Bacteroides Ureolyticus Research Articles

Bacteria trigger oxygen radical release and sperm lipid peroxidation in in vitro model of semen inflammation

To assess the in vitro effect of five bacterial strains isolated from semen samples (Escherichia coli, Staphylococcus haemolyticus, Streptococcus oralis, Bacteroides ureolyticus, and Ureaplasma urealyticum) on reactive oxygen intermediate (ROI) release and lipid sperm membrane peroxidation in the coincubated suspensions of white blood cells (WBC) with spermatozoa. An in vitro model of semen infection. Basic research laboratory. Healthy normozoospermic volunteers and healthy blood donors. None. Chemiluminescent assay was used to evaluate ROI generation by WBC. Malondialdehyde (MDA) concentration was determined in sperm lysates using high-performance liquid chromatography. Of the bacterial strains tested, B. ureolyticus, S. haemolyticus, and E. coli caused the greatest damage to sperm membrane lipids. An increase in MDA levels in sperm lysates was a natural consequence of bacteria-induced ROI generation. The WBC usually enhanced harmful activity of the infectious agent toward the cell membranes. The harmful effect of bacteria on spermatozoa depends on the type and species of microorganisms invading, colonizing, or infecting the male genital tract and is associated with the accompanying oxidative stress. The presence of leukocytes in semen appears to be the additional factor enhancing the sperm lipid membrane peroxidation, which may affect the fertility status.

Antimicrobial susceptibility of anaerobic bacteria in New Zealand: 1999–2003

Routine susceptibility testing of all anaerobic organisms is not advocated, but it is useful for laboratories to test periodically for anaerobic organisms and provide local susceptibility data to guide therapy. This study reports the national trend of antibiotic susceptibility of clinically significant anaerobes in New Zealand. Clinical isolates were tested using standardized methods against a range of antibiotics commonly used to treat anaerobic infections. Susceptibility was determined using NCCLS criteria. The change in susceptibility trends between this study and earlier studies was measured by comparing the geometric mean of the MIC. A total of 364 anaerobes were tested. Penicillin had poor activity against Bacteroides spp., Prevotella spp., Eubacterium spp., Clostridium tertium and Veillonella spp. In general, Fusobacterium spp., Bacteroides ureolyticus, Propionibacterium spp., Clostridium perfringens and anaerobic streptococci isolates, with the exception of Peptostreptococcus anaerobius, were penicillin susceptible. Amoxicillin/clavulanate showed good activity against most anaerobes, but resistance was seen with Bacteroides fragilis group and P. anaerobius isolates. Cefoxitin was more active than cefotetan, particularly against non-B. fragilis species, Eubacterium spp. and P. anaerobius. Meropenem and imipenem showed good activity against all anaerobes, with only 2 and 4% of Bacteroides spp., respectively, showing resistance. With the exception of Propionibacterium acnes isolates, which are predictably resistant, metronidazole was active against all anaerobes tested. There has been little change in susceptibility since 1997. Metronidazole, cefoxitin, piperacillin/tazobactam and amoxicillin/clavulanate remain good empirical choices when anaerobes are expected in our setting. No clinically relevant changes in susceptibility over time were found.

Microbiology of Intracranial Abscesses and Their Associated Sinusitis

To evaluate the organisms recovered from infected sinuses and associated intracranial abscesses (IAs). Retrospective review of findings from aspirate of pus from 10 infected sinuses and their corresponding IAs. Academic medical center. Ten patients diagnosed as having sinusitis (age range, 7-58 years). Aerobic and anaerobic bacteria findings from infected sinuses and IAs. Polymicrobial flora was found in 9 sinuses and 8 IAs. Anaerobes were isolated from all sinuses and 9 IAs. A total of 26 isolates (2.6 isolates per specimen) were recovered from the sinuses: 19 anaerobic, 6 aerobic or facultative, and 1 microaerophilic; 17 isolates were found in the IAs (1.7 isolates per site): 13 anaerobic, 2 aerobic or facultative, and 2 microaerophilic. The predominant anaerobes were Fusobacterium species (in 5 corresponding sinuses and abscesses, 1 in a sinus only, and 1 in an IA only), Prevotella species (in 3 corresponding sinuses and abscesses), Peptostreptococcus species (in 2 corresponding sinuses and abscesses, and 4 in a sinus only), Staphylococcus aureus, Haemophilus influenzae type b, microaerophilic streptococci, and Bacteroides ureolyticus (in 1 corresponding sinus and abscess each). Streptococcus pneumoniae was recovered 2 times, only from a sinus. Alpha-hemolytic streptococci and beta-hemolytic streptococci group F were each isolated once from the sinus. Concordance in the microbiological findings between the sinus and the IA was found in all instances. However, certain organisms were present at only one or the other site. These data illustrate the concordance in the recovery of organisms from infected sinuses and their associated IA and confirm the importance of anaerobic bacteria in sinusitis and IA.

Use of DNA hybridization to detect vaginal pathogens associated with bacterial vaginosis among asymptomatic pregnant women

The purpose of this study was to determine whether microbial DNA hybridization is a useful method to study bacterial vaginosis in asymptomatic pregnant women. Vaginal specimens were collected at <26 weeks' gestation from 230 women, and analyzed for bacterial vaginosis by both Gram stain using Nugent criteria and DNA hybridization for Gardnerella vaginalis, Prevotella bivia, Bacteroides ureolyticus, and Mobiluncus curtisii. Results were analyzed using McNemar's paired test and chi-square test for trend, with significance set at P < .05. By Gram stain, 60 (26.1%) of 230 were positive for bacterial vaginosis, and 134 (58.3%) were negative. By DNA hybridization, 99 (43%) were positive for at least 1 pathogen, and DNA results were significantly associated with Gram-stain results (P < .01). As the Nugent score progressed from normal to abnormal flora, the proportion with >1 pathogen detected by DNA hybridization increased significantly (P < .001). DNA hybridization may be a useful method to study shifts in vaginal flora during pregnancy.

Actinomycotic Vertebral Osteomyelitis With Spinal Cord Compression: A Case Report And Review Of The Literature

Actinomycotic Vertebral Osteomyelitis With Spinal Cord Compression: A Case Report And Review Of The Literature

Taxonomy of Campylobacter, Arcobacter, Helicobacter and related bacteria: current status, future prospects and immediate concerns.

The taxonomy of the genus Campylobacter has changed dramatically since its inception in 1963. At that time the genus comprised just two species. At present, taxa that were once assigned to Campylobacter may belong to one of over 50 species distributed among six genera. Most of these taxa belong to a phylogenetically distinct group referred to as either ribosomal RNA (rRNA) superfamily VI or the epsilon division of the class Proteobacteria. The taxonomic diversity of the group is matched by the diverse habitats in which they may be found, and by the wide range of diseases that they are associated with. Recognition of their clinical and economic importance has resulted in intense interest in the group, and the application of increasingly sophisticated isolation, detection and chemotaxonomic methods continues to elucidate new aspects of their biodiversity. However, despite the advances in new bacterial systematics, there remain a number of important issues concerning the classification of various campylobacterial taxa that require careful consideration. Ultimately, these issues are relevant to many working in the field of applied microbiology, including clinicians, veterinarians, epidemiologists and taxonomists. The purpose of this article is briefly to review the major developments in the taxonomy of Campylobacter from its inception to the present day; summarize the most recent changes in the field; analyse current topical issues of special relevance to applied microbiologists, including identification of the bacteria; and speculate on future prospects for campylobacterial taxonomy.

Vaginal indicators of amniotic fluid infection in preterm labor

Objective: To determine whether vaginal interleukin-6, interleukin-8, neutrophils, bacterial vaginosis, and selected vaginal bacteria are predictors of amniotic fluid (AF) infection among women in preterm labor. Methods: One hundred ninety-seven afebrile women in preterm labor with intact membranes had vaginal and AF samples collected for Gram stain, culture, and interleukin-8 and interleukin-6 determinations. Vaginal interleukin-6, interleukin-8, neutrophils, and vaginal flora were compared in women with positive and negative AF cultures. The negative AF culture group was subdivided according to AF interleukin-6 concentration. Logistic regression was used to examine the associations between vaginal cytokines and flora and AF infection or elevated AF interleukin-6. Results: The vaginal interleukin-8 concentration and neutrophil count were significantly higher with both AF infection and elevated concentrations of AF interleukin-6 and interleukin-8. The vaginal interleukin-6 concentration was not associated with AF infection or high concentration of AF cytokines. Amniotic fluid infection was associated with bacterial vaginosis or intermediate vaginal flora by Gram stain, absence of hydrogen peroxide–producing Lactobacillus, and presence of vaginal Bacteroides ureolyticus and Fusobacterium. Vaginal interleukin-8 levels greater than 30 ng/mL had 80% sensitivity and a positive predictive value of 35%, and an abnormal vaginal Gram stain (more than five neutrophils per 400× field, bacterial vaginosis species, or intermediate flora) had 90% sensitivity and a positive predictive value of 27% to detect AF infection or elevated AF interleukin-6. Conclusion: A high vaginal interleukin-8 concentration, abnormal vaginal Gram stain, absent hydrogen peroxide–producing Lactobacillus, and anaerobic vaginal flora were strongly associated with AF infection among women in preterm labor.

Induction of human immunodeficiency virus type 1 expression by anaerobes associated with bacterial vaginosis.

Bacterial vaginosis (BV) is a common disorder characterized by increased levels of anaerobic bacteria in the genital tract. BV has been associated with an increased rate of sexual transmission of human immunodeficiency virus (HIV). The effects of BV-associated anaerobic bacteria on HIV expression in monocytoid cells and T cells were examined. Peptostreptococcus asaccharolyticus and Prevotella bivia stimulated HIV expression in monocytoid cells, whereas Bacteroides ureolyticus, Peptostreptococcus anaerobius, and Lactobacillus acidophilus did not enhance HIV expression. P. asaccharolyticus also enhanced HIV expression in T cells and activated HIV long-terminal-repeat transcription in U38 cells. This report suggests a mechanism by which disturbances in vaginal flora could lead to a higher rate of sexual transmission of HIV. Furthermore, this study supports the idea that treatment of BV might serve as a preventive measure to reduce the risk of HIV transmission.

Antimicrobial susceptibility of non-Bacteroides fragilis group anaerobic Gram-negative bacilli in Europe

OBJECTIVE: To investigate the in vitro activity of a range of anti-anaerobe antimicrobials against non-Bacteroides fragilis group anaerobic Gram-negative bacilli isolated in Europe. METHODS: Isolates from 15 laboratories in 13 countries were identified by conventional methods. The MICs of 20 antibiotics were determined by an agar dilution method. RESULTS: There were 488 Prevotella spp., 174 fusobacteria, 69 Porphyromonas spp., 33 Bacteroides spp., 28 Bilophila wadsworthia and 16 Campylobacter spp. isolates, one Sutterella wadsworthensis isolate and four unidentified isolates. Penicillin resistance (and diminished susceptibility to piperacillin) was most common in Prevotella spp. and Bilophila wadsworthia but was also seen in many other species. All isolates, except three of Bilophila wadsworthia, were susceptible to amoxycillin/clavulanate. Most isolates were susceptible to cefoxitin (except Bilophila wadsworthia) and all were susceptible to the carbapenems. Clinafloxacin was the most active quinolone, followed by trovafloxacin and then sparfloxacin. Most fusobacteria were inherently resistant to the macrolides, as expected, but resistance to macrolides and a ketolide in other species was uncommon. Most Fusobacterium varium isolates were resistant to clindamycin, but resistance to clindamycin in all other species was rare. Tetracycline resistance was common but this did not affect the glycylcyclines. There was one isolate of Bacteroides putredinis resistant to chloramphenicol, and three isolates, a Bacteroides ureolyticus isolate, the Sutterella wadsworthensis isolate and one of the unnamed isolates, were metronidazole resistant. Rifampicin was active against most Prevotella and Porphyromonas spp., but not against many other genera. CONCLUSIONS: Penicillin resistance has increased in Europe among non-Bacteroides fragilis anaerobic Gram-negative bacilli, much of it due to beta-lactamase. Acquired resistance to other beta-lactams, macrolides and rifampicin has not significantly increased, and chloramphenicol and metronidazole are unaffected. However, resistance to tetracycline is common. The new compounds, a ketolide (HMR 3647), the glycylcyclines and clinafloxacin, are highly active.

Development and Clinical Application of a Polymerase Chain Reaction-Based Assay for Detecting Bacteroides ureolyticus

We developed a polymerase chain reaction (PCR)-based assay for detectingBacteroides ureolyticus. No DNA fragments hybridizing the internal probe specific forB. ureolyticus were amplified from the DNAs of other bacterial species tested. This assay can detect the amount of DNA corresponding to 18 cells ofB. ureolyticus. Using this assay, we examined urethral swab specimens from men with nongonococcal urethritis (NGU) and asymptomatic men for the presence ofB. ureolyticus. WhileB. ureolyticus was detected in 6 (12.0%) of 50 asymptomatic men, this was not significantly different from the detection rate of 19.3% (22 of 114 specimens) in men with NGU. This study demonstrates that the PCR-based assay can be applied for detectingB. ureolyticus in clinical specimens and suggests that this assay might develop into a useful tool for analyzing the pathogenicity of this organism in various organs.

Lactobacilli from Women With or Without Bacterial Vaginosis and Observations on the Significance of Hydrogen Peroxide

Lactobacilli are the predominant organisms in the healthy vagina whereas there are few or none in the vagina of women with bacterial vaginosis (BV). In a study of 155 women, these organisms were isolated from the vagina of 47 (88.6 per cent) of 53 healthy women, and from 30 (29.4 per cent) of 102 women with BV, the dominant species being L. acidophilus and L. plantarum . The proportion of hydrogen peroxide (H 2 O 2 )-producing strains of these two species, 31 (72 per cent) of 43 isolated from healthy women, was similar to the proportion of such strains, 14 (77 per cent) of 18 isolated from women with BV. Furthermore, the total number of H 2 O 2 -producing lactobacilli isolated from the healthy women, that is 38 (61 per cent) of 62 isolates of H 2 O 2 -producers, was not greatly different from 31 (73 per cent) of 42 isolates recovered from the women with BV. Overall, the number of colonies of lactobacilli isolated on Rogosa agar and the amount of H 2 O 2 produced by them were not much different whether the organisms were recovered from healthy women or women with BV. Bacteria-free supernates containing H 2 O 2 produced by growth of several strains of lactobacilli, in addition to micro-molar solutions of H 2 O 2 and known concentrations of lactic acid and urea, had no inhibitory effect on Bacteroides ureolyticus, Prevotella melaninogenica ( B. melaninogenicus ) and Bifidobacterium spp. However, Gardnerella vaginalis and Mobiluncus spp. were weakly-inhibited by the cell-free supernates and G. vaginalis by solutions of nitrate and catalase. As these organisms were also resistant to known concentrations of analytical H 2 O 2 , the positive inhibitory reaction from these fluids was probably due to an inhibitory substance in the supernate other than H 2 O 2 which deserves further investigation. These observations suggest that H 2 O 2 per se may be less bactericidal than previously thought in the control of intra-vaginal proliferation by BV-related bacteria in vivo . Keywords: lactobacilli, hydrogen peroxide, bacterial vaginosis, vaginal bacteria, inhibitory effect.

PCR-based technique for the detection of bacteria in semen and urine

Microorganisms associated with genito-urinary tract infections are often difficult to detect due to limitations associated with culture techniques. We have applied PCR-based detection of clinical isolates to complex sample matrices. Clinical isolates of Chlamydia trachomatis, Escherichia coli, Proteus vulgaris and Pseudomonas aeruginosa were grown, diluted and used to spike human urine and human semen. The urine and semen samples were centrifuged and the bacterial pellet was kept. A lysis buffer containing proteinase K, 8-methoxypsoralen and lauryl alcohol polyether was exposed to UV light to remove the bacterial DNA in the proteinase K, and was added to the bacterial pellet. After digestion, the proteinase K was destroyed and the lysates were subjected to 35 cycles of 16S rDNA amplification using a hot-starts technique and two primer pairs specific for eubacterial 16S rDNA: 8FPL-806R and 515FPL-13B. After amplification, the amplicons were cloned and sequenced to confirm amplification of the bacteria used to spiked the samples. We were able to detect as few as 10 5 bacteria per ml of urine or semen. Thirty unspiked semen samples were tested by PCR, and 17 were positive, including 10 samples negative by routine culture. The amplicons were cloned and sequenced for four PCR-positive/culture-negative semen samples: the 16S rDNA sequences obtained were mainly from strict anaerobes, including Prevotella spp. and Peptostrep-tococcus spp. Some 16S rDNA sequences were obtained that did not match any other 16S rDNA sequences available in various nucleic acid databases. Half of 14 unspiked urine sample tested were positive by PCR, including four samples negative by routine culture. Amplicons were cloned and sequenced for one urine sample showing only Lactobacillus spp. by routine culture, and sequences from Bacteroides ureolyticus, Clostridium spp., Corynebacterium urealyticum, Peptostrep-tococcus spp., and Lactobacillus acidophilus were found. These methods have great promise for the rapid detection of viable, but non-culturable bacteria in semen and urine. We are currently applying this technique for the detection of bacteria associated with idiopathic inflammatory conditions.

Sutterella wadsworthensis gen. nov., sp. nov., Bile-Resistant Microaerophilic Campylobacter gracilis-Like Clinical Isolates

Campylobacter gracilis (formerly Bacteroides gracilis) is an asaccharolytic, nitrate-positive, urease-negative organism that requires formate and fumarate or hydrogen as a growth additive and may pit agar media. Clinical isolates that were obtained primarily from appendiceal and peritoneal fluid specimens and initially were identified in our laboratory as B. gracilis were later found to include "unusual" strains that could be distinguished by biochemical and genetic criteria. These unusual C. gracilis strains were bile resistant, could not reduce tetrazolium chloride under aerobic conditions if formate and fumarate were added to the medium, and could grow in the presence of 2 or 6% oxygen if no blood was added to the medium. C. gracilis, other campylobacters, and the unusual strains produced distinctive dehydrogenase patterns when gels were incubated anaerobically. A cellular fatty acid analysis revealed that the cluster formed by the unusual organisms was distinct from the (separate) clusters formed by C. gracilis, Bacteroides ureolyticus, and other Campylobacter species. 16S rRNA sequence data indicated that these organisms are not related phylogenetically to either C. gracilis or other Campylobacter species; the most closely related taxa as determined by rRNA sequence analysis were unrelated aerobes (members of the genera Bordetella, Alcaligenes, Rhodocyclus, and Comamonas). DNA homology data confirmed that these taxa are separate groups. Our data indicate that the unusual organisms are members of a new genus and new species, for which we propose the name Sutterella wadsworthensis. The type strain of S. wadsworthensis is strain WAL 9799 (= ATCC 51579).

Lactobacilli from Women With or Without Bacterial Vaginosis and Observations on the Significance of Hydrogen Peroxide

Lactobacilli are the predominant organisms in the healthy vagina whereas there are few or none in the vagina of women with bacterial vaginosis (BV). In a study of 155 women, these organisms were isolated from the vagina of 47 (88.6 per cent) of 53 healthy women, and from 30 (29.4 per cent) of 102 women with BV, the dominant species being L. acidophilus and L. plantarum . The proportion of hydrogen peroxide (H 2 O 2 )-producing strains of these two species, 31 (72 per cent) of 43 isolated from healthy women, was similar to the proportion of such strains, 14 (77 per cent) of 18 isolated from women with BV. Furthermore, the total number of H 2 O 2 -producing lactobacilli isolated from the healthy women, that is 38 (61 per cent) of 62 isolates of H 2 O 2 -producers, was not greatly different from 31 (73 per cent) of 42 isolates recovered from the women with BV. Overall, the number of colonies of lactobacilli isolated on Rogosa agar and the amount of H 2 O 2 produced by them were not much different whether the organisms were recovered from healthy women or women with BV. Bacteria-free supernates containing H 2 O 2 produced by growth of several strains of lactobacilli, in addition to micro-molar solutions of H 2 O 2 and known concentrations of lactic acid and urea, had no inhibitory effect on Bacteroides ureolyticus, Prevotella melaninogenica ( B. melaninogenicus ) and Bifidobacterium spp. However, Gardnerella vaginalis and Mobiluncus spp. were weakly-inhibited by the cell-free supernates and G. vaginalis by solutions of nitrate and catalase. As these organisms were also resistant to known concentrations of analytical H 2 O 2 , the positive inhibitory reaction from these fluids was probably due to an inhibitory substance in the supernate other than H 2 O 2 which deserves further investigation. These observations suggest that H 2 O 2 per se may be less bactericidal than previously thought in the control of intra-vaginal proliferation by BV-related bacteria in vivo . Keywords: lactobacilli, hydrogen peroxide, bacterial vaginosis, vaginal bacteria, inhibitory effect.

Isolation of Bacteroides ureolyticus from vaginal discharge of mares.

A total of seven Bacteroides ureolyticus strains were isolated from the cervix and the clitoral fossa of mares with vaginal discharge. No other bacteria capable of causing metritis or vaginitis were isolated from the samples. The isolated strains resembled Taylorella equigenitalis. Both species are catalase, oxidase and alkaline phosphatase positive, but, in addition to these characteristics, B. ureolyticus strains produced urease and they could not tolerate 10% O2. They also failed to be agglutinated in a hyperimmune serum raised against T. equigenitalis; however, B. ureolyticus and T. equigenitalis were agglutinated in the slide agglutination test in a serum produced against one of the B. ureolyticus isolates. Further investigations are needed to clarify the pathologic role of B. ureolyticus in genital infections of mares and other animals.

Chemotaxonomic analyses of Bacteroides gracilis and Bacteroides ureolyticus and reclassification of B. gracilis as Campylobacter gracilis comb. nov.

The cellular fatty acids, respiratory quinones, and proteins of the generically misnamed taxa Bacteroides gracilis and Bacteroides ureolyticus were analyzed and compared with the corresponding chemotaxonomic features of their closest relatives, the campylobacters. Our results and previously published data for genotypic and phenotypic characteristics were used in a polyphasic approach to reconsider the classification of these organisms. We transfer B. gracilis to the genus Campylobacter as Campylobacter gracilis comb. nov. B. ureolyticus can be considered a campylobacter on genotypic grounds; in contrast, the proteolytic metabolism and fatty acid components of this taxon exclude it from the genus Campylobacter. We prefer to consider this taxon a species incertae sedis pending the isolation and characterization of additional B. ureolyticus-like bacteria.

Über die Standortflora der menschlichen Bindehaut: Untersuchungen von 135 Personen unterschiedlichen Alters

Conjunctival flora is a prime suspect in searching for the cause of post-traumatic or post-operative ocular infections. Better information on its individual composition is therefore desirable. 135 persons (66 women, 69 men) were examined during a period of 1 1/2 years. The youngest patient was 3 years old, the oldest 90. Both eyes of all patients were examined. Megasphaera elsdenii, Bacteroides ureolyticus, Bacteroides pneumosintes, Stomatococcus mucilaginosus, and group ANF Corynebacterium were isolated for the first time in the eye by this study. The latter was found so often that it can be ascribed the role of an aerobic indicator organism. Characteristic changes appear in the conjunctival flora at different stages of life. In particular, for example, the species spectrum of aerobic bacteria broadens with advancing age, and the population of aerobic bacteria increases in density. With increasing age aerobic cocci are found less frequently in favor of the Corynebacteria. The proportion of anaerobic cocci increases among the anaerobes, while Propionibacteria are demonstrated less frequently. The significance of the organisms found in conjunctiva by this study for the first time is still unclear. No qualitative or quantitative sex-specific influence on the development of conjunctival flora was found.

Analysis of intestinal flora of a patient with congenital absence of the portal vein

A 14-year-old female patient, admitted for a closer examination of liver tumour (hepatocellular adenoma), was diagnosed as having a congenital absence of the portal vein. The blood ammonia level (approximately 120 μg dl −1) in the superior mesenteric vein was markedly low compared to the normal value of 300–350 μg dl −1 in the portal vein. The decreased ammonia concentration and urease activity of the patient's faeces were demonstrated. The dominant intestinal flora in the faeces of the patient, before operation, was Bifidobacterium sp., Bifidobacterium breve, Bifidobacterium lonqum, Lactobacillus plantarum, and after the operation Bacteroides vulgatus, Veillonella parvula, Peptococcus magnus Bifidobacterium longum. In contrast, Bifidobacterium bifidum, Bacteroides ureolyticus, Bacteroides ovatus and Bacteroides distasonis, B. ovatus, Bifidobacterium adolescentis were dominant flora in the faeces of two healthy volunteers, respectively. Among microorganisms isolated from the patient, Morganella morganii, Candida sp., Eubacterium aerofacience and Eubacterium rectale were strongly positive in urease activity in vitro; Streptococcus mitior, Staphylococcus intermedius, Micrococcus kristinae, Selenomonas ruminantum, Bacteroides ureolyticus and Lactobacillus casei ss. pseudoplantarum from the healthy volunteers. These results imply the homeostatic regulation system of faecal ammonia concentration by urease-producing microorganisms in the patient.

Patterns of Susceptibility to Fluoroquinolones Among Anaerobic Bacterial Isolates in the United States

The activity of the fluoroquinolone antibiotics against anaerobic bacteria has generally been moderate to poor. Nalidixic acid and cinoxacin show poor activity against almost all anaerobes. Norfloxacin and enoxacin exhibit poor anaerobic activity (MIC90, 8- > 256 micrograms/mL) except against Clostridium perfringens, Bacteroides ureolyticus, and some eubacteria. Norfloxacin is slightly more active than enoxacin against some Bacteroides species. While ciprofloxacin is more active than earlier fluoroquinolones against anaerobes such as Bacteroides fragilis (MIC90, 4-16 micrograms/mL), fusobacteria, and peptostreptococci, its activity is often variable and its MIC90 is frequently close to the maximal level attainable in serum. Ofloxacin is active against B. fragilis (MIC90, 4-8 micrograms/mL) but not against other species of the B. fragilis group (MIC90, 8-32 micrograms/mL); other anaerobes (e.g., peptostreptococci and fusobacteria) are generally susceptible to < or = 8 micrograms of ofloxacin/mL. Several newer quinolones exhibit improved anaerobic activity (although the studies yielding relevant data have often used diverse methods, small numbers and varieties of isolates, and different breakpoints). CI-960 and WIN 57273 inhibit 95% of strains tested at < or = 2 micrograms/mL. CI-990, sparfloxacin, and temafloxacin inhibit most anaerobes at < or = 2 micrograms/mL, but clustering around the breakpoint and strain variability have been noted. CI-990 is active against more than 85% of B. fragilis strains (MIC90, 4 micrograms/mL), but other species of the B. fragilis group often require > 4 micrograms/mL for inhibition; Prevotella bivia, Fusobacterium varium, and Fusobacterium ulcerans are usually resistant.(ABSTRACT TRUNCATED AT 250 WORDS)

New findings on the microbial flora associated with adult periodontitis

The predominant microbial flora associated with adult periodontitis was investigated in 21 patients aged 20–40 years. Microorganisms from samples of subgingival plaque were cultured on selective and non-selective media under aerobic and anaerobic conditions. Ten species or groups out of a total of 31 were found to comprise the predominant cultivable flora: diphtheroids, Porphyromonas asaccharolytica, coagulase-negative staphylococci, ‘ Streptococcus milleri’-group, Bacteroides ureolyticus, Capnocytophaga ochracea, the Prevotella veroralis/buccalis complex, P. intermedia, P. oralis and unidentified Prevotella spp. Two species previously reported at periodontitis sites, namely P. gingivalis and Fusobacterium nucleatum, were not isolated, whereas Prevotella species accounted for the majority of isolates in this investigation. The large proportions of non-pigmented Prevotella species, P. asaccharolytica and B. ureolyticus that were found have not generally been reported previously. The role of these microorganisms and also coagulase-negative staphylococci, diphtheroids and the ‘ Streptococcus milleri’-group requires further investigation in adult periodontitis.