Pigmented Prevotella Species Research Articles

Evaluation of antibiotic susceptibility of Bacteroides, Prevotella and Fusobacterium species isolated from patients of the N. N. Blokhin Cancer Research Center, Moscow, Russia

In total 122 non-duplicate Bacteroides, Prevotella and Fusobacterium spp isolated from cancer patients between 2004 and 2014 were involved in this study. Most of the strains belonged to the B. fragilis group (55%), followed by Prevotella strains (34.4%) and Fusobacterium spp (10.6%). The species identification was carried out by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and they were identified on species level with a log (score) >2.0. The most common isolates were B. fragilis, B. thetaiotaomicron, B. ovatus and B. vulgatus. Among Prevotella species, the most frequently isolated species were P. buccae, P. buccalis, P. oris, P. denticola and P. nigrescens, and most of the Fusobacterium spp. were F. nucleatum. Susceptibilities of the strains were determined by the E-test methodology. The percentage of the susceptibility of B. fragilis group isolates were: metronidazole (MIC ≤4 μg/ml), 97%; imipenem (MIC ≤2 μg/ml), 95.5%; amoxicillin/clavulanate (MIC ≤4 μg/ml), 95.5% and clindamycin (MIC ≤4 μg/ml), 77.6%. Three B. fragilis isolates proved to be multidrug-resistant (parallel resistance to imipenem, amoxicillin/clavulanate and metronidazole or clindamycin was observed). All Prevotella strains tested were susceptible to imipenem and amoxicillin/clavulanate, whereas 78.6% of the pigmented Prevotella species and 46.4% of the non-pigmented species were resistant to penicillin (MIC >0.5 μg/ml). The susceptibility to metronidazole and clindamycin were 93% and 88%, respectively. All Fusobacterium strains were sensitive to all tested antibiotics, including penicillin.

Recovery of anaerobic bacteria from four children with postthoracotomy sternal wound infection.

The cases of 4 children who developed postthoracotomy sternal wound infection caused by anaerobic bacteria are presented. The predominate anaerobes were Peptostreptococcus species and pigmented Prevotella species. Polymicrobial infection was present in all cases, and aerobic bacteria also were recovered in 2 instances. All patients responded to surgical debridement and antimicrobials effective against the isolated aerobic and anaerobic bacteria. These findings highlight the potential importance of anaerobic bacteria in postthoracotomy sternal wound infection.

Pathogen and resistance spectrum in intraoral infections of the jaw-facial area with special reference to anaerobic bacteria

The aim of the study was to obtain more knowledge about the aerobic and anaerobic species causing maxillofacial infections and their resistance patterns today. Samples of pus or infectious tissue obtained from 110 patients of maxillofacial surgery were investigated microbiologically by means of aerobic and anaerobic cultivation. After incubation, the cultivated species were isolated and identified. The resistance patterns of all bacteria to penicillin, doxycyclin, and clindamycin were determined. Additionally, the resistance of aerobic species to cefuroxim was documented, and the MICs of cefoxitin and metronidazole to the anaerobic species were assessed. The most frequent disease was periodontitis apicalis (70 patients). Aerobic species alone were found in 23% of the samples, 14% of the infections harbored only anaerobes, but 63% were mixed infections caused by aerobic and anaerobic bacteria. In case of detection of aerobic species, streptococci were always identified. Five patients were infected by Staphylococcus aureus and gram-negative aerobic rods were found in eight patients. Most of the anaerobic species were black pigmented prevotella species (62), nonpigmented prevotellae (56), and fusobacteria (37). Metronidazole and clindamycin were highly efficient to gram-negative anaerobic rods. Most of the oral species were resistant to penicillin and doxycyclin. The indication for applying antibiotics should always be noticed and these drugs should only be used after determination of the pathogenic microorganisms and their susceptibility to the antimicrobials.

Recently described clinically important anaerobic bacteria: taxonomic aspects and update.

A new method of identifying bacteria, phylogenetic 16S rRNA sequencing, has led to major reorganizations among most genera of anaerobic bacteria. The pigmented Prevotella species now comprise seven species including P. nigrescens and P. tannerae; P. intermedia/P. nigrescens-like organisms await inclusion. The former Mitsuokella dentalis and Hallella seregens were transferred to Prevotella as one species, P. dentalis. P. enoeca is a new nonpigmenting Prevotella. The genus Porphyromonas currently includes 11 pigmented species and one nonpigmented species, P. catoniae; P. levii-like and P. endodontalis-like organisms are candidates for the genus. Fusobacterium nucleatum currently has five subspecies, and F. varium includes the former F. pseudonecrophorum. Former Wolinella recta and Wolinella curva now are Campylobacter rectus and Campylobacter curvus; Campylobacter showae is a new species. Isolates included in the bile-sensitive former Bacteroides gracilis now are Campylobacter gracilis; the bile-resistant B. gracilis isolates were transferred to a new genus, Sutterella, as S. wadsworthensis. The new Actinomyces species include two subspecies of the A. neuii and the A. radingae-A. turicensis complex. The genus Eubacterium sensu stricto is represented by E. limosum, and the former E. alactolyticum was reclassified in a new genus, Pseudoramibacter, as P. alactolyticus. Recent entries include E. saphenum, E. minutum, E. exiguum, E. infirmum, and E. tardum. A new genus, Atopobium houses some former lactobacilli and streptococci. The genus Peptostreptococcus also have four new species; P. hydrogenalis, P. lacrimalis, P. lactolyticus, and P. vaginalis.

Beta-lactamase production by oral pigmented Prevotella species isolated from young children.

The frequency of beta-lactamase production by oral pigmented Prevotella species isolated from 23 healthy young children and the minimal inhibitory concentrations (MICs) for 186 available beta-lactamase-positive isolates were examined by using the chromogenic cephalosporin disk test (AB BIODISK, Solna, Sweden) and the Etest (AB BIODISK) and/or the agar dilution method of the National Committee for Clinical Laboratory Standards (Villanova, PA, USA), respectively. beta-Lactamase-positive Prevotella melaninogenica strains were isolated from all children, and more than two-thirds of the Prevotella denticola and Prevotella loescheii strains isolated from the children were beta-lactamase-positive. The beta-lactamase-producing Prevotella intermedia group consisted of Prevotella nigrescens and the P. intermedia/ P. nigrescens-like organism (PINLO); P. intermedia was not found. Only two P. nigrescens isolates but most of the PINLO isolates produced beta-lactamase. The MICs for beta-lactamase-producing strains varied between 0.38 and 64 micrograms/mL. beta-Lactamase production by oral pigmented Prevotella species colonizing young children is already frequent. The phenomenon should be taken into account in the treatment of pediatric anaerobic infections of oral origin.

Monthly changes in the rate of recovery of penicillin-resistant organisms from children.

Monthly changes in the rate of recovery of penicillin-resistant organisms from children.

Changes in the core tonsillar bacteriology of recurrent tonsillitis: 1977-1993.

Microbiological studies of the core of tonsils removed from children with recurrent tonsillitis due to group A beta-hemolytic streptococci were conducted during three periods, with 50 patients in each period: 1977-1978 (period 1), 1984-1985 (period 2), and 1992-1993 (period 3). Mixed flora were present in all tonsils, with 8.1 organisms per tonsil (3.8 aerobes and 4.3 anaerobes). The predominant isolates in each period were Staphylococcus aureus, Moraxella catarrhalis, Peptostreptococcus species, pigmented Prevotella species, Porphyromonas species, and Fusobacterium species. The rate of recovery of Haemophilus influenzae type b increased from 24% in period 1 to 76% in period 2 (P < .001); a decline to 12% in period 3 correlated with a concomitant increase in the frequency of recovery of non-type b strains of H. influenzae from 4% and 10% in periods 1 and 2, respectively, to 64% in period 3 (P < .001). Both the rate of recovery of beta-lactamase-producing bacteria and the number of these organisms per tonsil increased over time. Specifically, beta-lactamase-producing strains were detected in 37 tonsils (74%) during period 1, in 46 tonsils (92%) during period 2, and in 47 tonsils (94%) during period 3, and the number of such strains per tonsil increased from 1.1 in period 1 to 2.9 and 3.3 in periods 2 and 3, respectively.

A Retrospective Review of Cases of Anaerobic Empyema and Update of Bacteriology

We conducted a retrospective study to update the bacteriology of 46 cases of anaerobic empyema that were originally studied between 1976 and 1993 at the Wadsworth Anaerobic Bacteriology Clinical Research Laboratory (Los Angeles). Anaerobic bacteriologic studies were completed for all 46 pleural fluid specimens, and aerobic bacteriologic studies were completed for 41 of these specimens. Thirty-seven clinical charts were available for review. A total of 161 anaerobic isolates (3.5 per patient) representing 64 species or groups were recovered. The most common isolates were as follows: Fusobacterium nucleatum (19); Prevotella oris-buccae group (13, 9 of which were P. oris); Bacteroides fragilis group (11, 4 of which were B. fragilis); pigmented Prevotella species (17, 8 of which were in the Prevotella intermedia-nigrescens group); Peptostreptococcus species (17, 9 of which were Peptostreptococcus micros); Eubacterium species (7); Lactobacillus species (8); Actinomyces species (7); and Clostridium species (7). Nineteen if the cases were of purely anaerobic etiology; of these, eight were caused by a single organism: F. nucleatum (five cases); B. fragilis (two cases); and Prevotella mangus (one case). Of the 45 aerobic isolates (1.1 per patient), viridans streptococci were most common (21 isolates), followed by group D nonenterococcal streptococcus (four isolates). Only nine gram-negative rods (six enteric and three nonenteric organisms) and one Staphylococcus aureus isolate were recovered. The susceptibility to penicillin of 64 isolates was examined with the use of the spiral gradient method; 21 (33%) of these isolates were beta-lactamase positive (MICs ranged from 1.1 to > or = 54 micrograms/mL vs < or = 0.27 micrograms/mL for beta-lactamase-negative strains).

Bacteriology of Skin and Soft-Tissue Infections: Comparison of Infections in Intravenous Drug Users and Individuals with No History of Intravenous Drug Use

The bacteriology of cutaneous or subcutaneous abscesses (86 specimens) among intravenous drug users (IVDUs) was compared with the bacteriology of abscesses (74 specimens) in patients with no history of intravenous drug use (non-IVDUs). The IVDU abscesses yielded 173 aerobes and 131 anaerobes. Staphylococcus aureus was the most common aerobe isolated (50% of specimens yielded this isolate), followed by "Streptococcus milleri" (46%). The commonly encountered anaerobes were Fusobacterium nucleatum (17%), pigmented Prevotella species (22%), Peptostreptococcus micros (17%), Actinomyces odontolyticus (15%), and Veillonella species (13%). The non-IVDU isolates included 116 aerobes and 106 anaerobes. S. aureus was isolated from 53% of these specimens, followed by coagulase-negative staphylococci (19%), "S. milleri" (19%), and Streptococcus pyogenes (16%). The main groups of anaerobes were Peptostreptococcus species (35%), Bacteroides species (19%), and gram-positive bacilli (31%). Overall, 67% of the IVDU isolates were of oral origin, compared with 25% of the non-IVDU isolates. Of the specimens from IVDUs and non-IVDUs, 48% and 67%, respectively, yielded only aerobes, and 2% and 4%, respectively, yielded only anaerobes. Sixty-four percent of the patients had one or more beta-lactamase-producing organisms.

Bacteriology of anaerobic pleuropulmonary infections: preliminary report.

A retrospective bacteriologic study of anaerobic pleuropulmonary infections diagnosed at the Wadsworth Veterans Affairs Medical Center between 1976 and 1991 was performed. There were 116 specimens from 110 patients. Available strains were reexamined using the latest tests and taxonomic schemes. Pleural fluid was believed to provide the most reliable specimen; cultures yielded an average of 3.0 anaerobes and 0.6 nonanaerobes per specimen. The most commonly encountered anaerobes were pigmented Prevotella species, nonpigmented Prevotella species, Fusobacterium nucleatum, Peptostreptococcus species, and Bacteroides species. Thirty percent of the anaerobic gram-negative rods were beta-lactamase producers.

Pigmented Prevotella species in the periodontally healthy oral cavity

Pigmented Prevotella species in the periodontally healthy oral cavity