UNASSIGNED: This study aimed to investigate the antibacterial effects of plasma-activated saline (PAS) on My-cobacterium tuberculosis (Mtb).
UNASSIGNED: We conducted a growth assay on 3 strains of Mtb and an antibiotic sensitivity test on 4 strains of Mtb. Both tests included groups treated with normal saline (NS), PAS, and hydrochloric acid (HCl). The test of antibiotic sensitivity consisted of parallel tests with two concentrations of bacteria suspension: 10-2 and 10-4. The selected antibiotics were rifampicin (RIF), isoniazid (INH), ethambutol (EMB), and streptomycin (SM). The number of bacteria was determined after one month of culture under different conditions. The Kruskal-Wallis test was used to analyze the differences in grouping factors at representative time points.
UNASSIGNED: The growth assay indicated that PAS significantly inhibited the growth of 3 strains of Mtb compared with NS and HCl treatment groups. Furthermore, except for the initial observation time point, the remaining three observation time points consistently demonstrate no significant differences between the NS group and the HCl group. The antibiotic sensitivity test of INH, SM, and RIF indicated that PAS could inhibit the growth of antibiotic-resistant Mtb, and the antibiotic sensitivity test of INH and SM with bacterial suspension concentration of 10-2 and SM with bacterial suspension concentration of 10-4 showed statistically different results. The antibiotic sensitivity test of EMB indicated that the growth of Mtb in PAS was slower than that in NS and HCl in both antibiotic-resistant and sensitive Mtb, but there was no statistical difference.
UNASSIGNED: The study indicates that PAS contains a significant amount of active substances and exhibits high oxidizability and an acidic pH state. The unique physicochemical properties of PAS significantly delayed the growth of Mtb, compared to the NS and the HCl. PAS not only inhibited the growth of drug-sensitive strains but also significantly enhanced the sensitivity of drug-resistant strains to anti-tuberculosis drugs, which may provide a new therapeutic strategy for the treatment of tuberculosis.

OBJECTIVE: Current literature lacks consensus on risk factors for pharyngocutaneous fistula (PCF), and empirical antibiotic guidelines for PCF are limited. The aim of this study was to reduce the incidence of PCF and improve antibiotic treatment efficacy for patients with PCF after open neck surgery by analyzing their clinical characteristics, pathogenic bacteria, and antibiotic susceptibility.
METHODS: This study was a 13-year single-center retrospective cohort study, including 699 patients who underwent open neck surgery for laryngeal and hypopharyngeal cancer. Univariate and multivariate logistic regression analyses were conducted to identify the risk factors associated with the occurrence of PCF after surgery. The microbial species causing PCF were analyzed, and the antibiotic sensitivity of the top three pathogens was assessed. Venn diagrams were used to illustrate the antibiotics that exhibited 100% sensitivity against all three identified pathogens.
RESULTS: The incidence of PCF after open neck surgery was 8%. Logistic univariate and multivariate analyses revealed that flap reconstruction (OR = 3.62, 95% CI [2.02-6.52]), history of preoperative radiotherapy (OR = 2.01, 95% CI [1.31-2.73]), significant postoperative bleeding (OR = 1.79, 95% CI [1.11-2.69]), and history of diabetes (OR = 1.34, 95% CI [1.29-2.46]) were significantly associated with PCF occurrence. Among the 38 cases of PCF patients, the top three identified pathogens were Pseudomonas aeruginosa, Escherichia coli, and Enterobacter cloacae. The antibiotics cefepime, meropenem, ticarcillin/clavulanic acid, and cefoperazone/sulbactam showed 100% sensitivity against these top three pathogens.
CONCLUSIONS: Special attention should be given to patients undergoing open neck surgery, especially those with intraoperative flap reconstruction, a history of preoperative radiotherapy, postoperative bleeding, or diabetes. Strengthening monitoring and care is crucial in preventing the occurrence of PCF. According to antibiotic usage guidelines and considering the distribution of pathogens in PCF patients, empirical antibiotic treatment with cefoperazone/sulbactam or ticarcillin/clavulanic acid is recommended prior to obtaining susceptibility test results.

UNASSIGNED: This study aimed to elucidate the etiologies, microbiological profiles, antibiotic susceptibilities of bacteria and outcomes of patients with auricular perichondritis.
UNASSIGNED: This was a single-center retrospective study. Inpatients diagnosed with auricular perichondritis at a university teaching hospital in eastern China between January 2013 and December 2022 were included in this study.
UNASSIGNED: A total of 127 patients were enrolled, with an average age of 50.6 ± 16.9 years. In addition to cases in which the etiology remained undetermined in 37% of the patients, postoperative infection emerged as the predominant cause (37.8%), followed by trauma (18.1%). Among the 61 cultured isolates, 21.3% were gram-positive bacteria, 55.7% were gram-negative bacteria, and 23.0% were fungal isolates. The most frequent isolate was Pseudomonas aeruginosa (30/61, 49.2%). Notably, the incidence of fungal infections was markedly higher among postoperative patients than among post-traumatic patients (41.7% vs 7.1%, p = 0.03). The proportions of gram-negative bacteria (60.0% vs 50.0%) and fungal isolates (28.6% vs 15.4%) exhibited an increasing trend during the period of 2018-2022, as compared to the previous period of 2013-2017. The bacterial isolates exhibited high susceptibility to vancomycin (100%), amikacin (100%), cefepime (94.6%), and ceftazidime (90.9%). In contrast, overall susceptibility to fluoroquinolones was relatively low (65.2-67.4%), demonstrating a declining trend in the susceptibility of Pseudomonas aeruginosa. Notably, 78.7% of the patients received an initial treatment regimen covering Pseudomonas aeruginosa. Within 30 days of discharge, 8.5% (6/71) experienced an infection recurrence.
UNASSIGNED: Auricular perichondritis predominantly originates from iatrogenic (postoperative) infections. Antibiotic therapy covering Pseudomonas aeruginosa is a sensible and appropriate empirical treatment in the majority of patients with auricular perichondritis. However, increased resistance to fluoroquinolones has become a notable concern, suggesting the need to seek new, more aggressive strategies.

Metal nanoparticles (MNPs) have recently gained extensive attention due to their broad-spectrum prospect, particularly in biomedical application. Here, we reveal that long-term exposure to platinum nanoparticles (Pt NPs) increases the susceptibility of Pseudomonas aeruginosa PAO1 to imipenem and ciprofloxacin. We exposed PAO1 to Pt NPs (a series of doses, varying from 0.125 to 35 μg/mL) for 60 days and characterized the evolved strains (ES) and compared with wild type (WT) to understand the mechanism of heightened sensitivity. We found that overexpression of oprD and downregulation of mexEF-oprN facilitate the intracellular accumulation of antibiotic, thus increasing susceptibility. Furthermore, loss-of-function mutations were discovered in regulators lasR and mexT. Cloning intact lasR from wild-type (WT) into ES slightly improves imipenem resistance. Strikingly, cloning mexT from WT into ES reverts the imipenem and ciprofloxacin resistance to the original level. Briefly, the increase of membrane permeability controlled by mexT made PAO1 greatly susceptible to imipenem and ciprofloxacin, and the decrease of quorum sensing mediated by lasR made PAO1 slightly susceptible to imipenem. Overall, these results reveal an antibiotic susceptibility mechanism from prolonged exposure to MNPs, which provides a promising approach to prevent antibiotic resistance.

Citrobacter freundii, a common pathogen of freshwater fish, causes significant commercial losses to the global fish farming industry. In the present study, a highly pathogenic C. freundii strain was isolated and identified from largemouth bass (Micropterus salmoides). The pathogenicity and antibiotic sensitivity of the C. freundii strain were evaluated, and the histopathology and host immune response of largemouth bass infected with C. freundii were investigated. The results showed that C. freundii was the pathogen causing disease outbreaks in largemouth bass, and the infected fish showed typical signs of acute hemorrhages and visceral enlargement. Antimicrobial susceptibility testing showed that the C. freundii strain was resistant to Kanamycin, Medimycin, Clindamycin, Penicillin, Oxacillin, Ampicillin, Cephalexin, Cefazolin, Cefradine and Vancomycin. Histopathological analysis showed different pathological changes in major tissues of diseased fish. In addition, humoral immune factors such as superoxide dismutase (SOD), catalase (CAT) and lysozyme (LZM) were used as serum indicators to evaluate the immune response of largemouth bass after infection. Quantitative real-time PCR (qRT-PCR) was performed to investigate the expression pattern of immune-related genes (CXCR1, IL-8, IRF7, IgM, CD40, IFN-γ, IL-1β, Hep1, and Hep2) in liver, spleen, and head kidney tissues, which demonstrated a strong immune response induced by C. freundii infection in largemouth bass. The present study provides insights into the pathogenic mechanism of C. freundii and immune response in largemouth bass, promoting the prevention and treatment of diseases caused by C. freundii infection.

The microbial spectrum and antimicrobial resistance patterns change over time and vary across regions in patients with spontaneous bacterial peritonitis (SBP). There is an urgent need to clarify the factors associated with in-hospital mortality in these patients.
In this study, 377 patients with SBP and 794 patients with bacterascites were analyzed for the microbial spectrum, antimicrobial resistance profiles, and laboratory findings.
The most common pathogens were Escherichia coli (96, 25.5%), Staphylococcus epidermidis (55, 14.6%), and Enterococcus faecium (42, 11.1%). Multidrug-resistant (MDR) bacteria comprised 49.7% of gram-positive bacteria (GPB) and 48.8% of gram-negative bacteria (GNB). The most sensitive antibiotics were amikacin (91.5%), meropenem (89.8%) and piperacillin/tazobactam (87.6%). Extensively drug-resistant (XDR) (OR=51.457, p < 0.001), neutrophil count (OR=1.088, p < 0.001), and the model for end-stage liver disease (MELD) score (OR=1.124, p < 0.001) were independent predictive factors of in-hospital mortality in patients with SBP.
MDR represented nearly half of the bacteria isolated from patients with SBP, of which the high prevalence of extended-spectrum β-lactamase-producing and Carbapenem-resistant bacteria is concerning. The presence of XDR, higher MELD score, and neutrophil count were independent predictive factors associated with higher in-hospital mortality in patients with SBP, indicating that intensive care should be provided to these patients.

Acute rhinosinusitis (ARS) is one of the common diseases of upper respiratory tract infection in children. Bacterial infection is a significant aggravating factor in pediatric ARS. In this research, our goal was to detected the bacterial flora and antibiotic sensitivity of ARS in Chinese children.
We recruited 133 children with ARS between January 2020 and January 2022 from our hospital. Sinus secretion were collected and cultured for Gram stain as well as antimicrobial susceptibility tests.
Moraxella catarrhalis, Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae and Pseudomonas aeruginosa were detected in order in children with ARS, of which 25% were negative for bacterial culture and 10% were positive for two strains. Amoxicillin and clavulanate potassium were useful for Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis. Quinolones are useful for Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae and Pseudomonas aeruginosa.
This research updates the proportion of ARS bacterial infection in children in southern China and the antibiotic sensitivity.

With the development of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S ribosomal RNA (rRNA) gene sequencing, increasing numbers of new microorganisms are being discovered. In this report, Kerstersia gyiorum was isolated for the first time from the sputum of two elderly patients with neurodegenerative disease, and integrated traditional Chinese and Western medicine was used for treatment. The bacteria\'s growth characteristics, biochemical reaction characteristics, sensitivity to antibiotics, and the patients\' treatment are described, with a review of previous reports.

Streptococcus agalactiae (Group B Streptococcus, GBS) is a major cause of neonatal infections with high morbidity and mortality, and clindamycin is the main antibiotic used to treat GBS infections in patients allergic to penicillin. We aimed to analyse the antibiotic sensitivity, sequence types, serotypes, virulence factors, and antibiotic resistance mechanisms of clinically isolated clindamycin-resistant S. agalactiae and provide basic data for the treatment, prevention, and control of clinical infection of S. agalactiae. A total of 110 strains of clindamycin-resistant S. agalactiae were collected from two tertiary hospitals in Hebei, China. We performed antibiotic sensitivity tests for 11 antibiotics on these strains and whole-genome sequencing analysis. All the strains were susceptible to penicillin, ampicillin, linezolid, vancomycin, tigecycline, and quinupristin-dalfopristin. Resistance to erythromycin, levofloxacin, tetracycline, and chloramphenicol were also observed. Genome sequence analysis revealed that all strains belonged to 12 sequence types (STs) related to six cloning complexes (CCs), namely CC10, CC19, CC23, CC651, CC1, and CC17. Five serotypes were identified, including IA, IB, II, III, and V. The most prominent resistance genes were mreA (100%) and ermB (81.8%). Furthermore, cfb, cylE, pavA and the gene cluster related to the pili were 100% present in all strains, followed by lmb (95.5%) and srr1 (67.2%). This study found that clindamycin-resistant S. agalactiae showed polymorphisms in molecular types and serotypes. Furthermore, multiple virulence factor genes have been identified in their genomes.

Four Gram-staining-positive, aerobic, non-motile, circle-shaped bacteria were isolated from the faeces of bats (Rousettus leschenaultia and Taphozous perforates) collected from Guangxi autonomous region (E106°49\'20″, N22°20\'54″) and Yunnan province (E102°04\'39″, N25°09\'10″) of South China. Strains HY006T and HY008 shared highly 16S rRNA gene sequence similarity to those of Ornithinimicrobium pratense W204T (99.3%) and O. flavum CPCC 203535T (97.3%), while the strains HY1745 and HY1793T were closest to the type strains O. ciconiae H23M54T (98.7%), O. cavernae CFH 30183T (98.3%), and O. murale 01-Gi-040T (98.1%). Furthermore, when compared to the other members of the genus Ornithinimicrobium, the digital DNA-DNA hybridization and average nucleotide identity values of the four novel strains were within the ranges of 19.6-33.7% and 70.6-87.4%, respectively, both of which were below the respective recommended cutoff values of 70.0% and 95-96%. Significantly, strain HY006T was resistant to chloramphenicol and linezolid whereas strain HY1793T was resistant to erythromycin, clindamycin (intermediately), and levofloxacin (intermediately). The main cellular fatty acids (>20.0%) of our isolates were iso-C15:0 and iso-C16:0. Strains HY006T and HY1793T contained ornithine as the diagnostic diamino acid, also along with the alanine, glycine and glutamic acid in their cell wall. Based on phylogenetic, chemotaxonomic and phenotypic analyses, these four strains could be classified as two novel species of the genus Ornithinimicrobium, for which the names Ornithinimicrobium sufpigmenti sp. nov. and Ornithinimicrobium faecis sp. nov. are proposed. The type strains are HY006T (=CGMCC 1.16565T =JCM 33397T) and HY1793T (=CGMCC 1.19143T =JCM 34881T), respectively.