In-depth analysis of the treatment effect and synergistic mechanism of TanReQing injection on clinical multi-drug resistant Pseudomonas aeruginosa.

Antibiotic resistance is a recognized and concerning public health issue. Gram-negative bacilli, such as Pseudomonas aeruginosa (P. aeruginosa), are notorious for their rapid development of drug resistance, leading to treatment failures. TanReQing injection (TRQ) was chosen to explore its pharmacological mechanisms against clinical multidrug-resistant P. aeruginosa (MDR-PA), given its antibacterial and anti-inflammatory properties. We revealed the expression of proteins and genes in P. aeruginosa after co-culture with TRQ. This study developed an assessment method to evaluate clinical resistance of P. aeruginosa using MALDI-TOF MS identification and Biotyper database searching techniques. Additionally, it combined MIC determination to investigate changes in MDR-PA treated by TRQ. TRQ effectively reduced the MICs of ceftazidime and cefoperazone and enhanced the confidence scores of MDR-PA as identified by mass spectrometry. Using this evaluation method, the fingerprints of standard P. aeruginosa and MDR-PA were compared, and the characteristic peptide sequence (Seq-PA No. 1) associated with flagellum was found. The phenotypic experiments were conducted to confirm the effect of TRQ on the motility and adhesion of P. aeruginosa. A combination of co-immunoprecipitation and proteome analysis was employed, and 16 proteins were significantly differentially expressed and identified as potential candidates for investigating the mechanism of inhibiting resistance in P. aeruginosa treated by TRQ. The candidates were verified by quantitative real-time PCR analysis, and TRQ may affect these core proteins (MexA, MexB, OprM, OprF, OTCase, IDH, and ASL) that influence resistance of P. aeruginosa. The combination of multiple methods helps elucidate the synergistic mechanism of TRQ in overcoming resistance of P. aeruginosa.IMPORTANCEPseudomonas aeruginosa is an opportunistic pathogen closely associated with various life-threatening acute and chronic infections. The presence of antimicrobial resistance and multidrug resistance in P. aeruginosa infections significantly complicates antibiotic treatment. The expression of ß-lactamase, efflux systems such as MexAB-OprM, and outer membrane permeability are considered to have the greatest impact on the sensitivity of P. aeruginosa. The study used a method to assess the clinical resistance of P. aeruginosa using matrix-assisted laser desorption ionization time of flight mass spectrometry identification and Biotyper database search techniques. TanReQing injection (TRQ) effectively reduced the MICs of ceftazidime and cefoperazone in multidrug-resistant P. aeruginosa (MDR-PA) and improved the confidence scores for co-cultured MDR-PA. The study found a characteristic peptide sequence for distinguishing whether P. aeruginosa is resistant. Through co-immunoprecipitation and proteome analysis, we explored the mechanism of TRQ overcoming resistance of P. aeruginosa.

Improvement of modified charcoal-cefoperazone-deoxycholate agar by supplementation with a high concentration of polymyxin B for detection of Campylobacter jejuni and C. coli in chicken carcass rinses.

Modified charcoal-cefoperazone-deoxycholate agar (mCCDA) was improved by supplementation with a high concentration of polymyxin B. The ability of the supplemented medium to isolate Campylobacter jejuni and C. coli from chicken carcass rinses was compared to that of Campy-Cefex agar and mCCDA. Modification of mCCDA with increased polymyxin B yielded a significantly (P < 0.05) higher isolation rate and greater selectivity than those achieved using Campy-Cefex agar and mCCDA.

Restoring the selectivity of Bolton broth during enrichment for Campylobacter spp. from raw chicken.

AIMS: When isolating Campylobacter spp. from retail raw chicken using BS EN ISO 10272-1:2006, contaminants frequently cause overgrowth on mCCDA plates. Therefore, these organisms proliferate in the enrichment medium, Bolton broth, indicating a lack of selectivity in this medium. This study sought to characterize the contaminant flora and to devise a modified Bolton broth to inhibit their growth. METHODS AND RESULTS: Contaminants (n=30) from separate samples were identified and antibiotic resistances determined. Most (93%) were extended spectrum ß-lactamase (ESBL) producing Escherichia coli, able to hydrolyse the cefoperazone present in Bolton broth and mCCDA. To inhibit these organisms, original formulation Bolton broth was supplemented with potassium clavulanate, at three concentrations, and recoveries of campylobacters from raw chicken were determined. Using standard Bolton broth, only 49% of samples (n=104) yielded campylobacters, but supplementation with 2 mg l(-1) potassium clavulanate increased this significantly (P<0.05), with 91% of samples positive. CONCLUSIONS: Potassium clavulanate can restore the selectivity of Bolton broth when isolating Campylobacter spp. from raw chicken. SIGNIFICANCE AND IMPACT OF THE STUDY: Raw chicken is often contaminated with the pathogen Campylobacter, but the ISO methodology for its detection is becoming compromised by the increasing presence of antibiotic-resistant bacteria. A simple modification ensures effective detection of this pathogen.

Therapeutic efficacy of cefpiramide and cefoperazone alone and in combination with gentamicin against pseudomonal infections in neutropenic mice.

Cefpiramide and cefoperazone alone and in combination with gentamicin were compared for therapeutic efficacy against pseudomonal infections in normal mice and in mice made neutropenic by administration of cyclophosphamide. Neutropenic mice were more susceptible to infection with Pseudomonas aeruginosa than normal mice. At all challenge doses, combination therapy with either cefpiramide-gentamicin or cefoperazone-gentamicin was more effective than that with a single agent. Therapy with the cefpiramide-gentamicin combination was significantly more active than that with the cefoperazone-gentamicin combination in protecting mice from fatal bacteremia. Pharmacokinetic studies in mice showed that cefpiramide attained a peak serum concentration of 12 micrograms/ml and a serum half-life of 40 min, which are higher than attained by cefoperazone with values of 4 micrograms/ml and 18 min. These factors may have caused the combined cefpiramide-gentamicin therapy to result in significantly improved survival rates in mice as well as in higher bactericidal titers than the cefoperazone-gentamicin combination. The results show that cefpiramide when combined with gentamicin is effective in treating serious infections with P. aeruginosa in neutropenic mice.

[In vivo antibacterial activity of cefoperazone in intraperitoneal infections in mice].

The in vivo antibacterial activity of cefoperazone (CPZ) against systemic infections was studied in comparison with that of cefotiam (CTM) using beta-lactamase non-producing bacteria and producing bacteria. In vitro antibacterial activity of CPZ against Gram-positive bacteria was slightly inferior to that of CTM, but there was no significant difference between their in vivo activities. On the other hand, the therapeutic effect of CPZ against Gram-negative bacteria was nearly parallel to in vitro antibacterial activity and particularly was superior to that of CTM against cephalosporinase (CSase) producing bacteria. The ascitic levels of CPZ in mice infected with CSase producing bacteria were persisted longer, but those of CTM disappeared quickly after administration. This result appeared to reflect on the therapeutic effects of both drugs.

[In vivo effects of cefoperazone in local infection].

The in vivo antibacterial activity and the penetration into inflammatory tissues of cefoperazone (CPZ) were compared with those of cefotiam (CTM) in local infection systems using mouse subcutaneous abscess and rat granuloma pouch. The serum levels of CPZ in subcutaneous abscess in mice caused by Staphylococcus aureus F-230 (penicillinase producing strain) were lower than that of CTM, but there was no significance between the therapeutic effects of both drugs. The same results were obtained using Staphylococcus aureus F-196 (penicillinase non-producing strain). When infected with Enterobacter cloacae H-27 (cephalosporinase producing strain) in rat granuloma pouch, the exudate levels of CTM were lower than those of CPZ. Judging from these results, it was suggested that CPZ was a useful antibiotic for the treatment of bacterial-inflammatory tissues.