Optimal timing for antimicrobial prophylaxis to reduce surgical site infections: a retrospective analysis of 531 patients.

It has been revealed that the administration of an antimicrobial prophylaxis (AP) reduces the rate of surgical site (SSI) following colorectal cancer surgery. Nevertheless, the optimal timing of this medication remains unclear. The aim of this study was to determine more precisely the optimal time for administering antibiotics and to see if this could reduce the number of possible surgical site infections. The files of individuals who underwent colorectal cancer surgery at the University Hospital Brandenburg an der Havel (Germany) between 2009 and 2017 were analyzed. Piperacillin/tazobactam, cefuroxime/metronidazole and mezlocillin/sulbactam were administered as AP regimens. Timing of AP was obtained. The primary objective was the rate of SSIs based on CDC criteria. Multivariate analysis took place to identify risk factors for SSIs. A total of 326 patients (61.4%) received an AP within 30 min, 166 (31.3%) between 30 and 60 min, 22 (4.1%) more than 1 h before surgery, and 15 (2.8%) after surgery. In 19 cases (3.6%) a SSI occurred during hospital stay. A multivariate analysis did not identify AP timing as a risk factor for the occurrence of SSIs. With significance, more surgical site occurrences (SSO) were diagnosed when cefuroxime/metronidazole was given. Our results suggest that AP with cefuroxime/metronidazole is less effective in reducing SSO compared with mezlocillin/sulbactam and tazobactam/piperacillin. We assume that the timing of this AP regimen of < 30 min or 30-60 min prior to colorectal surgery does not impact the SSI rate.

Population pharmacokinetics and dosing optimization of mezlocillin in neonates and young infants.

OBJECTIVES: Mezlocillin is used in the treatment of neonatal infectious diseases. However, due to the absence of population pharmacokinetic studies in neonates and young infants, dosing regimens differ considerably in clinical practice. Hence, this study aimed to describe the pharmacokinetic characteristics of mezlocillin in neonates and young infants, and propose the optimal dosing regimen based on the population pharmacokinetic model of mezlocillin. METHODS: A prospective, open-label pharmacokinetic study of mezlocillin was carried out in newborns. Blood samples were collected using an opportunistic sampling method. HPLC was used to measure the plasma drug concentrations. A population pharmacokinetic model was developed using NONMEM software. RESULTS: Ninety-five blood samples from 48 neonates and young infants were included. The ranges of postmenstrual age and birth weight were 29-40 weeks and 1200-4000 g, respectively, including term and preterm infants. A two-compartment model with first-order elimination was developed to describe the population pharmacokinetics of mezlocillin. Postmenstrual age, current weight and serum creatinine concentration were the most important covariates. Monte Carlo simulation results indicated that the current dose of 50 mg/kg q12h resulted in 89.2% of patients achieving the therapeutic target, when the MIC of 4 mg/L was used as the breakpoint. When increasing the dosing frequency to q8h, a dose of 20 mg/kg resulted in 74.3% of patients achieving the therapeutic target. CONCLUSIONS: A population pharmacokinetic model of mezlocillin in neonates and young infants was established. Optimal dosing regimens based on this model were provided for use in neonatal infections.

Compatibility and Stability of Ten Commonly Used Clinical Drugs in Pediatric Electrolyte Supplements Injection.

Objective: Pediatric electrolyte supplements injection is mainly used to supplement heat and body fluid, and commonly used in pediatrics. Its compatibility and stability with common clinical drugs such as antibiotics was rarely reported to ensure the children's safety and the rational use of drugs. The aim of the present study was to investigate physical and chemical stability of pediatric electrolyte supplements injection mixed with ten commonly used clinical drugs. Methods: According to clinical drug concentration, we mix the pediatric electrolyte supplements injection mixed with ten drugs. The compatible solutions were withdrawn at certain time intervals (0, 0.5, 1, 2, 4, 6 hours) after mixing and tested by description, insoluble particles detection, pH determination and high performance liquid chromatography (HPLC) assay of active ingredient as measures of physicochemical compatibility. Results: No obvious appearance changes were observed when mixing. Furthermore, over the 6 hours post-preparation period the pH values were within the requirements of each drug quality standard and the number of insoluble particles (≥10 and ≥25µm) met requirements of Chinese Pharmacopeia (Edition 2020) except for mezlocillin sodium for injection. The percentages of the initial concentrations maintained at a minimum of 97% in the mixtures within 6 hours. Conclusions: Nine commonly used clinical drugs remained stable in the pediatric electrolyte supplements injection for 6 hours at 25°C and avoiding from light. Mezlocillin sodium for injection was not recommended to be combined with electrolyte supplement injection for children because its insoluble particles exceed the standard.

Analysis of polymerized impurities in mezlocillin sodium and sulbenicillin sodium using two chromatographic separation mechanisms coupled to tandem mass spectrometry.

To effectively control the polymerized impurities in mezlocillin sodium and sulbenicillin sodium, a HPSEC method with TSK-gel G2000SWxl column and a RP-HPLC method with C18 analytical column were established to replace the classical gel filtration chromatography with Sephadex G-10 gel as stationary phase. By studying the chromatographic behavior of polymerized impurities in both methods with different chromatographic separation mechanisms, the polymerized impurities in mezlocillin sodium and sulbenicillin sodium were separated and detected effectively. The column switching two-dimension liquid chromatography ion trap/time-of-flight mass spectrometry was applied to characterize the structures of polymerized impurities eluted from the HPSEC method and RP-HPLC method for both drugs. The structures of the polymerized impurities in mezlocillin sodium and sulbenicillin sodium were deduced based on the MSn data. The results showed that the polymerized impurities detected by HPSEC method and RP-HPLC method were completely different. Therefore, two methods should be used meanwhile to control the polymerized impurities in mezlocillin sodium and sulbenicillin sodium.

Development and Validation of a UPLC-MS/MS Method for Ultra-Trace Level Determination of Acyl Chloride Potential Genotoxic Impurity in Mezlocillin.

3-Chlorocarbonyl-1-methanesulfonyl-2-imidazolidinone (CMI) is a critical intermediate used in the synthesis of mezlocillin drug substance and also a potential genotoxic impurity with acyl chloride moiety. The content of CMI in mezlocillin should be <0.16 ppm to avoid the carcinogenicity and mutagenicity threats to patients. Therefore, a workable determination of CMI was critically crucial for ensuring the safety of mezlocillin drug products. However, the conventional HPLC method is insufficient for detection limits at ppm or lower levels. Besides, the high activity of acyl chloride also raises a challenge to the direct measurement of CMI. Thus, we explored a simple esterification approach, which converts CMI into methyl 3-(methylonyl)-2-oxoimidazolidine-1-carboxylate completely by optimizing the reaction temperature and time. Furthermore, the selected reaction monitoring model of triple quadrupole mass spectrometer optimized by the Box-Behnken design significantly enhanced the sensitivity of ultra-trace level determination. The limit of detection and limit of quantification of the method were reached 0.014 and 0.02 ppm, respectively, in the following validation study. A sensitive and specific ultra-performance liquid chromatography tandem mass spectrometry method for ultra-trace level determination of acyl chloride potential genotoxic impurity in mezlocillin drug substance has been successfully established in this study, which will provide a practical quality control tool of mezlocillin.

Drug Repurposing for Candidate SARS-CoV-2 Main Protease Inhibitors by a Novel In Silico Method.

The SARS-CoV-2 outbreak caused an unprecedented global public health threat, having a high transmission rate with currently no drugs or vaccines approved. An alternative powerful additional approach to counteract COVID-19 is in silico drug repurposing. The SARS-CoV-2 main protease is essential for viral replication and an attractive drug target. In this study, we used the virtual screening protocol with both long-range and short-range interactions to select candidate SARS-CoV-2 main protease inhibitors. First, the Informational spectrum method applied for small molecules was used for searching the Drugbank database and further followed by molecular docking. After in silico screening of drug space, we identified 57 drugs as potential SARS-CoV-2 main protease inhibitors that we propose for further experimental testing.

Community-acquired pneumonia caused by methicillin-resistant Staphylococcus aureus in a Chinese adult: A case report.

RATIONALE: Methicillin-resistant Staphylococcus aureus (MRSA) has been established as an important cause of severe community-acquired pneumonia (CAP) with very high mortality. Panton-Valentine leukocidin (PVL) producing MRSA has been reported to be associated with necrotizing pneumonia and worse outcome. The incidence of community-acquired MRSA (CA-MRSA) pneumonia is very low, as only a few CA-MRSA pneumonia cases were reported in the last few years. We present a case of severe CAP caused by PVL-positive MRSA with ensuing septic shock. PATIENT CONCERNS: A 68-year-old male with no concerning medical history had developed a fever that reached 39.0°C, a productive cough that was sustained for 5 days, and hypodynamia. He was treated with azithromycin and alexipyretic in a nearby clinic for 2 days in which the symptoms were alleviated. However, 1 day later, the symptoms worsened, and he was taken to a local Chinese medicine hospital for traditional medicine treatment. However, his clinical condition deteriorated rapidly, and he then developed dyspnea and hemoptysis. DIAGNOSIS: CA-MRSA pneumonia and septic shock. The sputum culture showed MRSA. Polymerase chain reaction of MRSA isolates was positive for PVL genes. INTERVENTIONS: Mechanical ventilation, fluid resuscitation, and antibiotic therapy were performed. Antibiotic therapy included mezlocillin sodium/sulbactam sodium, linezolid, and oseltamivir. OUTCOMES: He died after 12 hours of treatment. LESSONS: This is a report of severe pneumonia due to PVL-positive CA-MRSA in a healthy adult. CA-MRSA should be considered a pathogen of severe CAP, especially when combined with septic shock in previously healthy individuals.

Pyoderma gangrenosum around an ileostoma: A case report.

RATIONALE: Pyoderma gangrenosum (PG) is a rare postoperative complication of enterostomy, mostly developing from dermatitis, which may have serious consequence. PATIENT CONCERNS: A patient with lower rectal cancer receiving low anterior resection (LAR) and protective ileostomy was initially diagnosed with dermatitis, which very quickly developed to PG, though no medical or familial history was found. DIAGNOSIS: We diagnosed the patient with peristoaml dermatitis starting from a tiny skin ulceration, but corrected the diagnosis to PG because of the rapid development and severe consequences. INTERVENTIONS: Routine stoma care did not improve the condition, so we performed 2 terms of debridement, the closure of the stoma and autologous skin transplantation before finally solving the problem. OUTCOMES: The patient was discharged 60 days after the first surgery and 5 days after the last one. After 18 months of follow-up, the patient kept in a stable condition. LESSONS: Medical staff should not neglect peristoaml dermatitis because of its common occurrence. Once the situation develops beyond the doctors' expectation, more efforts should be made to treat it, even expand debridement if possible.

Effects of prophylactic antibiotic therapy with mezlocillin plus sulbactam on the incidence and height of fever after severe acute ischemic stroke: the Mannheim infection in stroke study (MISS).

BACKGROUND AND PURPOSE: Fever after stroke is a strong predictor for a negative outcome with infections as the most common cause. The aim of this pilot study was to evaluate the effects of prophylactic antibiotic therapy on the incidence and height of fever after acute ischemic stroke. METHODS: This is a randomized, controlled study of antibiotic prophylaxis in patients with ischemic stroke enrolled within 24 hours from clinical onset who presented bedridden (modified Rankin score >3) with no significant infection. Interventions included prophylactic mezlocillin plus sulbactam (3 x 2 g/1 g for 4 days) or conventional management. Over 10 days, body temperature was continuously monitored, and the presence of infection was daily assessed. Primary end points were incidence and height of fever; secondary end points included rate of infection and clinical outcome. RESULTS: Sixty patients were included (mean, 75 years; median National Institutes of Health Stroke Scale score, 16). Over the first 3 days, patients in the intervention group showed lower mean body temperatures as well as lower daily peak temperatures (P<0.05). Throughout the observation period, 15 of 30 patients in the intervention group but 27 of 30 patients in the conventionally treated group developed an infection (P<0.05). Mean interval until the diagnosis of infection was 5.1 days in the intervention group and 3.3 days in the control group (P<0.05). Clinical outcome was more favorable in patients with prophylactic therapy (P=0.01). CONCLUSIONS: In patients with acute severe stroke, prophylactic administration of mezlocillin plus sulbactam over 4 days decreases body temperature, lowers the rate of infection, and may be associated with a better clinical outcome.

Antibiotic therapy for preterm premature rupture of membranes - results of a multicenter study.

AIMS: To evaluate whether primary application of mezlozillin in preterm premature rupture of membranes (pPROM) prolongs pregnancy and lowers neonatal morbidity. METHODS: In this prospective, randomized, double blind, placebo-controlled multicenter study a total of 105 pregnant women with pPROM between 24 + 0 and 32 + 6 weeks of gestation were examined receiving i.v. injections of corticoids and tocolytics as well as mezlocillin (3 x 2 g/d) or placebo. Assessed factors were prolongation of pregnancy and neonatal morbidity such as neonatal infection, respiratory distress syndrome (RDS), intraventricular hemorrhage (IVH) and necrotizing enterocolitis (NEC). RESULTS: Prolongation of pregnancy by more than 7 days was achieved in 63.8% of the mezlocillin group versus 44.8% of the placebo group (P < 0.05). The babies of mothers treated with anibiotics had fewer neonatal infections, RDS, IVH and NEC. Total morbidity was significantly lowered in the verum group (P = 0.02). CONCLUSIONS: Antibiotic administration following preterm premature rupture of membranes is associated with a prolongation of pregnancy and a reduction of neonatal infectious morbidity.

[Analysis of prophylactic antibiotics for cesarean section].

OBJECTIVE: To study the appropriate antibiotic for prophylactic use in cesarean section. METHODS: The effects and side effects of prophylatic antibiotics in 1 266 cesarean section were studied retrospectively. Six regiems were engaged: (1) Penicillin and Ampicillin; (2) Mezlocillin sodium; (3) Sulbactam and Ampicillin; (4) Ciprofloxacin; (5) Clindamycin; (6) Cefacidal. RESULTS: The duration of postoperative body temperature return to normal of 1 - 6 group is (54.0 +/- 28.4) hours, (48.9 +/- 27.8) hours, (49.9 +/- 23.9) hours, (58.6 +/- 33.7) hours, (52.5 +/- 25.2) hours, (63.1 +/- 51.1) hours respectively. It was longer in cefazolin group than the others. There were less puerperal morbidity and side effects of Mezlocillin. CONCLUSIONS: Penicillin and Ampicillin are still the most common choices as prophylatic antibiotic in cesarean section. Mezlocillin is appropriate as well.

Clinical determinants for the recovery of fungal and mezlocillin-resistant pathogens from bile specimens.

We conducted a retrospective analysis of all bile specimens obtained for routine cultures from January 1995 through December 1999 at our tertiary care hospital. Results of microbiologic testing were linked to clinical parameters gathered by means of chart review. A total of 722 isolates were cultured from 345 of 454 bile specimens obtained from 288 individual patients. Prior receipt of a >7-day course of antibiotics (odds ratio [OR], 5.7), extensive leukocytosis (leukocyte count, >20,000 cells/microL) on admission (OR, 7.8), endoscopic or percutaneous biliary manipulation during the previous 14 days (OR, 2.9), and treatment in an internal medicine ward (OR, 2.5) were independent factors significantly associated (Pless-than-or-eq, slant.05) with recovery of Candida species from bile specimens. Culture of mezlocillin-resistant bacteria from bile specimens was independently associated with the specimen having been obtained >1 week after admission (OR, 3.8), lack of history of endoscopic biliary drainage (OR, 3.2), and high serum aspartate aminotransferase levels (>72 U/L) on admission (OR, 2.6). Prospective studies are warranted to evaluate accordingly adjusted empiric therapies for biliary infections.

Efficacy of oral ofloxacin for single-dose perioperative prophylaxis in general surgery--a controlled randomized clinical study.

BACKGROUND: Perioperative antibiotic prophylaxis surely reduces surgical infection rate. Pharmacokinetic data of oral ofloxacin in combination with its antibacterial spectrum suggest effective protection against perioperative infection. In addition, costs, adverse effects, and induction of microbial resistance are low. Therefore we performed a controlled randomized study comparing oral and intravenous single dose prophylaxis. METHODS: A total of 61 patients undergoing colonic or pancreatic resection randomly received either a single dose standard intravenous prophylaxis or ofloxacin 400 mg and metronidazole 500 mg orally 2 h before surgery. Postoperative infections were recorded for 3 weeks. RESULTS: Groups were very well comparable regarding age, overweight, concomitant disease, type and duration of surgery, blood loss, and volume support. Infectious complications occurred in 14.8% after parenteral and 3.3% after enteral antibiotic prophylaxis. There was no difference in post-operative hospital stay. CONCLUSION: The data demonstrate that single-dose oral ofloxacin is at least as effective as a standard intravenous prophylaxis in patients with colonic or pancreatic resection. It offers significant advantages regarding costs and ease of administration.

Pharmacokinetic basis for oral perioperative prophylaxis with ofloxacin in general surgery.

BACKGROUND: Perioperative prophylaxis is recommended to be administered intravenously which, compared to oral prophylaxis, is more expensive. However, pharmacokinetic data on oral perioperative prophylaxis in patients with preoperative surgical and anesthesiological preparation are not available. PATIENTS AND METHODS: 40 patients with open hernial repair or cholecystectomy (low-risk group), colonic or pancreatic resection (high-risk group) received a standard single-dose perioperative prophylaxis with 4.5 g mezlocillin and 0.5 g metronidazole intravenously in addition to 400 mg ofloxacin orally 2 h prior to surgery. Antibiotic concentrations were measured perioperatively and pharmacokinetic data calculated. RESULTS: Serum and tissue concentrations of ofloxacin were above the MIC90 of the potential bacterial spectrum for surgical infection throughout the entire operation. Pharmacokinetic data were not influenced by preoperative surgical or anesthesiological preparation. CONCLUSION: Tissue and serum concentrations and the antibacterial spectrum of orally administered ofloxacin suggest effective protection against perioperative infection. Pharmacokinetic data confirm that oral ofloxacin may be used effectively as single-dose perioperative antibiotic prophylaxis. Since there are no clinical data comparing oral and intravenous singLe-dose prophylaxis, a prospective randomized clinical trial should be performed.

In vitro activity of mezlocillin, meropenem, aztreonam, vancomycin, teicoplanin, ribostamycin and fusidic acid against Borrelia burgdorferi.

The in vitro susceptibility profile of Borrelia burgdorferi is not yet well defined for several antibiotics. Our study explored the in vitro susceptibility of B. burgdorferi to mezlocillin, meropenem, aztreonam, vancomycin, teicoplanin, ribostamycin and fusidic acid. Minimal inhibitory concentrations (MICs) and minimal borreliacidal concentrations (MBCs) were measured using a standardised colorimetric microdilution method and conventional subculture experiments. MIC values were lowest for mezlocillin (MIC(90), < or =0.06 mg/l) and meropenem (MIC(90), 0.33 mg/l). Vancomycin (MIC(90), 0.83 mg/l) was less effective in vitro. Borreliae proved to be resistant to aztreonam (MIC(90), >32 mg/l), teicoplanin (MIC(90), 6.6 mg/l), ribostamycin (MIC(90), 32 mg/l), and fusidic acid (MIC(90), >4 mg/l). The mean MBCs resulting in 100% killing of the final inoculum after 72 h of incubation were lowest for mezlocillin (MBC, 0.83 mg/l). This study gathered further data on the in vitro susceptibility patterns of the B. burgdorferi complex. The excellent in vitro effectiveness of acylamino-penicillin derivatives and their suitability for the therapy of Lyme disease is emphasised.

Characterization of an In vitro-selected amoxicillin-resistant strain of Helicobacter pylori.

An amoxicillin-resistant (Amox(r)) strain of Helicobacter pylori was selected for by culturing an amoxicillin-sensitive (Amox(s)) strain in increasingly higher concentrations of amoxicillin, resulting in a 133-fold increase in MIC, from 0.03 to 0.06 microg/ml to 4 to 8 microg/ml. This resistance was stable upon freezing for at least 6 months and conferred cross-resistance to seven other beta-lactam antibiotics. beta-Lactamase activity was not detected in this Amox(r) strain; however, analysis of the penicillin-binding protein (PBP) profiles generated from isolated bacterial membranes of the Amox(s) parental strain and the Amox(r) strain revealed a significant decrease in labeling of PBP 1 by biotinylated amoxicillin (bio-Amox) in the Amox(r) strain. Comparative binding studies of PBP 1 for several beta-lactams demonstrated that PBP 1 in the Amox(r) strain had decreased affinity for mezlocillin but not significantly decreased affinity for penicillin G. In addition, PBP profiles prepared from whole bacterial cells showed decreased labeling of PBP 1 and PBP 2 in the Amox(r) strain at all bio-Amox concentrations tested, suggesting a diffusional barrier to bio-Amox or a possible antibiotic efflux mechanism. Uptake analysis of (14)C-labeled penicillin G showed a significant decrease in uptake of the labeled antibiotic by the Amox(r) strain compared to the Amox(s) strain, which was not affected by pretreatment with carbonyl cyanide m-chlorophenylhydrazone, eliminating the possibility of an efflux mechanism in the resistant strain. These results demonstrate that alterations in PBP 1 and in the uptake of beta-lactam antibiotics in H. pylori can be selected for by prolonged exposure to amoxicillin, resulting in increased resistance to this antibiotic.