In vitro susceptibilities of Bordetella pertussis and Bordetella parapertussis to seven fluoroquinolones.

The in vitro susceptibilities of Bordetella pertussis and Bordetella parapertussis to seven fluoroquinolones were assessed by the agar dilution method. Ciprofloxacin and temafloxacin were the most active compounds (MIC for 90% of isolates tested [MIC90], 0.06 microgram/ml), while enoxacin and pefloxacin were the least active (MIC90, 0.5 microgram/ml). Fleroxacin, lomefloxacin, and ofloxacin showed intermediate activities (MIC90s, 0.125 to 0.25 microgram/ml). These results suggest a possible role for the fluoroquinolones in the treatment of pertussis, at least in adult patients.     

In vitro susceptibilities of Bordetella pertussis and Bordetella parapertussis to four fluoroquinolones (levofloxacin, d-ofloxacin, ofloxacin, and ciprofloxacin), cefpirome, and meropenem.

The in vitro activities of levofloxacin, ofloxacin, d-ofloxacin, ciprofloxacin, cefpirome, and meropenem against 34 clinical isolates each of Bordetella pertussis and Bordetella parapertussis were determined by agar dilution on Mueller-Hinton agar supplemented with 5% horse blood. Levofloxacin was as active as ciprofloxacin against both species (MIC, 0.06 microgram/ml) and more active than ofloxacin and d-ofloxacin. Cefpirome was more active against B. pertussis (MIC, 1.0 microgram/ml) than against B. parapertussis (MIC, > 2 micrograms/ml), while the reverse was true for meropenem (MIC, 2.0 micrograms/ml against B. pertussis and 1.0 microgram/ml against B. parapertussis).     

In vitro susceptibilities of Borrelia burgdorferi to five oral cephalosporins and ceftriaxone.

We determined the in vitro susceptibilities of eight Borrelia burgdorferi isolates to five oral cephalosporins. MICs for B. burgdorferi 297 were 23 micrograms/ml (cephalexin), 45 micrograms/ml (cefadroxil), 91 micrograms/ml (cefaclor), 0.13 microgram/ml (cefuroxime), 0.8 microgram/ml (cefixime), and 0.02 microgram/ml (ceftriaxone). When B. burgdorferi isolates were exposed to concentrations twice the MIC of cefuroxime, cefixime, or ceftriaxone, at least 72 h of incubation was required to kill 99% of the organisms.     

In vitro activity of gemifloxacin and other antimicrobial agents against isolates of Bordetella pertussis and Bordetella parapertussis

We investigated the activity of the novel quinolone agent gemifloxacin (SB-265805) and a panel of comparator agents against Bordetella pertussis and Bordetella parapertussis. Erythromycin, azithromycin, ciprofloxacin and gemifloxacin were consistently active against both species. An azithromycin- and erythromycin-resistant B. pertussis isolate was not resistant to any of the other agents tested (gemifloxacin MIC < or =0.008 mg/L; ciprofloxacin, 0.015 mg/L; ampicillin, 2.0 mg/L; trimethoprim-sulphamethoxazole, 4.0 mg/L). The potency of ampicillin, azithromycin, erythromycin, ciprofloxacin and trimethoprim-sulphamethoxazole recorded against B. pertussis and B. parapertussis in this study was comparable to that noted in previous studies. However, MICs were generally higher than those noted in other trials; this may reflect the different methods used. Although in vitro data on the potency of gemifloxacin against B. pertussis and B. parapertussis have not previously been reported, these results are comparable to the potency of other quinolones against these pathogens. Should gemifloxacin achieve similar concentrations within the respiratory tract as other quinolones, this, coupled with its high in vitro potency, suggests that gemifloxacin has potential clinical efficacy in pertussis.     

Susceptibility of Bordetella pertussis and Bordetella parapertussis to 24 antibiotics

The susceptibility of Bordetella pertussis (28 strains) and Bordetella parapertussis (6 strains) to 24 antibiotics (penicillin and cephalosporin derivatives, erythromycin, josamycin, cotrimoxazole, imipenem, aztreonam and fosfomycin) was studied by means of the agar dilution method using charcoal horse blood agar. Piperacillin and mezlocillin showed the highest activity (MIC 0.0039-0.00781 micrograms/ml) against B. pertussis while B. parapertussis was most susceptible to piperacillin (0.03125-0.0625 microgram/ml), mezlocillin and latamoxef (0.125-0.25 microgram/ml).     

Utility of lipopolysaccharides from Bordetella pertussis and Bordetella parapertussis in the serodiagnosis of pertussis and parapertussis

Bordetella pertussis (Bp) and Bordetella parapertussis (Bpp), which are responsible for outbreaks of whooping cough in humans, are closely related, and it is difficult to discriminate between these species immunologically. We developed an immunodiagnostic method using an enzyme-linked immunosorbent assay (ELISA) or immunoblotting, on the basis of the serological differences between lipopolysaccharide (LPS) from Bp and Bpp. In ELISA, the sera from nine out of 11 patients with pertussis (about 80%) possessed high reactivities against whole cells (WC) of Bp in comparison with Bpp-WC, whereas the sera from five patients with the same disease (about 45%) reacted with Bp-LPS more than with Bpp-LPS. High reactivity against Bpp-WC and Bpp-LPS in the sera from 13 out of 16 patients with parapertussis (about 80%) was shown as compared with that against Bp-WC and Bp-LPS, respectively. Immunoblotting showed that all of the sera from pertussis patients reacted more strongly with Bp-LPS than with Bpp-LPS, except those which were unreactive. Almost all of the sera from parapertussis patients reacted with Bpp-LPS more than with Bp-LPS. These results indicated that immunoblotting, rather than ELISA, using LPS from Bp and Bpp is useful for serodiagnosis to distinguish between pertussis and parapertussis.     

In vitro susceptibility of Bordetella parapertussis to various antimicrobial agents.

The in vitro activity of 18 antimicrobial agents against 32 strains of Bordetella parapertussis isolated from whooping cough patients was studied. The most active antimicrobial agents were piperacillin and minocycline, followed (in descending order of activity) by moxalactam, erythromycin, cefoperazone, tetracycline, ampicillin, cefotaxime, chloramphenicol, josamycin, sulfamethoxazole, and nalidixic acid. Isolates were resistant to benzylpenicillin, cephalothin, cefatrizine, cefaclor, streptomycin, and cephalexin.     

Bordetella pertussis and Bordetella parapertussis infection in an Austrian pediatric outpatient clinic.

OBJECTIVE: To determine the proportion of children with an acute cough and laboratory evidence of Bordetella pertussis (B. pertussis) and B. parapertussis infection. METHODS: A prospective study was done, including children aged 0 months to 16 years who attended the outpatient clinic of the Innsbruck University Hospital between November 1995 and December 1998. Diagnosis of B. pertussis infection was made in children with acute cough using culture, PCR and serology; diagnosis of B. parapertussis infection was made with PCR and culture. RESULTS: Of the 183 children enrolled in the study, 71 (38.8%) had a B. pertussis infection. Of these, 7 (3.8%) were diagnosed using culture, 24 (13.1%) with culture and PCR, 30 (16.4%) with PCR alone, and in 10 (5.4%) children, a seroconversion of IgG or IgA against pertussis toxin (PT) was observed. The estimated incidence was 1,432 cases per 100,000 children with a cough. PCR enhanced the detection rate of B. pertussis infection 1.7-fold. The sensitivity of culture tests was 16.9%, and that of PCR 29.5%. Using a positive culture as gold standard, the sensitivity of PCR was 77.4% and its specificity 83.6%. In 1% (2/183) of the patients, an infection with B. parapertussis was only diagnosed with PCR. Positivity of culture, PCR and serology depended on age, disease duration and vaccination history. Of the patients with B. pertussis infection, 62% (44/71) had not been vaccinated and 11.2% were too young to have received the first recommended dose. CONCLUSION: Mainly non- or incompletely vaccinated infants are infected with B. pertussis. Improving the vaccination schedule and enhancing vaccination coverage is essential if infection is to be controlled in this population.     

In vitro susceptibilities of oral bacterial isolates to spiramycin.

Four hundred strains of oral bacteria were tested for their susceptibility to spiramycin. Actinobacillus actinomycetemcomitans and most species of Lactobacillus were resistant to the antibiotic. All strains of cariogenic Streptococcus mutans and most strains of bacterial species implicated in adult chronic periodontitis (Bacteroides gingivalis, B. intermedius, and Treponema denticola) were susceptible to spiramycin.     

Species differences in susceptibilities of Proteeae spp. to six cephalosporins and three aminoglycosides

Six cephalosporins and three aminoglycosides were examined for activity against 1,693 isolates belonging to six species of Proteeae. The most notable species-specific differences included the marked susceptibility of Providencia alcalifaciens and Proteus mirabilis to cephalothin, the resistance of Proteus vulgaris to cefamandole, and the resistance of Providencia stuartii to gentamicin and tobramycin. The third-generation cephalosporins cefotaxime and moxalactam were substantially more inhibitory than were cefoperazone, cefamandole, and cefoxitin. P. stuartii, generally the most resistant species, was, however, markedly susceptible to moxalactam and cefotaxime.     

Description of a multiplex Bordetella pertussis and Bordetella parapertussis LightCycler PCR assay with inhibition control

While culture for Bordetella species is highly specific, sensitivity is extremely variable due to patient age, immunization status, antibiotic treatment, and specimen transport conditions. We evaluated a real-time multiplex PCR assay as an alternative to culture for the detection and differentiation of Bordetella pertussis and Bordetella parapertussis. The PCR conditions allowed the simultaneous detection of one B. pertussis organism and five B. parapertussis organisms per reaction. An inhibition control was incorporated into the assay. Of 163 total samples evaluated, 37 of 38 samples positive by either culture or direct fluorescent antibody testing (DFA) were also positive by PCR (97% sensitivity). Of 125 culture- or DFA-negative samples, 101 were also negative by PCR (81% specificity). The described multiplex assay is a rapid, sensitive, contamination-limiting, real-time PCR assay that controls for inhibition. The assay performs well using liquid or swab samples and from dried material on slides.     

Direct detection of Bordetella pertussis and Bordetella parapertussis: comparison of polymerase chain reaction and culture

We evaluated the diagnostic performance of a genomic DNA amplification method for Bordetella pertussis and Bordetella parapertussis compared with culture isolation. Aliquots from B. pertussis and B. parapertussis cultures were added to sterile physiological saline or sterile distilled water to give bacterial suspensions of 10(8) cells/ml and serial dilutions were prepared. Suspensions in physiological saline were cultured on charcoal agar medium; bacterial growth was observed up to dilutions of 10(-7). Suspensions in distilled water were subjected to DNA extraction and nested polymerase chain reaction (PCR) was performed on the extracts; the PCR was positive up to dilutions of 10(-8) for B. pertussis and 10(-9) for B. parapertussis. Since the efficacy of culture isolation, regarded as the standard for the detection of B. pertussis and B. parapertussis, declines after the first stage of pertussis or with prior vaccination or antibiotic therapy, PCR, although not yet standardized, may provide an alternative diagnostic tool.     

Evolution of French Bordetella pertussis and Bordetella parapertussis isolates: increase of Bordetellae not expressing pertactin

Clin Microbiol Infect 2012; 18: E340-E346 ABSTRACT: Bordetella pertussis and Bordetella parapertussis are closely related bacterial agents of whooping cough. Whole-cell pertussis (wP) vaccine was introduced in France in 1959. Acellular pertussis (aP) vaccine was introduced in 1998 as an adolescent booster and was rapidly generalized to the whole population, changing herd immunity by specifically targeting the virulence of the bacteria. We performed a temporal analysis of all French B.?pertussis and B.?parapertussis isolates collected since 2000 under aP vaccine pressure, using pulsed-field gel electrophoresis (PFGE), genotyping and detection of expression of virulence factors. Particular isolates were selected according to their different phenotype and PFGE type and their characteristics were analysed using the murine model of respiratory infection and in vitro cell cytotoxic assay. Since the introduction of the aP vaccines there has been a steady increase in the number of B.?pertussis and B.?parapertussis isolates collected that are lacking expression of pertactin. These isolates seem to be as virulent as those expressing all virulence factors according to animal and cellular models of infection. Whereas wP vaccine-induced immunity led to a monomorphic population of B.?pertussis, aP vaccine-induced immunity enabled the number of circulating B.?pertussis and B.?parapertussis isolates not expressing virulence factors to increase, sustaining our previous hypothesis.     

In vitro susceptibilities of mycoplasmas and ureaplasmas to new macrolides and aryl-fluoroquinolones.

In vitro activities of the new macrolides clarithromycin, previously designated A-56268 (TE-031), and A-63075 and of the aryl-fluoroquinolones difloxacin (A-56619) and temafloxacin (A-62254) against 14 strains of Mycoplasma pneumoniae, 20 strains of Mycoplasma hominis, and 28 strains of Ureaplasma urealyticum were compared with that of erythromycin. All three macrolides inhibited growth of M. pneumoniae at less than 0.125 micrograms/ml. No macrolide was active against M. hominis. For five strains of U. urealyticum, MICs were greater than 256 micrograms/ml for all 3 macrolides. Excluding these, no other strain of U. urealyticum had an initial MIC of clarithromycin of greater than 1 microgram/ml, while five had initial MICs of erythromycin which were greater than 4 micrograms/ml. A-63075 was the least active of the three macrolides against ureaplasmas. Temafloxacin and difloxacin had similar activities against all three species, initially inhibiting 90% of M. pneumoniae strains at 2 and 8 micrograms/ml, 90% of M. hominis strains at 2 and 4 micrograms/ml, and 90% of U. urealyticum strains at 4 and 8 micrograms/ml, respectively. Additional pharmacokinetic and clinical trials with the new macrolides and quinolones with mycoplasmal or ureaplasmal infections are indicated.     

In vitro susceptibilities of zygomycetes to conventional and new antifungals

In vitro susceptibilities of 36 zygomycete isolates, belonging to six genera, to itraconazole, posaconazole, voriconazole, terbinafine, amphotericin B and 5-fluorocytosine were determined by using a broth microdilution adaptation of the National Committee for Clinical Laboratory Standards M-38P reference method. The influence of incubation time on MIC values, and the performance of a spectrophotometric method for MIC determination in comparison with the visual reference method, were also evaluated. Amphotericin B was active against most of the isolates. All the isolates were highly resistant to 5-fluorocytosine (MICs > 256 mg/L). Voriconazole was significantly less active than the other drugs with an overall MIC(90) (MIC at which 90% of the isolates were inhibited) of 32 mg/L. In contrast, posaconazole showed good activity (MIC(90) 1 mg/L). A wide range of MICs, from 0.03 to > or =32 mg/L, was obtained for itraconazole and terbinafine. Differences in susceptibility between and within genera were noted. Rhizopus spp. were significantly less susceptible to itraconazole, posaconazole, terbinafine and amphotericin B than Absidia spp., and less susceptible than Mucor spp. to amphotericin B. Terbinafine appeared to be more active against Rhizopus microsporus than against Rhizopus oryzae (geometric mean MIC of 0.15 and 64 mg/L, respectively). The activity of the drugs was dependent on the incubation period. A significant increase in MICs was noted between 24 and 48 h of incubation. On the other hand, the two methods used for MIC determination (visual and spectrophotometric readings) showed good agreement. These results suggest that the zygomycetes are a heterogeneous group for antifungal susceptibility. Some of the conventional and new antifungals are effective in vitro; their efficacies in vivo remain to be determined. The spectrophotometric method appears to be a valuable alternative to the visual method for MIC determination for zygomycetes.     

In vitro susceptibilities of Aeromonas hydrophila against new antibiotics.

The antibiotic susceptibilities of 16 clinical isolates of Aeromonas hydrophila obtained from cancer patients with septicemia were studied. Of the new beta-lactam antibiotics tested, azthreonam and moxalactam were the most active, followed by cefoperazone, cefotaxime, and ceftizoxime. Excellent activity was demonstrated by chloroamphenicol, tetracycline, aminoglycosides, and trimethoprim-sulfamethoxazole. Semisynthetic penicillins had no appreciable activity against this organism.     

In vitro susceptibilities of oral pigmented Bacteroides species to trospectomycin and other selected antimicrobial agents.

The in vitro activity of trospectomycin against 97 clinical isolates of oral pigmented Bacteroides species was compared with the activities of five other antimicrobial agents. At 4 micrograms/ml, more than 90% of isolates were inhibited by trospectomycin. Overall, strains that produced beta-lactamase (n = 41) were more resistant to trospectomycin, penicillin G, cefoxitin, piperacillin, and tetracycline but not to clindamycin. In this study, trospectomycin had excellent in vitro activity against oral pigmented Bacteroides species.