BACKGROUND AND OBJECTIVE

The human nasal passages host major human pathogens. Recent research suggests that the microbial communities inhabiting the epithelial surfaces of the nasal passages play a key factor in maintaining a healthy microenvironment by affecting both resistance to pathogens and immunological responses. Colonization of the nasal cavity by different pathogens such as Staphylococcus aureus and Klebsiella aerogenes, is associated with a higher postoperative infection morbidity. Povidone-iodine (PVP-I) as an antiseptic has been proven to display high antibacterial, antiviral, and antifungal properties even at low concentrations, and was shown to be effective in the control of infections to limit their impact and spread. It can be used as a topical antiseptic for skin decontamination and wound management, as a nasal spray, or as a gargle. There are different methods in testing the efficacy of potential antimicrobial suspensions. This study aimed to determine the concentration of PVP-I that is most effective in nasal decolonization using microsuspension test and colorimetric minimum inhibitory concentration (MIC) determination assays, resazurin microtiter assay (REMA), and Dey-Engley (D/E) neutralizer assay. The findings of this study will contribute to knowledge regarding the intended use of PVP-I in microbial control, particularly in bacterial infections.

Several dilutions (2.0%, 1.0%, 0.5%, 0.25%, 0.1% and 0.09%) of commercially bought 10% (10 mg per 100 ml) povidone-iodine were prepared and tested against a standardized inoculum (1x105) of Staphylococcus aureus and Klebsiella aerogenes at different contacttimes (5 seconds, 10 seconds, 30 seconds, 1 minute, and 5 minutes). Microdilution suspension test was performed to determine the log reduction per variable, while REMA and D/E neutralizer assay were used to determine the MIC. A value of greater than or equal to 5 log reduction was considered effective for microdilution suspension test. Estimates of agreement statistics were used to interpret the results of the assay in which the overall percent agreement (OPA), positive percent agreement (PPA), negative percent agreement (NPA), and Cohen’s kappa statistics were calculated.

Povidone-iodine concentration of 0.25% exhibited ?5 log reduction against K. aerogenes at the minimum contact time of 5 seconds. On the other hand,  a slightly higher PVP-I concentration was required to achieve ?5 log reduction for S. aureus at 0.5% concentration and a minimum contact time of 1 minute. There was an observed concordance of the results of REMA and D/E neutralizer as MIC colorimetric indicators, which yielded an overall test percent agreement of 90.30% (95% CI: 84.73–94.36), and a strong level of agreement (? = 0.8, pCONCLUSION

Low povidone-iodine concentrations (i.e., 0.5% against S. aureus and 0.25% against K. aerogenes) were observed to have bactericidal activity of at least 5 log reduction as rapid as the minimum contact time of 5 seconds. Furthermore, D/E and REMA, as colorimetric indicators, had comparable performance (OPA = 90.30%; ? = 0.8, p
Human ; Bacteria ; Povidone-iodine ; Microbial Sensitivity Tests ; Anti-infective Agents, Local ; Enterobacter Aerogenes ; Staphylococcus Aureus

This study investigated the application of poly(N-isopropylacrylamide)-based interpenetrating network temperature-sensitive hydrogels (notation: IPNT) as the delivery vehicle for phage endolysin Lys84 and the potential of drug-loaded hydrogels as antimicrobial materials. Interpenetrating network temperature-sensitive hydrogels were prepared by free radical polymerization of sodium alginate and N-isopropylacrylamide. Drug-loaded hydrogels (IPNT-Lys84) were obtained by dry soaking method with the endolysin Lys84 of Staphylococcus aureus phage. The physical properties of the hydrogels with and without drug loading were characterized by infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry. The swelling and deswelling of the hydrogels as well as the release of endolysin Lys84 were investigated. Moreover, the antibacterial properties of IPNT-Lys84 hydrogels at different temperatures and concentrations of the drug solution were studied. The results showed that IPNT-Lys84 hydrogel had uniform pores and a low critical solubility temperature (LCST) of 32 ℃. The equilibrium swelling of the hydrogel was 30 g/g, and the water loss rate was 88% upon deswelling. The release rate of endolysin reached more than 70% within 6 h at 37 ℃. The bactericidal rate of IPNT-Lys84 hydrogel was over 99.9%. The research results showed the feasibility of using IPNT to deliver the endolysin Lys84, and IPNT-Lys84 hydrogel might be an effective antimicrobial material against multi-drug resistant Staphylococcus aureus.
Hydrogels/chemistry* ; Bacteriophages ; Methicillin-Resistant Staphylococcus aureus ; Temperature ; Anti-Infective Agents

OBJECTIVE: To investigate the clinical characteristics and risk factors of acute leukemia complicated with multi-drug resistant bacterial septicemia in children. METHODS: The clinical data of children with acute leukemia complicated with septicemia admitted to the Affiliated Hospital of Guangdong Medical University from January 2013 to May 2021 were retrospectively analyzed. Their flora composition and drug resistance were also analyzed. The children were divided into multi-drug resistant bacteria (MDRB) group and non-multi-drug resistant bacteria (non-MDRB) group according to the drug sensitivity results, and the differences in clinical data between the two group were compared. RESULTS: A total of 108 children had drug sensitivity results, 47 cases in the MDRB group, including 26 strians of Gram-positive bacteria (G⁺), the most common multi-drug resistant G⁺ bacteria were coagulase-negative staphylococci (CoNS) and Staphylococcus aureus, and the most common multi-drug resistant Gram-negative bacteria G^- bacteria were Escherichia coli and Klebsiella pneumoniae subspecies pneumoniae. Compared with non-MDRB group, children in MDRB group had higher C-reactive protein (CRP) level and mortality rate (P <0.001, P =0.009), lower initial empirical anti-infection efficiency (P <0.001), and were more likely to have septic shock (P =0.003). Logistic analysis showed that the risk factors of acute leukemia complicated with MDRB septicemia in children were previous MDRB infection (OR =6.763, 95% CI: 1.141-40.092, P =0.035), duration of agranulocytosis before infection≥7 days (OR =3.071, 95% CI: 1.139-8.282, P =0.027), and previous use of antimicrobial drugs within 90 days before infection (OR =7.675, 95% CI: 1.581-37.261, P =0.011). CONCLUSIONS The clinical features of acute leukemia complicated with MDRB septicemia in children include a heavy inflammatory response, significantly elevated CRP, susceptibility to secondary septic shock, low efficiency of initial empirical anti-infective therapy, and high mortality rate. Previous MDRB infection, duration of agranulocytosis before infection≥7 days, and previous use of antimicrobial drugs within 90 days before infection are risk factors of acute leukemia complicated with MDRB septicemia in children.
Humans ; Child ; Shock, Septic ; Retrospective Studies ; Sepsis ; Risk Factors ; Bacteria ; Leukemia, Myeloid, Acute/complications* ; Acute Disease ; Escherichia coli ; Anti-Infective Agents ; Agranulocytosis

From the fungus Trichoderma sp., we isolated seven novel 18-residue peptaibols, neoatroviridins E-K (1-7), and six new 14-residue peptaibols, harzianins NPDG J-O (8-13). Additionally, four previously characterized 18-residue peptaibols neoatroviridins A-D (14-17) were also identified. The structural configurations of the newly identified peptaibols (1-13) were determined by comprehensive nuclear magnetic resonance (NMR) and high-resolution electrospray ionization tandem mass spectrometry (HR-ESI-MS/MS) data. Their absolute configurations were further determined using Marfey's method. Notably, compounds 12 and 13 represent the first 14-residue peptaibols containing an acidic amino acid residue. In antimicrobial assessments, all 18-residue peptaibols (1-7, 14-17) exhibited moderate inhibitory activities against Staphylococcus aureus 209P, with minimum inhibitory concentration (MIC) values ranging from 8-32 μg·mL^-1. Moreover, compound 9 exhibited moderate inhibitory effect on Candida albicans FIM709, with a MIC value of 16 μg·mL^-1.
Peptaibols/chemistry* ; Trichoderma/metabolism* ; Tandem Mass Spectrometry/methods* ; Anti-Infective Agents/pharmacology* ; Spectrometry, Mass, Electrospray Ionization/methods*

Aims: Murraya paniculata (L.) has been widely employed in medicine, has also been modified to serve as an ingredient in health foods and found application in cosmetics. This study was aimed to assess the biological activities of M. paniculata by analyzing the chemical compositions of its flowers, leaves and bark. Methodology and results: Crude extracts drawn from the flowers, leaves and bark of M. paniculata underwent testing to determine the antibacterial properties in terms of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), as well as the overall chemical composition, total phenolic content, flavonoids and antioxidant activity. Crude extract of leaves exhibited the most potent antibacterial activity when tested against Staphylococcus aureus TISTR 1466, Bacillus subtilis ATCC 6633 and Pseudomonas aeruginosa ATCC 27853. The crude extract from bark delivered the most significant antibacterial activity when tested against Micrococcus luteus TISTR 9341, Escherichia coli ATCC 1261, Pseudomonas sp., Streptococcus sp. and Methicilin resistant S. aureus (MRSA). For all crude extracts, the MIC value against M. luteus TISTR 9341 was 12.5 mg/mL. Meanwhile, the MBC value for the crude extract of leaves against B. subtilis ATCC 6633 was 12.5 mg/mL, whereas, for flower and bark crude extracts, the MBC value against S. aureus TISTR 1466 was 25 mg/mL. Antioxidant activity was at its highest for the crude extract from bark (IC50 = 1.36 mg/mL). The highest phenolic content was recorded for the crude extract from bark, while the highest flavonoid content came from the crude extract of leaves (70.81 ± 0.31 mgGAE/g extract and 115.73 ± 1.18 mgQE/g extract, respectively). Conclusion, significance and impact of study The research findings suggest that the crude extracts of M. paniculata leaves and bark show greater significant levels of bioactivity than was the case for crude extracts from flowers. The research findings could help in exploring the possibilities of using M. paniculata for pharmaceutical purposes and in aquaculture.
Murraya ; Anti-Infective Agents ; Phytochemicals

Indocyanine Green/therapeutic use* ; Photochemotherapy ; Combined Modality Therapy ; Anti-Infective Agents

This study aimed to identify the direct pharmacological targets of Jingfang Granules in treating infectious pneumonia via "target fishing" strategy. Moreover, the molecular mechanism of Jingfang Granules in treating infectious pneumonia was also investigated based on target-related pharmacological signaling pathways. First, the Jingfang Granules extract-bound magnetic nanoparticles were prepared, which were incubated with lipopolysaccharide(LPS)-induced mouse pneumonia tissue lysates. The captured proteins were analyzed by high-resolution mass spectrometry(HRMS), and the target groups with specific binding to the Jingfang Granules extract were screened out. Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis was used to identify the target protein-associated signaling pathways. On this basis, the LPS-induced mouse model of infectious pneumonia was established. The possible biological functions of target proteins were verified by hematoxylin-eosin(HE) staining and immunohistochemical assay. A total of 186 Jingfang Granules-specific binding proteins were identified from lung tissues. KEGG pathway enrichment analysis showed that the target protein-associated signaling pathways mainly included Salmonella infection, vascular and pulmonary epithelial adherens junction, ribosomal viral replication, viral endocytosis, and fatty acid degradation. The target functions of Jingfang Granules were related to pulmonary inflammation and immunity, pulmonary energy metabolism, pulmonary microcirculation, and viral infection. Based on the in vivo inflammation model, Jingfang Granules significantly improved the alveolar structure of the LPS-induced mouse model of infectious pneumonia and down-regulated the expressions of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6). Meanwhile, Jingfang Gra-nules significantly up-regulated the expressions of key proteins of mitochondrial function COX Ⅳ and ATP, microcirculation-related proteins CD31 and Occludin, and proteins associated with viral infection DDX21 and DDX3. These results suggest that Jingfang Gra-nules can inhibit lung inflammation, improve lung energy metabolism and pulmonary microcirculation, resist virus infection, thus playing a protective role in the lung. This study systematically explains the molecular mechanism of Jingfang Granules in the treatment of respiratory inflammation from the perspective of target-signaling pathway-pharmacological efficacy, thereby providing key information for clinical rational use of Jingfang Granules and expanding potential pharmacological application.
Animals ; Mice ; Lipopolysaccharides ; Pneumonia ; Inflammation ; Anti-Infective Agents ; Biological Assay ; Disease Models, Animal ; Interleukin-6

During the recent emergence of COVID-19, an increased practice of hand hygiene coincided with the reduced incidence of the norovirus epidemic in Japan, which is similar to experience with the pandemic flu in 2009. We investigated the relationship between the sales of hand hygiene products, including liquid hand soap and alcohol-based hand sanitizer, and the trend of norovirus epidemic. We used national gastroenteritis surveillance data across Japan in 2020 and 2021 and compared the base statistics of incidence of these two years with the average of the previous 10 years (2010-2019). We calculated the correlations (Spearman's Rho) between monthly sales of hand hygiene products and monthly norovirus cases and fitted them to a regression model. In 2020, there was no epidemic, and the incidence peak was the lowest in recent norovirus epidemics. In 2021, the incidence peak was delayed for five weeks to the usual epidemic seasons. Correlation coefficients between monthly sales of liquid hand soap and skin antiseptics and norovirus incidence showed a significantly negative correlation (Spearman's Rho = -0.88 and p = 0.002 for liquid hand soap; Spearman's Rho = -0.81 and p = 0.007 for skin antiseptics). Exponential regression models were fitted between the sales of each hand hygiene product and norovirus cases, respectively. The results suggest hand hygiene using these products is a potentially useful prevention method against norovirus epidemics. Effective ways of hand hygiene for increasing the prevention of norovirus should therefore be studied.
Humans ; Japan/epidemiology* ; COVID-19 ; Hand Hygiene ; Soaps ; Anti-Infective Agents, Local ; Norovirus

Marine microorganisms, especially marine fungi, have historically proven their value as a prolific source for structurally novel and pharmacologically active secondary metabolites (Deshmukh et al., 2018; Carroll et al., 2022). The corals constitute a dominant part of reefs with the highest biodiversity, and harbor highly diverse and abundant microbial symbionts in their tissue, skeleton, and mucus layer, with species-specific core members that are spatially partitioned across coral microhabitats (Wang WQ et al., 2022). The coral-associated fungi were very recently found to be vital producers of structurally diverse compounds, terpenes, alkaloids, peptides, aromatics, lactones, and steroids. They demonstrate a wide range of bioactivity such as anticancer, antimicrobial, and antifouling activity (Chen et al., 2022). The genetically powerful genus Emericella (Ascomycota), which has marine and terrestrial sources, includes over 30 species and is distributed worldwide. It is considered a rich source of diverse secondary metabolites with antimicrobial activity or cytotoxicity (Alburae et al., 2020). Notably, Emericella nidulans, the sexual state of a classic biosynthetic strain Aspergillus nidulans, was recently reported as an important source of highly methylated polyketides (Li et al., 2019) and isoindolone-containing meroterpenoids (Zhou et al., 2016) with unusual skeletons.
Animals ; Aspergillus nidulans ; Polyketides/chemistry* ; Anthozoa/microbiology* ; Anti-Infective Agents/pharmacology* ; Alkaloids

Four unreported monoterpene indole alkaloids, tabernaecorymines B-E (1-4), together with twenty-one known indole alkaloids (5-25) were obtained from the stem bark of Tabernaemontana corymbosa. Their structures and absolute configurations were elucidated by extensive spectroscopy, quantum chemical calculations, DP4+ probability analyses and Mo₂(OAc)₄-induced electronic circular dichroism experiment. The antibacterial and antifungal activities of these compounds were evaluated and some of them showed significant activity against Staphylococcus aureus,Bacillus subtilis, Streptococcus dysgalactiae and Candida albicans.
Tabernaemontana ; Anti-Infective Agents ; Antifungal Agents ; Anti-Bacterial Agents ; Indole Alkaloids