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Annals of Clinical Microbiology and... Oct 2006combinations of drugs has been proposed as an alternative for oxacillin-resistant staphylococci infections, however, limited information about in vitro combinations are...
BACKGROUND
combinations of drugs has been proposed as an alternative for oxacillin-resistant staphylococci infections, however, limited information about in vitro combinations are available for multi-resistant strains. The objective of this study was to describe the interaction of beta-lactams in combination with vancomycin or amikacin against 26 oxacillin and amikacin-resistant nosocomial Staphylococcus spp. isolates.
METHODS
activity of dicloxacillin plus amikacin, cephalothin plus amikacin, cephalothin plus vancomycin, imipenem plus vancomycin and vancomycin plus amikacin was evaluated by checkerboard synergy tests and the fractional inhibitory concentration index (FIC) was calculated.
RESULTS
dicloxacillin plus amikacin, and cephalothin plus amikacin were synergistic or partially synergistic in 84.6% and 100% respectively. For nearly half of the isolates the mean concentrations of dicloxacillin, cephalothin and amikacin at which FIC indexes were calculated were achievable therapeutically. Vancomycin plus amikacin had synergistic effect only against two isolates, and partially synergistic in 38.6%. For the combinations vancomycin plus cephalothin and vancomycin plus imipenem the effect was additive in 76.9% and 80.7% respectively.
CONCLUSION
in this study the checkerboard analysis showed that amikacin in combination with cephalothin or dicloxacillin was synergistic against most of the resistant strains of S. aureus and coagulase-negative Staphylococcus. Vancomycin in combination with a beta-lactam (cephalothin or imipenem) showed additivity. An indifferent effect predominated for the combination vancomycin plus amikacin. Even though a synergistic effect is expected when using a beta-lactam plus amikacin combination, it is possible that the effect cannot be clinically achievable. Careful selection of antimicrobial combinations and initial MICs are mandatory for future evaluations.
Topics: Amikacin; Anti-Bacterial Agents; Cephalothin; Dicloxacillin; Drug Synergism; Drug Therapy, Combination; Electrophoresis, Gel, Pulsed-Field; Humans; Imipenem; Methicillin Resistance; Microbial Sensitivity Tests; Staphylococcus; Staphylococcus aureus; Vancomycin; beta-Lactams
PubMed: 17034644
DOI: 10.1186/1476-0711-5-25 -
International Journal of Dentistry 2021Severe periodontal disease is highly prevalent worldwide, affecting 20% of the population between the ages of 35 and 44 years. The etiological epidemiology in Peru is...
BACKGROUND
Severe periodontal disease is highly prevalent worldwide, affecting 20% of the population between the ages of 35 and 44 years. The etiological epidemiology in Peru is scarce, even though some studies describe a prevalence of 48.5% of periodontal disease in the general population. Periodontitis is one of the most prevalent oral diseases associated with site-specific changes in the oral microbiota and it has been associated with a socioeconomic state. This study aimed to determine the etiology and resistance profile of bacteria identified in a group of Peruvian patients with periodontal disease.
METHODS
Six subgingival plaque samples were collected from eight patients with severe periodontitis. Bacterial identification was carried out by an initial culture, PCR amplification, and subsequently DNA sequencing. We evaluated the antibiotic susceptibility by the disk diffusion method.
RESULTS
Variable diversity in oral microbiota was identified in each one of the eight patients. The bacterial genus most frequently found was spp. (15/48, 31.3%) followed by spp. (11/48, 22.9%), spp. (9/48, 18.8%), and spp. (4/48, 8.3%). The most common species found was (8/48, 16.7%). The antimicrobial susceptibility assay varied according to the species tested; however, among all the isolates evaluated, was resistant to penicillin and tetracycline; was resistant to dicloxacillin; and was resistant to amoxicillin + clavulanic acid and metronidazole but also susceptible to trimethoprim-sulfamethoxazole.
CONCLUSIONS
The most prevalent periodontal bacterium found in this study was Specific antimicrobial therapy is required to improve the treatment outcomes of patients with periodontal disease and avoid antibiotic resistance.
PubMed: 33679978
DOI: 10.1155/2021/2695793 -
Antimicrobial Agents and Chemotherapy May 2009Antibiotic treatment of Staphylococcus aureus infections is often problematic due to the slow response to therapy and the high frequency of infection recurrence. The...
Antibiotic treatment of Staphylococcus aureus infections is often problematic due to the slow response to therapy and the high frequency of infection recurrence. The intracellular persistence of staphylococci has been recognized and could offer a good explanation for these treatment difficulties. Knowledge of the interplay between intracellular antibiotic activity and the overall outcome of infection is therefore important. Several intracellular in vitro models have been developed, but few experimental animal models have been published. The mouse peritonitis/sepsis model was used as the basic in vivo model exploring a quantitative ex vivo extra- and intracellular differentiation assay. The intracellular presence of S. aureus was documented by electron microscopy. Five antibiotics, dicloxacillin, cefuroxime, gentamicin, azithromycin, and rifampin (rifampicin), were tested in the new in vivo model; and the model was able to distinguish between their extra- and intracellular effects. The intracellular effects of the five antibiotics could be ranked as follows as the mean change in the log(10) number of CFU/ml (Delta log(10) CFU/ml) between treated and untreated mice after 4 h of treatment: dicloxacillin (3.70 Delta log(10) CFU/ml) > cefuroxime (3.56 Delta log(10) CFU/ml) > rifampin (1.86 Delta log(10) CFU/ml) > gentamicin (0.61 Delta log(10) CFU/ml) > azithromycin (0.21 Delta log(10) CFU/ml). We could also show that the important factors during testing of intracellular activity in vivo are the size, number, and frequency of doses; the time of exposure; and the timing between the start of infection and treatment. A poor correlation between the intracellular accumulation of the antibiotics and the actual intracellular effect was found. This stresses the importance of performing experimental studies, like those with the new in vivo model described here, to measure actual intracellular activity instead of making predictions based on cellular pharmacokinetic and MICs.
Topics: Animals; Animals, Outbred Strains; Anti-Bacterial Agents; Colony Count, Microbial; Dicloxacillin; Dose-Response Relationship, Drug; Female; Humans; Mice; Microbial Sensitivity Tests; Peritoneum; Peritonitis; Rifampin; Sepsis; Staphylococcal Infections; Staphylococcus aureus; Treatment Outcome
PubMed: 19223616
DOI: 10.1128/AAC.01605-07 -
Tropical Medicine and Infectious Disease Jun 2023Snakebite envenoming is an occupational hazard in remote rural areas of South Thailand, where the highest incidence of snakebites is reported. In this work, a...
Snakebite envenoming is an occupational hazard in remote rural areas of South Thailand, where the highest incidence of snakebites is reported. In this work, a hospital-based retrospective study of snakebite patients from 2012 to 2022 at Fort Wachirawut Hospital and Fort Thepsatrisrisunthon Hospital, located in Nakhon Si Thammarat province, Thailand was conducted. Data from the laboratory investigation, physical examinations of snakebite victims, and clinical management, including pharmacological and non-pharmacological treatments, were evaluated. A total of 54 snakebite victims were included. The median age of patients was 49 years (IQR, 28 to 63). Males accounted for 74.1% of all participants. The majority of patients were bitten by Malayan pit vipers (68.5%), followed by unidentified snakes (18.5%), other non-venomous snakes (7.4%), and cobras (5.6%). The most common clinical manifestations were swelling (90.2%) and local pain (73.2%). One patient experienced respiratory failure following an envenoming by an unidentified venomous snake. No deaths were observed in this study. In total, 24 patients received antivenom administration (44.4%), most of whom were from Fort Wachirawut Hospital. Patients who were administered antivenom showed a median admission duration of three days (IQR, 3 to 4), compared with two days (IQR, one to three) for those who did not receive antivenom treatment ( < 0.001). In addition, paracetamol and prophylactic antibiotics, namely, amoxicillin-clavulanate and dicloxacillin, were the most common pharmacotherapies following snakebites. Overall, it was observed that these two community hospitals undertook appropriate clinical management under the standard guidelines for snakebite patients. This might be due to the effective emergency management, facilities, and clinical consultations. Finally, the management process in the medical teams also plays a crucial role in minimizing the severity of snakebite outcomes.
PubMed: 37505642
DOI: 10.3390/tropicalmed8070346 -
International Journal of Veterinary... Dec 2016Administration of vitamin, mineral and antimicrobials at the end of lactation plays potential role in preventing mastitis in dairy cows. A total of 255 cows dividing...
Administration of vitamin, mineral and antimicrobials at the end of lactation plays potential role in preventing mastitis in dairy cows. A total of 255 cows dividing into five groups (A = 50, B = 50, C = 50, D = 50 and E = 55) at their late gestation period were selected to explore the effect of vitamin E, selenium and antimicrobial therapy on mastitis incidence, their productive and reproductive performances. Each cow of group A received α-tocopherol + sodium selenite orally daily for last 30 days before calving, while each cow of group B, C and D was treated with α-tocopherol + sodium selenite intramuscular injection, procaine penicillin + neomycin sulfate, and dicloxacillin sodium intramammary infusions at Day 30-20 before calving, respectively. Group E cows served as untreated control. California mastitis test (CMT) revealed that 70.0%, 76.0%, 84.0% and 100.0% cows in group A, B, C and D, respectively were free from new intramammary infections (IMIs) during early lactation period. The bacteriological results showed highest IMIs rates (76.3%) in group E and lowest IMIs (2.0%) in group D ( < 0.05). and were the most predominant udder pathogens in all groups except group D (only CNS). The mean IMIs incidence (20.5%) was significantly lower in treated cows ( < 0.001). The treated cows had higher cure rates (81.9%) than control cows (23.1%) and overall efficacy of treatments on cure rates was 71.8% for all mastitis pathogens ( < 0.0001). The productive and reproductive performances of the treated cows at postpartum and early lactation period remained always higher than their non-treated counterparts ( < 0.001). A number of cow and herd related factors were identified to be significantly associated with mastitis ( < 0.001). The results concluded that antimicrobial therapy had more beneficial effect in preventing mastitis over vitamin-mineral administration and intramammary infusion with dicloxacillin sodium remained as the best effective preventive strategies for mastitis in dairy cows.
PubMed: 30255040
DOI: 10.1016/j.ijvsm.2016.11.001 -
Clinical and Experimental Emergency... Mar 2021Centipede stings are a common problem in tropical countries. Current treatment guidelines do not include recommendations for antibiotic prophylaxis to prevent the...
OBJECTIVE
Centipede stings are a common problem in tropical countries. Current treatment guidelines do not include recommendations for antibiotic prophylaxis to prevent the associated bacterial infection since no previous study has assessed the effectiveness of antibiotic treatment in patients bitten by centipedes. Thus, this study aimed to compare the effectiveness of antibiotic prophylaxis over placebo for the skin infections that occur after a centipede sting.
METHODS
In this randomized, double-blind, multi-center clinical trial conducted in the emergency departments in four hospitals, patients with any history of a centipede sting were prospectively enrolled and divided randomly into two groups. One group received dicloxacillin and the other a placebo. The primary outcome was the incidence of wound infection 3 to 5 days after the centipede sting.
RESULTS
From December 2014 to October 2015, a total of 83 patients were enrolled in the study and were randomized into antibiotic (n=43) and placebo (n=40) groups. Two patients in the antibiotic group developed wound infections, while none showed wound infection in the placebo group (5% vs. 0%). The wound infection rate did not differ significantly between the two groups (P=0.496).
CONCLUSION
Antibiotic prophylaxis may be unnecessary in cases of centipede stings. Proper wound care is an adequate and appropriate treatment for patients with centipede stings. However, the patient should be re-evaluated for detection of secondary bacterial infection.
PubMed: 33845522
DOI: 10.15441/ceem.20.110 -
Antimicrobial Agents and Chemotherapy Mar 1974Current interest in antimicrobial susceptibility testing of anaerobic pathogens and recent recognition that actinomycetes other than Actinomyces israelii may cause...
Current interest in antimicrobial susceptibility testing of anaerobic pathogens and recent recognition that actinomycetes other than Actinomyces israelii may cause actinomycosis in man prompted this in vitro survey of 74 strains of actinomycetes, representing seven species. Minimum inhibitory concentrations (MICs) for 24 antimicrobials were determined by inhibition of gross colonial enlargement in semisolid antibiotic agar after incubation at 37 C for 48 h under anaerobic conditions. Erythromycin and rifampin were the most active drugs in vitro (MICs of 0.008 to 0.25 mug/ml), although a small number of non-israelii strains were conspicuously more resistant to the latter (MICs >0.5 mug/ml). Penicillin G, cephaloridine, minocycline, and clindamycin were also very active in vitro (MICs of 0.03 to 1.0 mug/ml); for a few non-israelii strains the MICs of clindamycin were 2.0 to 8.0 mug/ml. MICs of cephalothin, ampicillin, lincomycin, tetracycline, doxycycline, and chloramphenicol were well within a therapeutic range for all strains of A. israelii and most other species, although the MIC of lincomycin against a few non-israelii strains and of tetracycline and doxycycline against the majority of these strains was 2.0 to 8.0 mug/ml. Oxacillin, dicloxacillin, and cephalexin were less active in vitro, particularly against strains other than A. israelii. Most non-israelii species were not suppressed by 125 mug of metronidazole per ml, which concentration inhibited all strains of A. israelii; otherwise, there were no antimicrobial susceptibility differences among the species tested. Aminoglycoside activity was negligible.
Topics: Actinomyces; Anti-Bacterial Agents; Microbial Sensitivity Tests; Species Specificity
PubMed: 4840438
DOI: 10.1128/AAC.5.3.302 -
BMC Infectious Diseases Oct 2021Delafloxacin is a novel fluoroquinolone with broad antibacterial activity against pathogens causing acute bacterial skin and skin structure infections (ABSSSI). This...
BACKGROUND
Delafloxacin is a novel fluoroquinolone with broad antibacterial activity against pathogens causing acute bacterial skin and skin structure infections (ABSSSI). This network meta-analysis (NMA) was conducted to evaluate the relative efficacy of delafloxacin versus other comparators used for managing patients with ABSSSI.
METHODS
A systematic literature review was conducted to identify randomised controlled trials (RCTs) evaluating adults (≥ 18 years) with ABSSSI, complicated SSSI (cSSSI), complicated skin and soft tissue infections (cSSTI) or severe cellulitis with pathogen of gram-positive, gram-negative, or mixed aetiology. OVID MEDLINE, Embase, Epub Ahead of Print, Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews were searched from inception through 12 April 2019. A feasibility assessment was conducted, followed by an NMA, which was run in a Bayesian framework. The interventions included in the NMA encompassed monotherapy or combination therapies of amoxicillin/clavulanate, ampicillin/sulbactam, ceftaroline, ceftobiprole, dalbavancin, daptomycin, delafloxacin, fusidic acid, iclaprim, linezolid, omadacycline, oxacillin + dicloxacillin, standard therapy, tedizolid, telavancin, tigecycline, vancomycin, vancomycin + aztreonam and vancomycin + linezolid.
RESULTS
A feasibility assessment was performed and evidence networks were established for composite clinical response (n = 34 studies), early clinical response (n = 16 studies) and microbiological response (n = 14 studies) in the overall study population, composite clinical response (n = 4 studies) in obese subpopulation and for composite clinical response (n = 18 studies) and microbiological response (n = 14 studies) in patients with methicillin-resistant Staphylococcus aureus (MRSA) infection. Delafloxacin performed significantly better than fusidic acid, iclaprim, vancomycin, and ceftobiprole for composite clinical response. Delafloxacin was comparable to dalbavancin, daptomycin, fusidic acid, iclaprim, linezolid, omadacycline, tedizolid, vancomycin, vancomycin + aztreonam and vancomycin + linezolid in the analysis of early clinical response, whereas for microbiological response, delafloxacin was comparable to all interventions. In the obese subpopulation, the results favoured delafloxacin in comparison to vancomycin, whilst the results were comparable with other interventions among the MRSA subpopulation.
CONCLUSIONS
Delafloxacin is a promising new antibiotic for ABSSSI demonstrating greater improvement (composite clinical response) compared to ceftobiprole, fusidic acid, iclaprim, telavancin and vancomycin and comparable effectiveness versus standard of care for all outcomes considered in the study.
Topics: Adult; Fluoroquinolones; Humans; Network Meta-Analysis; Skin Diseases, Infectious; Systematic Reviews as Topic
PubMed: 34610820
DOI: 10.1186/s12879-021-06736-x -
Applied Microbiology Apr 1970A previously described agar-diffusion technique for microbioassay of antimicrobial agents has been modified to increase sensitivity of the technique and to extend the...
A previously described agar-diffusion technique for microbioassay of antimicrobial agents has been modified to increase sensitivity of the technique and to extend the range of antimicrobial agents to which it is applicable. This microtechnique requires only 0.02 ml of an unknown test sample for assay, and is capable of measuring minute concentrations of antibiotics in buffer, serum, and urine. In some cases, up to a 20-fold increase in sensitivity is gained relative to other published standardized methods and the error of this method is less than +/-5%. Buffer standard curves have been established for this technique, concurrently with serum standard curves, yielding information on antimicrobial serum-binding and demonstrating linearity of the data points compared to the estimated regression line for the microconcentration ranges covered by this technique. This microassay technique is particularly well suited for pediatric research and for other investigations where sample volumes are small and quantitative accuracy is desired. Dilution of clinical samples to attain concentrations falling with the range of this assay makes the technique readily adaptable and suitable for general clinical pharmacological studies. The microassay technique has been standardized in buffer solutions and in normal human serum pools for the following antimicrobials: ampicillin, methicillin, penicillin G, oxacillin, cloxacillin, dicloxacillin, cephaloglycin, cephalexin, cephaloridine, cephalothin, erythromycin, rifamycin amino methyl piperazine, kanamycin, neomycin, streptomycin, colistin, polymyxin B, doxycycline, minocycline, oxytetracycline, tetracycline, and chloramphenicol.
Topics: Agar; Anti-Bacterial Agents; Bacillus cereus; Biological Assay; Bordetella; Buffers; Colorimetry; Diffusion; Humans; Methods; Sarcina; Staphylococcus; Statistics as Topic
PubMed: 4986725
DOI: 10.1128/am.19.4.573-579.1970 -
Journal of Chromatography. A Nov 2021The presence of antibiotics in the aquatic environment is becoming one of the main research focus of scientists and policy makers. Proof of that is the inclusion of four...
The presence of antibiotics in the aquatic environment is becoming one of the main research focus of scientists and policy makers. Proof of that is the inclusion of four antibiotics, amongst which is amoxicillin, in the EU Watch List (WL) (Decision 2020/1161/EU)) of substances for water monitoring. The accurate quantification of amoxicillin in water at the sub-ppb levels required by the WL is troublesome due to its physicochemical properties. In this work, the analytical challenges related to the determination of amoxicillin, and six related penicillins (ampicillin, cloxacillin, dicloxacillin, penicillin G, penicillin V and oxacillin), have been carefully addressed, including sample treatment, sample stability, chromatographic analysis and mass spectrometric detection by triple quadrupole. Given the low recoveries obtained using different solid-phase extraction cartridges, we applied the direct injection of water samples using a reversed-phase chromatographic column that allowed working with 100% aqueous mobile phase. Matrix effects were evaluated and corrected using the isotopically labelled internal standard or correction factors based on signal suppression observed in the analysis of spiked samples. The methodology developed was satisfactorily validated at 50 and 500 ng L for the seven penicillins studied, and it was applied to different types of water matrices, revealing the presence of ampicillin in one surface water sample and cloxacillin in three effluent wastewater samples.
Topics: Amoxicillin; Ampicillin; Chromatography, High Pressure Liquid; European Union; Penicillins; Solid Phase Extraction; Water
PubMed: 34662823
DOI: 10.1016/j.chroma.2021.462605