Objectives: We examined the spectrum of oral pathogens found in odontogenic abscesses and their susceptibility to penicillin as well as to amoxicillin with clavulanic acid, doxycycline, clindamycin and moxifloxacin. The in vitro results were compared with clinical observations. Patients and methods: One hundred and eighty eight swabs were obtained from 94 patients with odontogenic abscesses. Bacterial strains were isolated for susceptibility tests. The same patients were investigated for their clinical outcome after standard therapy. Results: A total of 517 bacterial strains were isolated from 94 patients. Ninety eight per cent of abscesses were polymicrobial. The most prevalent bacteria were Viridans streptococci representing 54% of the aerobic/facultative anaerobic bacteria. Prevotella spp. comprised 53% of the anaerobes. No multiresistant strains were detected. Susceptibility testing revealed a sensitivity of over 99% of aerobes/facultative aerobes and 96% of anaerobes sensitivity for moxifloxacin. The corresponding values for penicillin were lowest at 61% and 79%, respectively. In the clinical collective, patients with minor abscesses and no risk of further progression received surgical treatment without antibiotics (36%). Penicillin was administered additionally in 30%. Amoxicillin with clavulanic acid was given in 18% and clindamycin in 15%. Ninety two of the 94 patients showed significant recovery with the described treatment. Only in two cases was a change to the latest broader spectrum antibiotics necessary. Conclusion: In contrast to the moderate in vitro results, penicillin successfully treated the pathogens derived from odontogenic abscess sufficiently when adequate surgical treatment was provided. One third of the patients was treated successfully with incision and drainage only. We suggest that one good reason for its clinical efficacy is the susceptibility of the dominant aerobe/facultative aerobe and anaerobe strains to penicillin. (C) 2008 European Association for Cranio-Maxillofacial Surgery

OBJECTIVES:To test the bactericidal activity of human beta-defensins (hBDs) 2 and 3 against extended-spectrum beta-lactamase (ESBL)-producing Klebsiella strains.METHODS:Thirty-six Klebsiella pneumoniae and seventeen Klebsiella oxytoca ESBL-producing isolates from nosocomial infections were tested. The bactericidal activity of recombinantly synthesized hBD-2 and -3 was tested and the results were given either as lethal doses killing > or = 90% of bacteria (LD90s) or as MBCs (> or = 99.9% killing).RESULTS:Except for one intermediately susceptible strain (MBC = 25 mg/L), all other ESBL-producing strains were highly susceptible to both defensins (LD90s and MBCs < or = 12.5 mg/L).CONCLUSIONS:The results underline the high efficacy of hBD-2 and -3 against ESBL-producing Klebsiella, making both defensins attractive candidates as antimicrobial agents to combat these increasingly troublesome bacteria.

Fluoroquinolones are known to penetrate well into the infectious foci such as lung mucosa, epithelial lining fluid and alveolar macrophages achieving higher target site concentrations than the corresponding serum levels. In order to intergrate the in vitro antibacterial activity and pharmacokinetics of moxifloxacin and levofloxacin, their bactericidal efficacy was assessed by simulating human serum and lung tissue concentrations using Streptococcus pneumoniae, Staphylococcus aureus and Klebsiella pneumoniae as indicator organisms. The bacteria were exposed to fluctuating moxifloxacin and levofloxacin concentrations simulating the drug levels in serum, lung mucosa, epithelial lining fluid and alveolar macrophages. The following parameters were deduced from the kill curves: area under the bactericidal kill curve normalized to the initial inoculum (AUBKC norm), the time needed to reduce the inoculum by 3 log10 titers, and the initial bactericidal activity. In general, all these three parameters were for all the bacterial isolates having been exposed to moxifloxacin concentration dependent. In contrast, beyond a levofloxacin concentration of optimal bactericidal effect, higher drug concentrations did not further augment the bactericidal activity of levofloxacin. These data demonstrate that not all fluoroquinolones share the same pharmacodynamic targets needed to maximize their antibacterial effect.

Antibiotic activity against common respiratory pathogens can be affected by the pH of the medium (in vitro) or the bodily fluid (in vivo) in which bacteria are present. The ionized fraction of an antibiotic is not able to efficiently penetrate bacterial or mammalian membranes, reducing the quantity of molecules able to exert their antibacterial effect resulting in elevated MIC values This study shows that the activity of macrolide antibiotics is particularly sensitive to acidic conditions, whereas a ketolide and fluoroquinolones are much less affected. Furthermore, induction of spontaneous and multistep macrolide resistance is greatly increased in acidic medium. In contrast, telithromycin and moxifloxacin did not induce resistance at any pH. Antibiotics which are less likely to induce resistance in vitro may also be less likely to induce the development of resistance in patients with respiratory tract infections.

The ability of extended-spectrum β-lactamase (ESBL)-producing and non-ESBL-producing Klebsiella pneumoniae strains to induce a respiratory burst in polymorphonuclear leukocytes (PMNLs) was investigated. Ninety ESBL-producing and 178 non-ESBL-producing Klebsiella pneumoniae isolates were serotyped and their ability to induce a respiratory burst in PMNLs tested by monitoring the cells’ chemiluminescence (CL) response. The percentage of isolates inducing high levels of CL response (CL>75%) was significantly higher among non-ESBL producers (52%) than among ESBL producers (32.2%) (P<0.0001; OR=3.396; 95%CI=2.036–5.664). The median CL response was significantly higher among the non-ESBL producers (76.9%) than among the ESBL producers (52.6%) (P=0.034). The two groups did not differ in their ability to resist intracellular killing by PMNLs (P>0.05), with strains inducing high levels of CL response having significantly lower survival rates (31.8% vs. 42.4%) than strains inducing low levels of CL response (164% vs. 200%) (P<0.01). The frequencies of the K2 and the K25 serotypes were significantly higher among ESBL-producing strains (17.8% and 22.2%, respectively) than among the non-ESBL producers (6.2% and 1.7%, respectively) (P=0.0057 and P<0.0001). Of the 77 Klebsiella K serotypes, 71 were detectable among the non-ESBL producers, but only 24 were detectable among the ESBL producers. ESBL-producing Klebsiella pneumoniae strains might have a greater pathogenic potential by virtue of their ability to escape the phagocytic activity of PMNLs.

OBJECTIVES To investigate the in vitro activity of Extractum liquiritiae (EL), glycyrrhizic acid (GL), glycyrrhetinic acid (GA) and a novel lipophilic derivative of glycyrrhetinic acid monoglucuronide (GAMG), acetylated GAMG (aGAMG), against 29 Helicobacter pylori strains. METHODS The MIC of each compound was determined by the agar dilution method, and the killing kinetics were monitored in brain heart infusion broth ( approximately 10(6)-10(7) cfu/mL) at 0, 4, 24, 48, 72 and 96 h. RESULTS GA was the most potent compound (MIC(50 /90), 50/100 mg/L), inhibiting 79.3% of the strains at MIC < or =50 mg/L. Clarithromycin-resistant strains were susceptible at 12.5 and 25 mg/L, and metronidazole-resistant strains at 25-50 and at 200 mg/L. The MIC distribution (mg/L) of aGAMG was < or =6.25 (29.2%), 50 (4.2%), 100-200 (12.5%) and > or =400 (54.1%). EL and GL were less active (MICs >400 mg/L). GA exhibited rapid, concentration and strain-dependent bactericidal activity. CONCLUSIONS The potent in vitro activity of GA against H. pylori provides a further explanation for its beneficial effect on peptic ulcers. Its effectiveness against clarithromycin-resistant strains provides hope that it can form the basis for an alternative therapeutic agent against H. pylori.

ABSTRACT The aim of this study was to determine whether there is an association between serum resistance, O serotypes, and the production of extended-spectrum β-lactamases (ESBLs) in Klebsiella pneumoniae . Ninety ESBL-producing and 178 non-ESBL-producing K. pneumoniae isolates gathered in five European countries were O serotyped and tested for sensitivity to the serum's bactericidal effect. The frequency of serum-resistant isolates was higher among ESBL-producing strains (30%; 27/90 isolates) than among non-ESBL-producing strains (17.9%; 32/178 isolates) ( P = 0.037; odds ratio [OR] = 1.96; 95% confidence interval [95% CI] = 1.08 to 3.53). Although O1 was the most common O serotype in both Klebsiella groups, its frequency among ESBL-producing strains was significantly higher (59%; 53/90 isolates) than among non-ESBL producers (36%; 64/178 isolates) ( P = 0.0006; OR = 2.5; 95% CI = 1.52 to 4.29). Furthermore, the prevalence of the O1 serotype was higher among serum-resistant strains of both ESBL-producing (74%; 20/27isolates) and non-ESBL producers (75%; 24/32 isolates) than among serum-sensitive ESBL producers (52.4%; 33/63 isolates) and non-ESBL producers (27.4%; 40/146 isolates). Serum resistance among ESBL-producing strains (36%; 17/47 isolates) versus non-ESBL-producing strains (16%; 27/166 isolates) was also significantly higher after the exclusion of clonal strains ( P = 0.0056; OR = 2.9; 95% CI = 1.41 to 6.01). Sixteen ESBL types were detected, among which the frequency of serum resistance was significantly lower among the SHV-producing strains (9/48 isolates) than among the TEM producers (16/35 isolates) ( P = 0.016; OR = 3.65; CI = 1.3 to 9.7). Curing ESBL-coding plasmids did not influence the serum resistance of the bacteria; all six plasmid-cured derivatives maintained serum resistance. The present findings suggest that ESBL-producing strains have a greater pathogenic potential than non-ESBL-producing strains, but the linkage between O serotypes, serum resistance, and ESBL production remains unclear at this stage.

The composition of the human intestinal flora is important for the health status of the host. The global composition and the presence of specific pathogens are relevant to the effects of the flora. Therefore, accurate quantification of all major bacterial populations of the enteric flora is needed. A TaqMan real-time PCR-based method for the quantification of 20 dominant bacterial species and groups of the intestinal flora has been established on the basis of 16S ribosomal DNA taxonomy. A PCR with conserved primers was used for all reactions. In each real-time PCR, a universal probe for quantification of total bacteria and a specific probe for the species in question were included. PCR with conserved primers and the universal probe for total bacteria allowed relative and absolute quantification. Minor groove binder probes increased the sensitivity of the assays 10- to 100-fold. The method was evaluated by cross-reaction experiments and quantification of bacteria in complex clinical samples from healthy patients. A sensitivity of 10(1) to 10(3) bacterial cells per sample was achieved. No significant cross-reaction was observed. The real-time PCR assays presented may facilitate understanding of the intestinal bacterial flora through a normalized global estimation of the major contributing species.

AIMS:To examine the in vitro influence of various bacteria species on Helicobacter pylori (Hp) growth.METHODS AND RESULTS:The effects of 29 micro-organisms on 31 Hp strains were determined using two modified 'cross streak' methods. Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Morganella morganii, Serratia marcescens, Bacteroides fragilis, Fusobacterium nucleatum and Clostridium difficile showed the strongest inhibition. The inhibitory effects varied, depending on the bacteria spp. and Hp strains, and were method dependent. The cagA status of Hp strains did not correlate with the extent of inhibition.CONCLUSIONS:Helicobacter pylori is inhibited by a significant number of commensal bacteria species as well as opportunistic human pathogens. The success and progress of Hp infection may be influenced by the bacterial flora present, while the difficulty in cultivating Hp from the oral mucosa and faeces may be the result of antagonistic bacterial interaction.SIGNIFICANCE AND IMPACT OF THE STUDY:This study provides valuable data on the sensitivity of Hp to a variety of intestinal and oral commensals as well as opportunistic human pathogens. Hp's varying pathogenicity and the specific localization of infection may be the result of these sensitivities. These results can also serve as a basis for further studies to identify the inhibitory substances and make them available for therapeutic use.

The antibacterial activities of three newly developed fluoroquinolones (gatifloxacin, levofloxacin, and moxifloxacin) against a total of 307 gastrointestinal human isolates of Campylobacter jejuni and Campylobacter coli collected during 1980 to 1982 and 1997 to 2001 were examined and compared to those of ciprofloxacin and the unrelated antibacterial agents, clarithromycin, erythromycin, and tetracycline by using the agar plate dilution method. All of the fluoroquinolones exhibited a good activity against Campylobacter, and some of them were more active than ciprofloxacin, the macrolides, and tetracycline. Among the fluoroquinolones, gatifloxacin and moxifloxacin showed the highest anticampylobacter activity, with MICs at which 50% of the isolates tested are inhibited (MIC(50)s) and MIC(90)s of 0.125 and 4 microg/ml, respectively; the MIC(50) for both levofloxacin and ciprofloxacin was 0.25, and the MIC(90)s were 16 and 32 microg/ml, respectively. About 30% of the strains were found to be resistant to at least one fluoroquinolone. Resistance to gatifloxacin occurred in 9.8% of the isolates tested, and resistance to the other fluoroquinolones occurred in 19.9 to 27.4% of the isolates tested; the frequency of cross-resistance was 35.7 to 100%. An increase in fluoroquinolone resistance from 0% in 1980 to 1982 to 11.8 to 29% in 1997 and 1998, 8.2 to 31.8% in 1999 and 2000, and 12.1 to 30.3% in 2001 was found. A total of 61.4 to 73.2% of the C. jenuni strains resistant to erythromycin, clarithromycin, and/or tetracycline were susceptible to fluoroquinolones; gatifloxacin showed the highest percentage of inhibition. These results show that the newer fluoroquinolones with their potent activity could be used to treat infections with C. jejuni and C. coli. However, when these drugs are used, one must consider the increase in resistance and the high cross-resistance to these antimicrobial agents.

ABSTRACT The bactericidal activity of the novel beta-defensin hBD-3 against 28 species and 55 strains of gram-positive cocci and gram-negative fermentative and nonfermentative rods was tested. All strains proved to be highly or intermediately susceptible to hBD-3 (minimal bactericidal concentration [MBC], ≤50 μg/ml), except for Burkholderia cepacia , for all 23 tested strains of which MBCs were >100 μg/ml.

. Background: The aim of this study was to establish whether Chlamydia pneumoniae is implicated in the development of restenosis in patients with coronary heart disease (CHD) after percutaneous transluminal coronary angioplasty (PTCA). Patients and Methods: 67 patients were selected for study after they underwent control angiography after PTCA. Sera were tested for anti-chlamydial antibodies with a genusspecific ELISA and a species-specific microimmunofluorescence test (MIFT). Oropharyngeal specimens were examined for the presence of antigen with a Chlamydia immunofluorescence test (IFT), C. pneumoniae IFT and semi-nested PCR. In addition, anamnestic findings were also included. To determine the general level of antibodies, an age- and sexmatched control group of 180 persons was also examined for Chlamydia and C. pneumoniae serology. Results: Coronary angiography revealed that 31 of the 67 patients had developed a restenosis. There was no significant correlation between serological and angiographic findings. However, the MIFT showed a higher positive rate, especially in IgA, in the restenosis group. C. pneumoniae was detected in the oropharynx by PCR and/or IFT in 20.8% and 16.0% of the cases in patients with and without a restenosis. PCR found more C. pneumoniae -positive cases in the restenosis patients than IFT. No association was found between the detection of Chlamydia antigen and serology. The women with restenosis were more frequently smokers (p = 0.012). Men with restenosis were significantly older (p = 0.015). C. pneumoniae serology based on the rELISA or the MIFT did not show any correlation with restenosis. Conclusion: No evidence was found to suggest that positive C. pneumoniae serology is a risk factor for the development of restenosis. However, whether the species-specific serological test, especially for IgA-antibodies, and the detection of C. pneumoniae in oropharyngeal specimens by PCR might be reliable diagnostic markers in these cases remains to be determined.

Objective To establish a simple, fast, sensitive and specific method for the identification of human cytomegalovirus and the differentiation of glycoprotein B and H genotypes. Methods Based on the sequences of highly variable regions of glycoprotein H N-terminus(gH), glycoproteins B N-terminus(gBn) and the gB endoprotease cleavage site(gBclv), nested PCRs for the detection of HCMV were established. Nucleotide sequencing and PCR-assisted reverse hybridization assay using 17 specific oligonucleotide probes were performed and compared to differentiate gB and gH genotypes from 23 Chinese and 6 German transplant recipients with active HCMV infection. Results In Chinese patients, HCMV strains expressing the gH genotypes 1 and 2 and the gBn/gBclv genotypes 1,2 and 3 were identified. In addition to these genotypes, gBn/clv genotype 4 was also found in German but not in Chinese recipients. Both Chinese and German recipients co-infected with more than one genotype. Reverse hybridization was superior to nucleotide sequencing in detecting co-infections with different HCMV strains. Conclusion PCR-assisted reverse hybridization is a simple, fast and specific technique for identification of HCMV and the differentiation of glycoprotein B and H genotypes.

Surfactant protein D (SP-D) plays important roles in the regulation of innate immune responses in the lung. We have previously shown that SP-D can agglutinate and enhance the macrophage-dependent killing of specific unencapsulated phase variants of Klebsiella pneumoniae. In the present studies, we used 16 clinical isolates of Klebsiella representing four O-serotypes and examined the interaction of SP-D with their isolated LPSs. Although SP-D bound to the core oligosaccharide of rough LPS from all isolates, it selectively bound to smooth forms of LPS expressed by O-serotypes with mannose-rich repeating units in their O-polysaccharides. SP-D was more potent in agglutinating unencapsulated phase variants of O-serotypes expressing these SP-D “reactive” O-polysaccharides, and more effectively inhibited the adhesion of these serotypes to lung epithelial cells. This novel anti-adhesion activity required the multimerization of trimeric SP-D subunits (dodecamers). Klebsiella serotypes expressing “nonreactive” LPS O-Ags were isolated at a significantly higher frequency from patients with K. pneumoniae. Our findings suggest that SP-D plays important roles in the clearance of opportunistic Gram-negative bacteria and contributes to known serotypic differences in the pathogenicity of Klebsiella through specific interactions with O-polysaccharides.

Background: The cagA (cytotoxin-associated gene A) protein is found in about 50% of Helicobacter pylori strains; its clinical relevance in gastroduodenal disease is uncertain. Patients and Methods: The frequency of IgG antibodies to cagA was studied by using a commercial Western blot assay in sera of 189 patients with endoscopically and histologically confirmed gastroduodenal disease. In addition, 38 H. pylori strains isolated from biopsies were analyzed by immunofluorescence test (IFT) and PCR for detection of cagA protein and cagA gene sequences, respectively. Results: 54.3–60.0% of all patients with gastrointestinal diseases (chronic gastritis, gastric or duodenal ulcer and chronic duodenitis) and 28.6% with a normal mucosa were found to be positive for anti-cagA IgG antibodies. There was no significant difference in anti-cagA IgG seroprevalence between the different clinical entities. CagA-positive (cagA + ) H. pylori strains were detected in 44.7% and 50% of the 38 isolates by PCR and IFT, respectively. 22 of 23 patients infected with cagA + strains had anti-cagA antibodies. Using PCR as a gold standard, the sensitivity and specificity of the cagA IgG Western blot were 100.0% and 35.0%, respectively; the sensitivity and specificity of the cagA IFT were 76.5% and 71.4%, respectively. The incidence of the cagA + H. pylori strains detected either by PCR or IFT was significantly higher (p < 0.05 and p < 0.01, respectively) in patients with chronic duodenitis, gastric or duodenal ulcer compared to patients with chronic gastritis (66.7%, 80% and 30.4%, respectively). Conclusion: In this study the cagA-specific serological status in H. pylori infections as diagnosed by IgG Western blot was of no predictive value for severity of disease. In contrast, the cagA status of H. pylori isolates, diagnosed by IFT or PCR, was a predictive marker for severe disease and, therefore, also of clinical relevance in the assessment of the virulence of the infecting strain.

Welche pathogenen Mikroorganismen gibt es? Welche Veränderungen lösen sie im Körper aus? Wie werden die Erreger diagnostiziert, und welche therapeutischen Maßnahmen sind einzuleiten? Diese Fragen muß