Serum bactericidal testing with quality control organisms

Measurements of serum bacteriostatic and bactericidal titers were compared using common quality control organisms. Oxacillin or vancomycin was added to normal sera for duplicate testing against Staphylococcus aureus ATCC 25923 while gentamicin or ampicillin was added for duplicate testing against Escherichia coli ATCC 25922. Recommendations of acceptable ranges are presented in the text. Establishment of acceptable ranges for serum bactericidal assay results could improve accuracy, allow comparisons of data from different studies and help reduce intralaboratory variations.     

Comparative in vitro activity of telavancin, vancomycin and linezolid against heterogeneously vancomycin-intermediate Staphylococcus aureus (hVISA)

Selective pressure from glycopeptide use has led to non-susceptible strains of Staphylococcus aureus, including heterogeneously vancomycin-intermediate S. aureus (hVISA). Treatment of hVISA infections with vancomycin has been associated with treatment failure, therefore new treatments are required. The objective of this study was to evaluate the activity of telavancin, vancomycin and linezolid against hVISA clinical strains. Twenty-five hVISA isolates were evaluated for minimum inhibitory concentrations (MICs) by microdilution and for bactericidal activity by time-kill analysis [starting inoculum ca. 10(6)colony-forming units (CFU)/mL and ca. 10(8)CFU/mL] against telavancin, vancomycin and linezolid. MICs for 50% and 90% of the organisms (MIC(50) and MIC(90) values, respectively) were, respectively, 0.5mg/L and 1mg/L for telavancin and 2mg/L and 2mg/L for both vancomycin and linezolid. In time-kill studies, telavancin was bactericidal against all strains at plasma peak and trough concentrations and at low and high inocula. At low inoculum, the time to bactericidal activity (defined as 99.9% kill from initial inoculum) (T(99.9)) for telavancin was 5.6 ± 3.2 h at peak concentration and 12.3 ± 5.2 h at trough concentration. This was superior to vancomycin (P<0.001), which had a T(99.9) of 18.8 ± 2.1 h at peak concentration and 19.1 ± 2.2 h at trough concentration. At high inoculum, telavancin had a T(99.9) of 16.3 ± 3.2 h at peak concentration and 21.4 ± 2.5 h at trough concentration, whilst vancomycin did not consistently achieve bactericidal activity. Linezolid was not bactericidal against any strain at either concentration or inoculum. In conclusion, the killing activity of telavancin against hVISA was found to be superior to vancomycin and linezolid.     

Syntheses, in vitro antibacterial and cytotoxic activities of a series of 3-substituted succinimides

We have synthesized a series of 3-substituted succinimides and their in vitro antibacterial activities have been tested towards Gram-positive and Gram-negative bacteria from the ATCC collection. Some of them possess significant antibacterial activity against Gram-positive organisms (Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212) but all are poorly active or inactive against Gram-negative organisms (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853). The compounds with the lowest minimal inhibitory concentrations (esters of 3-hydroxy succinimides) are also the most cytotoxic against green monkey Vero cell line (ATCC CCL-81) and could explain that perhaps apoptosis should be implicated in eukaryotic cell cytotoxicity of succinimides.     

Activity of oritavancin and comparators in vitro against standard and high inocula of Staphylococcus aureus

In this study, the impact of inoculum density on the growth inhibitory and killing activities of oritavancin and comparators (vancomycin, daptomycin and linezolid) in vitro against four Staphylococcus aureus strains at clinically relevant drug concentrations was studied. Broth microdilution and time-kill assays were performed using a standard inoculum [ca. 10(5)colony-forming units (CFU)/mL as per Clinical and Laboratory Standards Institute (CLSI) guidelines] and a high inoculum (ca. 10(7)CFU/mL). Whereas minimal inhibitory concentrations (MICs) of comparators were 2-8-fold higher when tested at high inoculum, oritavancin MICs were 16-fold higher for all strains at the high inoculum relative to the standard inoculum. However, in time-kill assays, when tested at its fC(min) [trough concentration of free (non-protein-bound) drug] and fC(max) (peak concentration of non-protein-bound drug), oritavancin retained its bactericidal activity against a vancomycin-susceptible, meticillin-susceptible S. aureus (VS-MSSA) strain and a vancomycin-susceptible, meticillin-resistant S. aureus (VS-MRSA) strain both at standard and high inocula. At its fC(max), oritavancin was bactericidal at standard inoculum but not at high inoculum against two vancomycin-intermediate S. aureus (VISA) strains. Against both VISA strains at standard inoculum, oritavancin at its fC(min) reduced cell density by between 2 and 3 log (bacteriostatic), predicting that it will retain activity against certain VISA infections. However, oritavancin had no substantial growth inhibitory effect against either VISA strain at high inoculum, suggesting that in rare VISA infections with an anticipated high bacterial burden such as endocarditis, alternative oritavancin dosing strategies, including combinations with other agents, may be explored.     

ε-聚赖氨酸对金黄色葡萄球菌生长及生物膜形成的影响#br#

目的 研究ε-聚赖氨酸(ε-poly-L-lysine, ε-PL)对金黄色葡萄球菌(Staphylococcus aureus, S. aureus)生长及生物膜形成的影响。方法 以金黄色葡萄球菌标准菌株ATCC25923及社区获得性耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus, MRSA)USA300为试验菌株,常量肉汤稀释法(试管)测定最低抑菌浓度(minimum inhibitory concentration, MIC),酶标仪检测吸光度法观察各株金黄色葡萄球菌的生长曲线,96孔板结晶紫染色法检测各株菌生物膜的形成并用扫描电子显微镜(SEM)观察生物膜的形成情况。结果 ε-PL对ATCC25923和USA300的MIC均为31.25mg/mL。ε-PL浓度升高时对两株菌生长的抑制作用随之增强。1/2MIC ε-PL能显著降低ATCC25923和USA300生物膜的形成能力。 结论 ε-PL作为一种安全、高效的天然防腐剂,能有效抑制金黄色葡萄球菌细菌的生长及生物膜的形成,为新型药物的研发提供了理论依据。     

Amikacin-loaded vascular prosthesis as an effective drug carrier

Strong covalent immobilization of amikacin on Uni-Graft((R)) DV straight vascular prostheses made of gelatine-sealed poly(ethylene terephthalate) fibres was performed according to procedure described in the Polish Patent No. P-358934. The concentrations of amikacin in sample solutions were estimated either by HPLC or by UV spectroscopy method previously optimized for amikacin measurements. A high correlation was found between these two methods. It was found that the antibiotic was bound in mixed-type way via three types of interactions: strong covalent bonds (dominating amount: 81.84%) and weak interactions: physical adsorption and ionic bonds (18.19%). Even when total amount of physically and ionically attached drug has been released, the remaining covalently bound amount still locally protected the prostheses in vitro against bacteria. The release test was conducted in PBS at pH 7.4 at 37 degrees C and showed that about 15% of total drug amount was eluted from the matrix during the first 7 days of shaking, then no more antibiotic was released. It suggested that about 85% of amikacin attached to prosthesis modified in mixed-type mode was bound via covalent interactions. A bacterial inhibition test on Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853 showed inhibition of growth for all strains at low inoculum concentrations up to 30 days as well as high inoculum concentration for E. coli. At high concentrations of S. aureus and P. aeruginosa, the modified prostheses showed slight bacteriostatic effect since 10th day of experiment. Amikacin-modified vascular prostheses might therefore be protected against bacterial infection locally, without long-lasting drug release to human system.     

Synthesis and antibacterial activity of triphenyltinbenzoate

Triphenyltinbenzoate was synthesized using triphenyltinchloride and silver benzoate prepared from sodium benzoate. The structure of the synthetic compound was elucidated by spectral and C, H analysis. The antibacterial activities of the organotin compound were determined against four bacteria namely Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), Streptococcus pyogenes (clinical isolate) and Pseudomonas aeruginosa (ATCC 27853) in vitro experiment. All the bacteria were inhibited at a concentration of 200 μg/ml and 20 μg/ml in dimethylsulphoxide solution and the minimum inhibitory concentration was found to be same, 7.5 μg/ml for Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes and 10 μg/ml for Pseudomonas aeruginosa.     

微量平板稀释法测定血清杀菌活性的方法学研究

目的:采用微量平板稀释法测定血清杀菌活性(SBA)。方法:选择Mueller Hinton肉汤(MHB)为稀释剂、控制隔夜培养的菌悬液光度在108～109cfu/mL,以微量平板稀释法和琼脂平板计数法分别测定头孢哌酮钠对金黄色葡萄球菌ATCC25923,大肠埃希氏菌ATCC25922,铜绿假单胞菌ATCC27853三种标准质控菌的血清杀菌活性,并测定头孢哌酮钠对三种标准质控菌的SBA的天间和天内重现性。结果:微量平板稀释法与琼脂平板稀释法测定的结果相似,SBA中位数经秩和检验差异无统计学意义(P>0.05)。微量平板稀释法测定的结果天内、天间差异均无统计学意义。结论:微量平板稀释法测定SBA方法简便、易行,实验结果稳定、可靠,具有可行性。     

Extracellular and intracellular bactericidal activities of XF-70 against small-colony variant hemB mutants of meticillin-susceptible and meticillin-resistant Staphylococcus aureus

Small-colony variants (SCVs) of Staphylococcus aureus are phenotypic variants characterised by their small colony size and improved intracellular survival and are associated with persistent and relapsing infections. XF drugs are membrane-active, porphyrin-based antibacterial agents for topical administration, exerting rapid bactericidal activity against actively growing or resting, antibiotic-susceptible and multidrug-resistant strains of S. aureus. In this study, minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of XF-70 against isogenic, electron-transport deficient, SCV hemB mutants of one meticillin-susceptible S. aureus (MSSA) strain and one meticillin-resistant S. aureus (MRSA) strain were evaluated. Macrodilution MICs of XF-70 for MSSA strain 8325-4 and its hemB(+)-complemented derivative (0.5-1mg/L) were reproducible and were slightly higher than that for the SCV hemB mutant (0.25-0.5mg/L) and were not influenced by increasing inoculum size from 10(6) to 10(8) colony-forming units (CFU)/mL. MICs for MRSA strain COL, its SCV hemB mutant and hemB(+)-complemented derivative were equivalent (0.25-1mg/L). MBCs of XF-70 were ≤ 2-fold higher than MICs for all isolates. Extensive killing (≥ 4 log reduction in CFU/mL) was produced by 2mg/L XF-70 within 30 min against SCV hemB mutants both of 8325-4 and COL as well as their respective parent or hemB(+)-complemented derivatives. Pre-incubation of 10(7)CFU/mL of 8325-4 and its SCV hemB mutant with 5 × 10(6) polymorphonuclear neutrophils for 30 min markedly protected phagocytised organisms from rapid extensive killing by bactericidal levels (2mg/L) of subsequently added XF-70. The rapid bactericidal activity of XF-70 at low concentrations both against SCV and normally growing S. aureus is remarkable and represents an attractive potential for the treatment of persistent localised infections.     

微量接种菌落计数法测定抗生素后效应

建立微量接种菌落计数法测定体外抗生素后效应。方法：采用微量接种菌落计数法和经典的菌落计数法同时描记金黄色葡萄球菌ＡＴＣＣ２５９２３的生长动力曲线;两种方法同时测定环丙沙星、庆大霉素对ＡＴＣＣ２５９２２、ＡＴＣＣ２５９２３的抗生素后效应。结果：两种方法测定抗生素后效应的结果日内、日间差异无显著性（Ｐ＞０．０５）。结论：微量接种菌落计数法测定抗生素后效应较经典的菌落计数法操作简单、快速,且可节省人力、物力。     

亚胺培南／西司他丁的抗生素后效应及其影响因素的研究

研究亚胺培南／西司他丁的体外抗生素后效应（ＰＡＥ）及其影响因素。结果发现亚胺培南／西司他丁对常见感染致病菌金葡球菌、大肠埃希氏菌、铜绿假单胞菌、肺炎克雷伯氏菌能产生０．６～３．２ｈ的ＰＡＥ，以金葡球菌标准株最长；随着药物浓度增加及接触时间延长，ＰＡＥ延长，但有极限值，于１０ＭＩＣ～２０ＭＩＣ，接触２ｈ达最大值；亚胺培南／西司他丁与阿米卡星联用后ＰＡＥ呈半相加作用     

Efficacy of trovafloxacin in an in vitro pharmacodynamic simulation of an intraabdominal infection.

An in vitro model simulating trovafloxacin concentrations in human serum after standard doses was used to investigate the activity of this drug with time against Bacteroides fragilis, Escherichia coli, Enterococcus faecalis and Staphylococcus aureus. Antibiotic concentrations used for each incubation period were: 4.24 mg/l (0-1 h), 3.69 mg/l (1-3 h), 3.25 mg/l (3-6 h), 2.38 mg/l (6-8 h), 1.35 mg/l (8-24 h). A 99.9% initial inoculum reduction (> 3 log10 cfu/ml) was defined as bactericidal activity. Bactericidal activity against these organisms was obtained with trovafloxacin after the first hour of incubation, and similar activity was obtained against B. fragilis, E. faecalis and S. aureus after 3 h, when they were tested individually. When the strains were tested as mixed culture, there was bactericidal activity against E. coli after 1 h incubation and after 3 h for S. aureus. This activity was observed against B. fragilis and E. faecalis after 6 h incubation in the mixed culture assays and after 3 h when organisms were tested individually. Regrowth was not observed over a 24 h period. These data show that trovafloxacin might be effective in intraabdominal infections caused by mixed aerobic and anaerobic microorganisms.     

Growth of bacteria in intravenous fluids under stimulated actual-use conditions

The growth of microorganisms in nonnutritive intravenous solutions under simulated actual-use conditions was studied. Small quantities of Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae (final concentration 200-400 cells/ml) were injected into 500-ml containers (glass bottles and plastic bags) of 5% dextrose injection, 0.9% sodium chloride injection, and 5% dextrose and 0.9% sodium chloride injection. Additives (ampicillin, vitamin K, lidocaine, and vitamin B complex) were included in some i.v. solutions. Administration sets were attached to the i.v. containers, and the solutions were run into collection bottles; samples were withdrawn at 0, 1, 2, 3, 4, 5, 6, and 8 hours after contamination and plated for viable counts. Staph. aureus and K. pneumoniae remained viable in 5% dextrose injection and in 0.9% sodium chloride injection, but the numbers of these bacteria did not increase. The number of Ps. aeruginosa declined in all three solutions. In 5% dextrose and 0.9% sodium chloride injection, the number of K. pneumoniae declined but Staph. aureus maintained viability. The type of container and the drug additives had no effect on microbial growth, except that ampicillin was bactericidal to Staph. aureus. Low-level contamination of these bacteria in nonnutritive i.v. solutions under actual-use conditions does not result in large numbers of organisms within the time frame in which most solutions are administered.     

α-Helical domain is essential for antimicrobial activity of high mobility group nucleosomal binding domain 2 （HMGN2）

AIM: To examine the antimicrobial spectrum and functional structure of high mobility group nucleosomal binding domain 2 (HMGN2). METHODS: OMIGA protein structure software was used to analyze the two-dimensional structure of HMGN2. Synthetic short peptides were generated for studying the relationship between function and structure. Prokaryotic expression vectors were constructed for the holo-HMGN2 and its helical domain. Their E coli-based products were also prepared for antimicrobial testing. The antimicrobial assay included minimal effective concentration, minimal inhibitory concentration, and minimal bactericidal concentration. RESULTS: OMIGA protein structure software analysis revealed a transmembrane alpha-helical structure (the putative antimicrobial domain) located from position 18 to 48 of the HMGN2 protein sequence. The antimicrobial assay showed that the MIC of the recombinant holo-HMGN2 against E coli ML-35p (an ampicillin-resistance strain), Pseudomonas aeruginosa ATCC 27853 and Candida albicans ATCC 10231 were 12.5, 25, and 100 mg/L, respectively. Against the same microorganisms, the MIC of the synthetic HMGN2 alpha-helical domain were 12.5, 25, and 100 mg/L, respectively, that is, the same as with the recombinant form of HMGN2. In contrast, recombinant holo-HMGN2 was inactive against Staphylococcus aureus ATCC 25923. The synthetic N-terminal and C-terminal fragments of HMGN2 had no antimicrobial activity against E coli ML-35p, P aeruginosa ATCC 27853 or C albicans ATCC 10231. CONCLUSION: HMGN2 showed potent antimicrobial activity against E coli ML-35p, P aeruginosa ATCC 27853 and, to some extent, against C albicans ATCC 10231, but was inactive against S aureus ATCC 25923 in these assay systems. Itos alpha-helical structure may be essential for the antimicrobial activity of HMGN2.     

Synthesis and evaluation of antimicrobial activity of new 4-nitroso and 4-diazopyrazole derivatives.

Some N-(pyrazol-5-yl)-2-nitrobenzamides, variably substituted in the pyrazole nucleus as well as in the amidic group, were reacted in acetic acid media with potassium nitrite and hydrochloric acid. The different chemical behaviour of the reacted pyrazole derivatives in relation to the substitution pattern in both the pyrazole nucleus and the amidic group, was observed. All compounds isolated from the reaction mixtures (4-nitroso, 4-nitro, 4-diazo and 4-chloro derivatives) were evaluated by the agar diffusion method for their "in vitro" growth inhibitory activity against Candida albicans (our collection), Candida tropicalis ATCC 13803, Saccharomyces cerevisiae ATCC 36375, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853. The 1-methylpyrazole derivatives showed larger inhibition zones than the 1-phenyl ones in the antimicrobial tests.     

Evaluation of the MicroWorks, Inc. Swab Sampling System (MSSSTM) for Use in Performing Quantitative Swab Sampling

The purpose of this study was to qualify the MicroWorks, Inc. Swab Sampling System (MSSS?) swab kit for use in sampling cleanroom surfaces for bioburden. A six-part study was performed to demonstrate the suitability of the swab materials, the recovery of bioburden from typical cleanroom surfaces, the neutralization of typical disinfectants used in cleanrooms, the removal of diluents from the swabbed surface, and the hold time for test samples. A total of 13 challenge organisms were used: six National Collection of Type Cultures/American Type Culture Collection (NCTC/ATCC) standard culture organisms and seven environmental isolates, which were recovered from different MedImmune manufacturing facilities. Based on the results of the study it was shown that 12 of the challenge organisms were recovered from the calcium alginate swab materials and 13 of the challenge organisms were recovered from the sodium citrate diluent at ≥70%. Eleven organisms, including the six NCTC/ATCC organisms and five of the environmental organisms, were recovered from stainless steel, glass, polyvinylchloride curtain material, latex glove material, and neoprene at a rate of ≥70%. Effective neutralization was shown for LpH (an acid phenolic compound manufactured by Steris Corporation, Mentor, OH), Vesphene II, Spor-Klenz, 70% isopropyl alcohol (IPA), and Biocides B, X, and Y when utilizing the filtration/rinsing process. Recovery of six NCTC/ATCC organisms was demonstrated at ≥70%. The study also demonstrated that the diluents could easily be removed from the swabbed surface by following the swab with a 70% IPA wipe. A hold time of at least 24 h was demonstrated when samples were stored at 2-8 °C. The results of this study demonstrated that the MSSS? swab kit and qualified test method recover ≥70% of surface bioburden from common cleanroom surfaces in the presence of a wide variety of disinfectants.     

Synthesis and Biological Evaluation of Novel FtsZ‐targeted 3‐arylalkoxy‐2,6‐difluorobenzamides as Potential Antimicrobial Agents

Novel series of 3‐O‐arylalkylbenzamide and 3‐O‐arylalkyl‐2,6‐difluorobenzamide derivatives were synthesized and evaluated for their on‐target activity and antibacterial activity. The results indicated that the 3‐O‐arylalkyl‐2,6‐difluorobenzamide derivatives possessed much better on‐target activity and antibacterial activity than the 3‐O‐arylalkylbenzamide derivatives. Among them, 3‐O‐chlorobenzyl derivative 36 was the most effective in antibacterial activity (0.5, 4, and 8 μg/mL) against Bacillus subtilis ATCC9372, methicillin‐resistant Staphylococcus aureus ATCC29213, and penicillin‐resistant Staphylococcus aureus PR, while 3‐O‐methylbenzyl derivative 41 only exhibited the most potent activity (2 μg/mL) against Staphylococcus aureus ATCC25923.     

In vitro antibacterial activity of cefotaxime and desacetylcefotaxime, alone or in combination, against gram-positive cocci

The in vitro activity of cefotaxime and desacetylcefotaxime against Staphylococcus aureus, Staph. epidermidis and Streptococcus pyogenes was investigated. Synergy studies were performed using time-kill curves and the chequerboard test. The time-kill curves were performed on five strains each of Staph. aureus, Staph. epidermidis and Strep. pyogenes; cefotaxime and desacetylcefotaxime were tested alone or in combination at MIC and sub-MIC values. The chequerboard test was performed in microtitre plates on ten strains each of Staph. aureus, Staph. epidermidis and Strep. pyogenes: the results were interpreted by the fractional inhibitory concentration index. In some cases both methods showed synergistic interaction against the staphylococci tested. Indifference was observed against Strep. pyogenes.     

Activity of pulmonary vancomycin exposures versus planktonic and biofilm isolates of methicillin-resistant Staphylococcus aureus from cystic fibrosis sputum

Vancomycin is commonly used to treat methicillin-resistant Staphylococcus aureus (MRSA) infections in patients with cystic fibrosis (CF) lung disease. However, there are limited data to support the in vitro activity of this agent against MRSA isolated from CF sputum. The primary objective of this study was to evaluate the activity of vancomycin at pulmonary concentrations (intravenous and inhaled) against four clinical MRSA CF sputum isolates in planktonic and biofilm time–kill (TK) experiments. Vancomycin minimum inhibitory concentrations (MICs) were determined for these isolates at standard inoculum (SI) (~10⁶ CFU/mL) and high inoculum (HI) (~10⁸ CFU/mL) as well as in biofilms cultivated using physiological medium representing the microenvironment of the CF lung. Vancomycin concentrations of 10, 25, 100 and 275 µg/mL were evaluated in TK experiments against planktonic MRSA at varying inocula and versus biofilm MRSA. Vancomycin MICs increased from 0.5 µg/mL when tested at SI to 8–16 µg/mL at HI. Vancomycin MICs were further increased to 16–32 µg/mL in biofilm studies. In TK experiments, vancomycin displayed bactericidal activity (≥3 log₁₀ killing at 24 h) against 1/4 and 0/4 planktonic MRSA isolates at SI and HI, respectively, whereas vancomycin was bactericidal against 0/4 isolates against MRSA biofilms. Based on these findings, vancomycin monotherapy appears unlikely to eradicate MRSA from the respiratory tract of patients with CF, even at high concentrations similar to those observed with inhaled therapy. Novel vancomycin formulations with enhanced biofilm penetration or combination therapy with other potentially synergistic agents should be explored.     

Formulation Optimization of Chitosan-Stabilized Silver Nanoparticles Using In Vitro Antimicrobial Assay

Antimicrobial resistance at the infected site is a serious medical issue that increases patient morbidity and mortality. Silver has antibacterial activity associated with some dose-dependent toxicity. Silver nanoparticles, due to larger surface area, have antibacterial properties, which make them useful in the treatment of infections. Chitosan-stabilized silver nanoparticles (CH-AgNP) were formulated and evaluated for minimal inhibitory concentration and minimal bactericidal concentration testing against Staphylococcus aureus ATCC 29213, S aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, and 20 methicillin-resistant S aureus isolates. Minimum biofilm eradication concentration study was used to evaluate the biofilm reduction, and in vitro antimicrobial checkerboard assays were performed. The effective optimum ratio of AgNP:chitosan solution was 1:4. Minimal inhibitory concentration and minimal bactericidal concentration ranges of CH-AgNP were 4 to 14 times lower compared to AgNP alone against methicillin-resistant S aureus isolates. Minimum biofilm eradication concentration values of CH-AgNP for ATCC PA-01, P aeruginosa isolate 1, and P aeruginosa isolate 2 were found to be >84.59 μg/mL, 42.29 μg/mL, and 21.15 μg/mL, respectively. Thus, CH-AgNP is a potential formulation for wound treatment and management of infected sites associated with antimicrobial resistance.