Bactericidal activities of methoxyfluoroquinolones gatifloxacin and moxifloxacin against aerobic and anaerobic respiratory pathogens in serum

Mixed Vaginitis in the Third Trimester of Pregnancy Is Associated With Adverse Pregnancy Outcomes: A Cross-Sectional Study

Mixed vaginitis is a complex vaginal dysbiosis that differs from single vaginitis. Vaginitis in the third trimester may lead to adverse maternal and neonatal outcomes. The clinical characteristics, microbiological characteristics, and adverse pregnancy outcomes of mixed vaginitis in late pregnancy are worth studying. Therefore, this study investigated the clinical and microbiological characteristics of vaginitis and adverse pregnancy outcomes of patients with mixed vaginitis. We studied 1,674 women in late pregnancy who attended the Tianjin Medical University General Hospital from November, 2019 to October, 2021. We administered standardized questionnaires, performed vaginal examination and sampling plus microscope examinations, and assessed follow-up pregnancy outcomes. We cultured the vaginal discharge of the patients with mixed vaginitis to isolate pathogens and performed antimicrobial susceptibility tests of the isolated pathogens. For the patients with peripartum infection, we collected a sample to isolate pathogens. Among the 1,674 women, 66 (3.9%) had mixed vaginitis. The independent risk factor for mixed vaginitis in late pregnancy was a history of vaginitis during early and middle pregnancy (OR = 5.637, 95% CI: 3.314–9.580). The signs of vaginal erythema (63.6% vs. 42.0%), yellow discharge (81.8% vs. 59.6%), and malodor (31.8% vs. 18.8%) (P <0.05) were significantly higher in patients with mixed vaginitis than in patients with single vaginitis. Bacterial isolates of the vaginal secretions of patients with mixed bacterial vaginitis were mainly the pathogens of aerobic vaginitis and bacterial vaginosis, such as Gardnerella vaginalis, Streptococcus anginosus, and Staphylococcus epidermidis. Pathogen isolation of the vaginal secretions of patients with mixed fungus and bacteria vaginitis mainly included Candida albicans, followed by S. anginosus, Enterococcus faecalis, Staphylococcus hemolyticus, Staphylococcus aureus, Streptococcus agalactiae and Staphylococcus simulans. Women with mixed vaginitis had an increased incidence and risk of peripartum infections (6.1% vs. 1.4%, P <0.05; OR = 3.985, 95% CI:1.214–13.079). Escherichia coli is the main pathogen that causes peripartum infection. Mixed vaginitis in late pregnancy is characterized by a severe and complex phenotype, complex vaginal dysbiosis, and a long course of vaginal dysbiosis. This can lead to an increased incidence and risk of peripartum infection. Therefore, more attention should be paid to patients with mixed vaginitis in the third trimester of pregnancy.

Pharmacokinetics and Bioequivalence Study of a New Branded Generic Moxifloxacin Tablet Among Healthy Volunteers

A newly developed branded generic of a moxifloxacin (MOX) 400-mg tablet formulation was manufactured prior to this study. A bioequivalence (BE) study was done to assess the pharmacokinetics of the formulation using a randomized, open-label, 2-period crossover, 2-sequence, and single-dose experiment. Thirty healthy male volunteers were recruited. The test formulation, Flonoxin 400 mg, was compared with the reference formulation, Avelox 400 mg. The pharmacokinetic parameters of MOX were calculated based on the plasma drug concentration-time profile. Noncompartmental analysis was performed to determine its safety and tolerability. The 90% confidence intervals (CIs) were 88.5%-104.6%, 96.1%-101.1%, and 96.8%-100.7% for C_max , AUC_0-t , and AUC_0-inf , respectively. All CIs were within the 80.0%-125.0% boundary, thus fulfilling the acceptable BE criteria according to the ASEAN guidelines.

EUCAST expert rules in antimicrobial susceptibility testing

EUCAST expert rules have been developed to assist clinical microbiologists and describe actions to be taken in response to specific antimicrobial susceptibility test results. They include recommendations on reporting, such as inferring susceptibility to other agents from results with one, suppression of results that may be inappropriate, and editing of results from susceptible to intermediate or resistant or from intermediate to resistant on the basis of an inferred resistance mechanism. They are based on current clinical and/or microbiological evidence. EUCAST expert rules also include intrinsic resistance phenotypes and exceptional resistance phenotypes, which have not yet been reported or are very rare. The applicability of EUCAST expert rules depends on the MIC breakpoints used to define the rules. Setting appropriate clinical breakpoints, based on treating patients and not on the detection of resistance mechanisms, may lead to modification of some expert rules in the future.

Human serum activity of telithromycin, azithromycin and amoxicillin/clavulanate against common aerobic and anaerobic respiratory pathogens

Telithromycin is a new ketolide antimicrobial with a good in vitro activity against both aerobic and anaerobic respiratory pathogens. In this study, we evaluated the antibacterial activity over time of telithromycin (800mg), azithromycin (500mg), and amoxicillin/clavulanate (875/125mg) in serum following single oral doses of these agents to 10 healthy subjects. Inhibitory and bactericidal titers were determined at 2, 6, 12, and 24h after each dose and the median titer was used to determine antibacterial activity. Against two azithromycin-resistant strains of Streptococcus pneumoniae, both telithromycin (MIC=0.25 and 0.5 microg/mL) and amoxicillin/clavulanate exhibited inhibitory and cidal activity for at least 6h. All three antibiotics provided prolonged (>or=12h) inhibitory activity against strains of Hemophilus influenzae (telithromycin MIC=4.0 microg/ml). Both telithromycin and amoxicillin/clavulanate exhibited rapid and prolonged inhibitory activity (>or=12h) against each of the anaerobes studied (Finegoldia [Peptostreptococcus] magna Peptostreptococcus micros, Prevotella bivia, and Prevotella melaninogenica). Moreover, both agents provided bactericidal activity against both Prevotella species. In this ex vivo pharmacodynamic study, we found that telithromycin provided rapid and prolonged antibacterial activity in serum against macrolide-resistant strains of S. pneumoniae, beta-lactamase-positive and -negative strains of H. influenzae, and common respiratory anaerobic pathogens. These findings suggest that telithromycin could have clinical utility in the treatment of community-acquired mixed aerobic-anaerobic respiratory tract infections, including chronic sinusitis and aspiration pneumonia.

Are broad-spectrum fluoroquinolones more likely to cause Clostridium difficile-associated disease?

Limited evidence suggests that broad-spectrum fluoroquinolones such as gatifloxacin and moxifloxacin are more likely to cause Clostridium difficile-associated disease than levofloxacin. In a population-based case-control study of outpatients prescribed fluoroquinolones, we found no increased risk of C. difficile-associated disease requiring hospitalization among patients prescribed gatifloxacin or moxifloxacin compared to levofloxacin.

Fluoroquinolones and Anaerobes

The usefulness of fluoroquinolones for the treatment of mixed aerobic and anaerobic infections has been investigated since these agents started being used in clinical practice. Newer compounds have increased in vitro activity against anaerobes, but clinically relevant susceptibility breakpoints for these bacteria have not been established. Pharmacodynamic analyses and corroboration by new data from clinical trials have enhanced our knowledge concerning the use of fluoroquinolones to treat selective anaerobic pathogens. These studies suggest that newer agents could be useful in the treatment of several types of mixed aerobic and anaerobic infections, including skin and soft-tissue, intra-abdominal, and respiratory infections. The major concerns with expanding the use of fluoroquinolones to treat anaerobic infections have been reports of increasing resistance in Bacteroides group isolates and the impact of these antibiotics on the incidence of Clostridium difficile-associated disease.

Management of acute bacterial rhinosinusitis: current issues and future perspectives

Acute bacterial rhinosinusitis (ABRS), which manifests as an inflammation of at least one of the paranasal sinuses, is a major public health issue in developed countries. Diagnosis and treatment of ABRS can pose significant challenges in clinical practice, including difficulty in differentiation between viral and bacterial infection and a lack of simple, reliable and convenient methods for definitive diagnosis. Treatment choice is also a challenge because a decision is typically made empirically; therefore, the selection of therapy should be based on knowledge of local patterns of antimicrobial resistance, spectrum of activity against the most common ABRS pathogens (including those that are resistant to penicillins and macrolides) and pharmacodynamic potency. Current guidelines for diagnosis and treatment of ABRS in various countries share some similarities but also have important differences. Criteria for making the clinical diagnosis of sinusitis vary only slightly from country to country, while recommendations of therapy reflect the local impact of bacterial resistance.

Activity of moxifloxacin against Bacteroides fragilis and Escherichia coli in an in vitro pharmacokinetic/pharmacodynamic model employing pure and mixed cultures

The objective of this study was to determine the pharmacodynamic (PD) activity of moxifloxacin against four selected Bacteroides fragilis strains (three strains with low MICs and one strain with a high MIC) and two Escherichia coli strains (one strain with a low MIC and one strain with a high MIC) in a pharmacokinetic (PK) in vitro model in pure cultures as well as in mixed cultures. PK/PD assays of moxifloxacin were carried out with an initial maximum concentration of 4.0 mg l-1 and a half-life of 13 h. The E. coli strain with the low MIC was rapidly killed in both pure and mixed cultures in the in vitro PK/PD model, while the E. coli strain with the high MIC was not killed. None of the B. fragilis strains were rapidly killed in pure or mixed cultures. The bacterial numbers of the B. fragilis strains with low MICs were reduced by about one to two logs after 12 h in pure cultures. The presence of an E. coli strain with a low or a high MIC in the mixed culture reduced this effect even further.

Gatifloxacin: a review of its use in the treatment of bacterial infections in the US

Gatifloxacin (Tequin) is an 8-methoxy fluoroquinolone approved in the US for use in the treatment of community-acquired pneumonia (CAP), acute exacerbations of chronic bronchitis (AECB), acute sinusitis, uncomplicated and complicated urinary tract infections (UTIs), pyelonephritis, gonorrhoea and uncomplicated skin and skin structure infections. Gatifloxacin has a broad spectrum of antibacterial activity in vitro and good clinical and bacteriological efficacy in patients with indicated infections following once-daily administration by the intravenous or oral routes. It is generally well tolerated; the most common adverse events are associated with the gastrointestinal tract and CNS. Recent approvals for the use of gatifloxacin in the treatment of CAP due to multidrug-resistant Streptococcus pneumoniae (MDRSP) and in uncomplicated skin and skin structure infections extend the role of this drug in the treatment of bacterial infections in the US.

Genetic determinant of intrinsic quinolone resistance in Fusobacterium canifelinum

Fourteen fluoroquinolone-resistant fusobacterial strains, originating from cats or dogs, were characterized by sequencing of the 16S-23S and 16S rRNA genes and DNA-DNA hybridization and were described as a new species, Fusobacterium canifelinum. All of the strains are intrinsically resistant (MIC, >4 g/ml) to levofloxacin and other fluoroquinolones. Compared to the quinolone resistance-determining region (gyrA) of the susceptible relative F. nucleatum, we found that Ser79 was replaced with leucine and Gly83 was replaced with arginine.

Moxifloxacin: a review of its use in the management of bacterial infections

Moxifloxacin (Avelox) is a fluoroquinolone antibacterial with a methoxy group in the C-8 position and a bulky C-7 side chain. Moxifloxacin is approved for use in the treatment of acute exacerbations of chronic bronchitis (AECB), community-acquired pneumonia (CAP), acute bacterial sinusitis and uncomplicated skin and skin structure infections (approved indications may differ between countries). Moxifloxacin has a broad spectrum of antibacterial activity, including activity against penicillin-resistant Streptococcus pneumoniae. It achieves good tissue penetration and has a convenient once-daily administration schedule, as well as being available in both intravenous and oral formulations in some markets. Moxifloxacin has good efficacy in the treatment of patients with AECB, CAP, acute bacterial sinusitis and uncomplicated skin and skin structure infections, and is generally well tolerated. Thus, moxifloxacin is an important option in the treatment of bacterial infections.

The clinical significance of anaerobic bacteria in acute orofacial odontogenic infections

A review of the literature on orofacial odontogenic infections indicates that the underlying microflora is typically polymicrobial, predominantly involving strictly anaerobic gram-positive cocci and gram-negative rods, along with facultative and microaerophilic streptococci. Although no single species has been consistently implicated in all of these infections, the pathogenic potential of some of these organisms has been documented by many studies. This potential can be explained by a number of virulence factors demonstrated in anaerobic bacteria, as well as by synergistic interrelationships with other members of the infectious flora. Awareness of the anaerobic component of orofacial odontogenic infections dictates to a large extent the selection of antimicrobial therapy, mainly because of the frequency of beta-lactamase production by anaerobic gram-negative rods.

Serum Bactericidal Activity of the Methoxyfluoroquinolones Gatifloxacin and Moxifloxacin against Clinical Isolates of Staphylococcus Species: Are the Susceptibility Breakpoints Too High?

Healthy volunteers received a single dose of gatifloxacin and moxifloxacin (400 mg each), and serum samples were obtained from these volunteers over a 24-h period. Prolonged (> or =12 h) serum bactericidal activity (SBA) was observed for both agents against staphylococcal isolates with minimum inhibitory concentrations (MICs) of gatifloxacin of < or =0.5 mug/mL. In strains with gatifloxacin MICs of 1.0 mug/mL, SBA was observed for < or =6 h, and, for isolates with gatifloxacin MICs of 2.0 mug/mL, little or no SBA was observed for either drug. The relative lack of SBA against less susceptible strains of staphylococci suggests that the current susceptibility breakpoint concentration (MIC, 2.0 mug/mL) for these methoxyfluoroquinolones against Staphylococcus is too high.