculated as log reductions; significant log reductions (p&lt;0.05) were measured on 300 mg/mL of CEO for all P. aeruginosa, S. aureus, S. epidermidis and E. coli, 2.00, 6.73, 6.93 and 7.68 respectively. While for the bacterial biofilm, a significant (p&lt;0.05) log reduction in the cell count was obtained at 300 mg/mL of CEO for all of P. aeruginosa, S. aureus, S. epidermidis and E. coli, 2.22, 5.33, 5.83 and 6.76, respectively. Minimum inhibitory concentrations (MIC) of the combination of antibiotics Gentamicin (0.60, 0.15, 1.22, 0.3 µg/mL) or Ciprofloxacin (0.075, 0.03, 0.004 and 0.002 µg/mL) for all P. aeruginosa, S. aureus, S. epidermidis and E. coli, respectively, with 50 mg/mL of CEO on planktonic and biofilm bacteria. PYO measurements obtained showed anti-quorum sensing activity of CEO, the absorbance detecting PYO levels, was decreasing as the concentration of CEO was increasing, absorbances were (0.66, 0.075, 0.097 and 0.11), whereas the control of P. aeruginosa was (0.124). On the other hand, the antibacterial/antibiofilm concentrations were cytotoxic (percentage of viability &lt;80%) to macrophages and the safe level was (0.30 mg/mL) of CEO. Conclusion: These results indicated that CEO may have a promising role in bacterial biofilm eradication, which may help manage and prevent chronic infections in the future. However, more investigations are required to understand the exact mechanism and improve its safety on immune cells.

Development of a Polymicrobial Checkerboard Assay as a Tool for Determining Combinatorial Antibiotic Effectiveness in Polymicrobial Communities.

The checkerboard assay is a well-established tool used to determine the antimicrobial effects of two compounds in combination. Usually, data collected from the checkerboard assay use visible turbidity and optical density as a readout. While helpful in traditional checkerboard assays, these measurements become less useful in a polymicrobial context as they do not enable assessment of the drug effects on the individual members of the community. The methodology described herein allows for the determination of cell viability through selective and differential plating of each individual species in a community while retaining much of the high-throughput nature of a turbidity-based analysis and requiring no specialized equipment. This methodology further improves turbidity-based measurements by providing a distinction between bacteriostatic versus bactericidal concentrations of antibiotics. Herein, we use this method to demonstrate that the clinically used antibiotic combination of ceftazidime and gentamicin works synergistically against Pseudomonas aeruginosa in monoculture but antagonistically in a polymicrobial culture also containing Acinetobacter baumannii, Staphylococcus aureus, and Enterococcus faecalis, highlighting the fundamental importance of this methodology in improving clinical practices. We propose that this method could be implemented in clinical microbiology laboratories with minimal impact on the overall time for diagnosis.

Antimicrobial Properties and Substantivity of Gentamicin, Amoxicillin and Metronidazole (GAM) Antibiotic Solution with Chitosan as a Root Canal Irrigant - A Preliminary Study.

The combination of gentamicin, amoxicillin, and metronidazole (GAM) solution with chitosan (GAMC) can be used as an alternative intracanal irrigant as it was found to be a potent antibacterial agent.

Review of the national usage of antibiotics in arthroplasty surgery: a need for evidence-based prescribing.

Surgical site infections (SSI) remain one of the most serious complications of arthroplasty surgery. The role of antibiotic prophylaxis in preventing SSI post-arthroplasty is well established. However, there is considerable heterogeneity in prophylactic prescribing across the United Kingdom (UK), which is contradicted by the contemporaneous evidence. This descriptive study aimed to compare the current first-line antibiotic recommendations across hospitals in the UK and The Republic of Ireland for elective arthroplasty procedures. The MicroGuide mobile phone application was used to access hospital antibiotic guidelines. First-line antibiotic recommendation and dosing regimen for primary elective arthroplasties were recorded. A total of nine distinct antibiotic regimens were identified through our search. The most frequently used first-line antibiotic was cefuroxime. This was recommended by 30 of the 83 (36.1%) hospitals in the study. This was followed by a combination of flucloxacillin and gentamicin, which was used by 38 of 124 (31%) hospitals. There was also significant heterogeneity in dosing regimens. A single prophylactic dose was most commonly recommended (52%); 4% of hospitals recommended two prophylactic doses, 19% three doses and 23% four doses. Single-dose prophylaxis is recognised as at least noninferior to multiple-dose prophylaxis in primary arthroplasty. There is considerable variation in the local antibiotic recommendations for surgical site prophylaxis post-primary arthroplasty surgery, with respect to both recommended first-line antibiotic and dosing regimens. With increasing emphasis on the importance of antibiotic stewardship and the emergence of antibiotic resistance, this study highlights the need for an evidence-based approach to prophylactic dosing across the UK.

Cefotaxime/sulbactam plus gentamicin as a potential carbapenem- and amikacin-sparing first-line combination for neonatal sepsis in high ESBL prevalence settings.

Infection with ESBL-producing Enterobacteriaceae infection is ubiquitous in some neonatal ICUs and increasing levels of antibiotic resistance are a cause for urgent concern. Delineation of bacterial and viral sepsis can be challenging, often leading to patients receiving empirical antibiotics without or whilst waiting for a definitive causal diagnosis. Empirical therapy is often dependent on broad-spectrum 'Watch' antibiotics, contributing to further resistance. ESBL-producing Enterobacteriaceae clinical isolates found to have caused neonatal sepsis and meningitis underwent a detailed in vitro screening including susceptibility testing, chequerboard combination analysis and hollow-fibre infection model dynamic analyses using combinations of cefotaxime, ampicillin and gentamicin in combination with β-lactamase inhibitors. Additivity or synergy was found for all antibiotic combinations against seven Escherichia coli and three Klebsiella pneumoniae clinical isolates. Cefotaxime or ampicillin plus sulbactam combined with gentamicin was able to consistently inhibit the growth of ESBL-producing isolates at typical neonatal doses, and the combination cleared the hollow-fibre infection model system of organisms resistant to each agent alone. The combination of cefotaxime/sulbactam and gentamicin was consistently bactericidal at clinically achievable concentrations (Cmax of 180, 60 and 20 mg/L for cefotaxime, sulbactam and gentamicin, respectively). The addition of sulbactam to cefotaxime or ampicillin to the typical first-line empirical therapy could obviate the need for carbapenems and amikacin in settings with high ESBL-infection prevalence.

The pygidial gland secretion of Laemostenus punctatus (Coleoptera, Carabidae): a source of natural agents with antimicrobial, anti-adhesive, and anti-invasive activities

In the present study, we investigated in vitro the antimicrobial activity of the pygidial gland secretion of the guanophilic ground beetle Laemostenus (Pristonychus) punctatus (Dejean, 1828) and some of its chemicals against resistant and non-resistant bacteria and Candida species, the synergistic and additive potential of combinations of selected chemicals and antimicrobial drugs against resistant bacterial and fungal strains, anti-adhesive and anti-invasive potential of the secretion and formic acid alone and in selected combinations with antimicrobial drugs against methicillin-resistant Staphylococcus aureus (MRSA) toward spontaneously immortalized human keratinocyte cell line (HaCaT cells). In addition, we examined the antiproliferative activity of the secretion and formic acid in vitro. The tested secretion and the standards of formic and oleic acids possessed a significant level of antimicrobial potential against all tested strains (P &amp;lt; 0.05). The isolate from guano Pseudomonas monteilii showed the highest resistance to the secretion and formic acid, while MRSA achieved a significantly high level of susceptibility to all agents tested, particularly to the combinations of formic acid and antibiotics, but at the same time showed a certain level of resistance to the antibiotics tested individually. Candida albicans and C. tropicalis were found to be the most sensitive fungal strains to the secretion. Formic acid (MIC 0.0005 mg/mL) and gentamicin (MIC 0.0010 mg/mL) in the mixture achieved synergistic antibacterial activity against MRSA (FICI = 0.5, P &amp;lt; 0.05). The combination of formic acid, gentamicin and ampicillin accomplished an additive effect against this resistant bacterial strain (FICI = 1.5, P &amp;lt; 0.05). The secretion achieved a better inhibitory effect on the adhesion ability of MRSA toward HaCaT cells compared to formic acid alone, while formic acid showed better results regarding the invasion (P &amp;lt; 0.001). The combinations of gentamicin and ampicillin, as well as of formic acid and gentamicin and ampicillin achieved similar anti-adhesive and anti-invasive effects, with a slight advantage of formic acid and antibiotics in combination (P &amp;lt; 0.001). The secretion and formic acid were found to be non-toxic to HaCaT cells in vitro (IC50 ≥ 401 μg/mL).

In vitro reduction of Escherichia coli biofilm mass by platelet-rich plasma lysate (PRP-L)

Placentitis-induced, pre-term fetal loss has caused hardships and financial losses to the equine breeding industry for decades. While traditional multi-modal treatments including a combination of gentamicin, penicillin, altrenogest, firocoxib, and pentoxifylline can sometimes prolong gestation and neonatal survival, treatment failures still occur and antibiotic therapy can be quite lengthy. Understanding potential biofilms in these reproductive infections uncovers a pitfall to the success of traditional treatment options: antimicrobials are ineffective at penetrating and killing biofilms in vitro and in vivo. Platelet-rich plasma lysate (PRP-L) is increasingly accepted as an adjunctive treatment option for biofilm associated infections across species. The aim of this study was to evaluate the reduction in biofilm formation of 10 isolates of Escherichia coli collected from the equine uterus. Isolates were stored in glycerol at -80°C; each isolate including a positive (ATCC 25922) and negative (ATCC BAA 2469) strain, was cultured for 18-24 h at 33-37°Cin ambient air until bacterial colonies were visible. A suspension of each isolate, adjusted to a 0.5 McFarland value, was used to inoculate a tissue culture treated, round-bottom 96-well microtiter plate incubated under microaerophilic orbital shaking conditions for 18-24 h at 33-37°C. Following incubation, with or without PRP-L, the supernatant was removed, wells were stained with 0.03% crystal violet for 15 minutes at room temperature with orbital shaking, rinsed to remove excess stain, solubilized with ethanol, and absorbance optical density (OD570) read with a plate reader. The range in reduction of biofilm mass with PRP-L treatment was 48 – 84%, with an average of 60%. In conclusion, the results suggest that comparison of a traditional multi-modal therapy for placentitis with a multi-modal therapy augmented with PRP-L has the potential to finally improve placentitis outcomes and reduce the length of antibiotic treatment, but further in vivo evaluation of this approach is required.

Local Gentamicin Fixation with Sprayed Fibrin-An In Vivo Animal Study Reveals New Options to Treat Soft Tissue Infections.

For acute and chronic soft tissue infections, radical surgical debridement is required and is considered the gold standard, along with its immediate systemic antibiotic therapy. Treatment with local antibiotics and/or antibiotic-containing materials is commonly used as an additional tool in clinical practice. Spraying with fibrin and antibiotics is a newer technique that has been studied for some antibiotics. However, for gentamicin, data are not yet available on absorption, optimal application, antibiotic fate at the site and transfer of antibiotic into the blood. In an animal study involving 29 Sprague Dawley rats, 116 back wounds were sprayed with gentamicin using either gentamicin alone or one of two possible spray combinations of gentamicin and fibrin. Simultaneous application of gentamicin and fibrin via a spray system to soft tissue wounds resulted in significant antibiotic concentration over a long period of time. The technique is easy and cost-effective. The systemic crossover was significantly minimized in our study, which may have led to fewer side effects in patients. These results could lead to an improvement in local antibiotic therapy.

Combination of gentamicin and clindamycin as a promising therapy for multidrug-resistant (MDR) methicillin-resistant Staphylococcus aureus isolated in Enugu State

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is prevalent in Nigeria. Due to its increasing resistance to treatments with single antibiotics, such as vancomycin and others, it has become necessary to identify appropriate combination of antibiotics for treatment. This research tested the proneness of MRSA isolated in southeastern Nigeria to a combined treatment of selected antibiotics (vancomycin, clindamycin, gentamicin, and ceftriaxone), to identify the best combination for the treatment of MRSA isolated in the region. Methods: Various samples from patients were obtained in three laboratories in Enugu, Nigeria and cultured for isolation and purification. Minimum inhibitory concentration of vancomycin, clindamycin, gentamicin, and ceftriaxone antibiotics against the purified isolates was determined and the combined activity of the drugs on the isolates was also evaluated using Checkerboard-technique. Results: MRSA isolates were found to be highly prevalent in the clinical samples. They also showed multidrug-resistant traits. The different combinations of antibiotics against different species of MRSA indicated synergistic, indifferent, additive, and antagonistic effects. The best combination that could treat muti-drug resistant MRSA was found to be gentamycin and clindamycin. MRSA has developed resistance to many drugs, making its infections difficult to treat. The combination of gentamicin and clindamycin is a promising strategy for treating MRSA in the region.