In Vitro Evaluation of the Activity of Aztreonam-Avibactam against 341 Recent Clinical Isolates of Anaerobes.

Aztreonam-avibactam is under clinical development for multidrug-resistant Gram-negative infections. We evaluated in vitro activity against 341 recent clinical isolates. The addition of avibactam to aztreonam had no effect on the anaerobic activity of aztreonam. IMPORTANCE This work shows that aztreonam-avibactam lacks activity against anaerobic organisms.

A 45-Year-Old Man With Acute Chest Pain, Fever, and Dyspnea After Tooth Extraction.

CASE PRESENTATION: A 45-year-old Japanese man underwent wisdom tooth extraction. He developed right chest pain 2 days later, followed by continuous fever with dyspnea 2 weeks after the tooth extraction, and then came to our hospital. He complained of cough and purulent sputum.

Etiology and antimicrobial susceptibility profiles of anaerobic bacteria isolated from clinical samples in a university hospital in Madrid, Spain.

BACKGROUND: The anaerobic infection management is usually based on empirical treatment because anaerobic culture techniques take a long time due to their fastidious nature. The aim of this study was to analyze the etiological profile of severe anaerobic infections and AST data from clinical anaerobic bacteria isolated in a tertiary hospital in Madrid (Spain). MATERIAL AND METHODS: A consecutive study was carried out over 19 months in Ramón y Cajal Universitary Hospital, Madrid. Clinical samples were processed in appropriate anaerobic media and incubated using Anoxomat system. Identification was performed by MALDI-TOF. AST were determined with gradient diffusion method using EUCAST (penicillin, co-amoxiclav, imipenem, clindamycine and metronidazole) or CLSI (cefoxitin) breakpoints. RESULTS: During the period of study, 503 anaerobic microorganisms isolated from 424 clinical samples were included. Twenty-six percent of the cultures were monomicrobial, while 70.0% also contained aerobic bacteria. The most common source of infection was abscesses (26%), while blood infections represented the 11%. Anaerobic gram-negative bacilli were predominant (41%), being Bacteroides fragilis (13%) the most prevalent overall; anaerobic gram-positive bacilli represented 35%, anaerobic gram-positive cocci 19% and anaerobic gram-negative cocci 5%. Metronidazole and imipenem were the most effective agents tested against anaerobic bacteria, while clindamycin presented higher resistance rates. CONCLUSION: Antimicrobial susceptibility surveillance of anaerobic bacteria should be performed to monitor changes in resistance patterns and to be able to optimize empiric antimicrobial treatment. Reliable species identification and quick reporting of results would guide clinicians to select the optimal antimicrobial therapy.

Exploration of microbial communities contributing to effective methane production from scum under anaerobic digestion.

Scum is formed by the adsorption of long-chain fatty acids (LCFAs) onto biomass surface in anaerobic digestion of oily substrates. Since scum is a recalcitrant substrate to be digested, it is disposed via landfilling or incineration, which results in biomass washout and a decrease in methane yield. The microbes contributing to scum degradation are unclear. This study aimed to investigate the cardinal microorganisms in anaerobic scum digestion. We pre-incubated a sludge with scum to enrich scum-degrading microbes. Using this sludge, a 1.3-times higher methane conversion rate (73%) and a faster LCFA degradation compared with control sludge were attained. Then, we analyzed the cardinal scum-degrading microbes in this pre-incubated sludge by changing the initial scum-loading rates. Increased 16S rRNA copy numbers for the syntrophic fatty-acid degrader Syntrophomonas and hydrogenotrophic methanogens were observed in scum high-loaded samples. 16S rRNA amplicon sequencing indicated that Syntrophomonas was the most abundant genus in all the samples. The amino-acid degrader Aminobacterium and hydrolytic genera such as Defluviitoga and Sporanaerobacter became more dominant as the scum-loading rate increased. Moreover, phylogenic analysis on Syntrophomonas revealed that Syntrophomonas palmitatica, which is capable of degrading LCFAs, related species became more dominant as the scum-loading rate increased. These results indicate that a variety of microorganisms that degrade LCFAs, proteins, and sugars are involved in effective scum degradation.

Clinical and microbiological features of anaerobic implant-related infection in 80 patients after orthopedic surgery.

OBJECTIVES: Implant-related infection is a common complication after orthopedic surgery, but there is limited research focused on anaerobic infections. We retrospectively analyzed data from 80 patients with anaerobic implant-related infections in order to investigate the clinical features, bacterial distribution and antimicrobial resistant characteristics of this disease. METHODS: 80 patients who underwent implant-related infections with anaerobes were included. Pathogens were isolated and identified by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry with verification of 16s rRNA sequencing. Antimicrobial susceptibility testing (AST) was performed using Epsilometric test (E-test). RESULTS: Among the 80 patients, 61.2% (49/80) were infected with anaerobes alone, while 38.8% (31/80) were co-infected with anaerobes and other bacteria. Early infection cases involving anaerobe-alone infections were significantly higher compared to the co-infection group (P < 0.001), also exhibiting lower levels of neutrophils (P = 0.033) and ESR (P = 0.046). Anaerobe-alone infections in the prosthetic joint infection group represented a higher proportion compared with other implant-related infections (P = 0.031). Among all species of anaerobes identified, the top 3 were Cutibacterium acnes, Finegoldia magna and Peptostreptococcus anaerobius. Low MIC values to vancomycin was recorded in C. acnes strains and for amoxicillin/clavulanic acid and piperacillin/tazobactam in most F. magna strains. One of the C. acnes and F. magna strains appeared multi-drug resistant except to vancomycin. CONCLUSIONS: Anaerobe-alone infections have later first onset times and lower infection biomarker levels compared to co-infected patients. The first choice against C. acnes is vancomycin, while amoxicillin/clavulanic acid and piperacillin/tazobactam are recommended for F. magna.

Engraftment of strictly anaerobic oxygen-sensitive bacteria in irritable bowel syndrome patients following fecal microbiota transplantation does not improve symptoms.

Dysbiosis of the gut microbiome has been correlated with irritable bowel syndrome (IBS). Fecal microbiota transplantation (FMT) is being explored as a therapeutic option. Little is known of the mechanisms of engraftment of microbes following FMT and whether the engraftment of certain microbes correlate with clinical improvement in IBS. Microbiome data, from a previously reported placebo-controlled trial of treatment of IBS with FMT or placebo capsules, were used to investigate microbial engraftment 15 days, 1, 3 and 6 months after treatment through assessment of gains, losses and changes in abundance of amplicon sequence variants (ASVs) and microbial diversity (CHAO-1 richness) between the FMT group and the placebo group. These data were compared to changes in IBS Symptom Severity Scores (IBS-SSS). Twelve days of treatment with 25 daily multi-donor FMT capsules induced significant short- and long-term changes in the recipients' microbiomes for at least 6 months, with persistent engraftment of a variety of anaerobic bacteria from keystone genera, such as Faecalibacterium, Prevotella and Bacteroides and increased microbial diversity, particularly in patients with low initial diversity. FMT recipients lost ASVs after treatment, which was seen to a much lesser extent in the placebo group. No ASVs increased to a greater extent between FMT responders and non-responders following treatment. Major long-term changes, lasting for at least 6 months, in the gut microbiomes of IBS patients are seen following treatment with FMT capsules. None of these changes correlated with clinical improvement. The relationship between the microbiome and the etiology of IBS still remains unsolved.

The Urinary Microbiome in Postmenopausal Women with Recurrent Urinary Tract Infections.

PURPOSE: The etiology of postmenopausal recurrent urinary tract infection (UTI) is not completely known, but the urinary microbiome is thought to be implicated. We compared the urinary microbiome in menopausal women with recurrent UTIs to age-matched controls, both in the absence of acute infection. MATERIALS AND METHODS: This is a cross-sectional analysis of baseline data from 64 women enrolled in a longitudinal cohort study. All women were using topically applied vaginal estrogen. Women >55 years of age from the following groups were enrolled: 1) recurrent UTIs on daily antibiotic prophylaxis, 2) recurrent UTIs not on antibiotic prophylaxis and 3) age-matched controls without recurrent UTIs. Catheterized urine samples were collected at least 4 weeks after last treatment for UTI and at least 6 weeks after initiation of vaginal estrogen. Samples were evaluated using expanded quantitative urine culture (EQUC) and 16S rRNA gene sequencing. RESULTS: With EQUC, there were no significant differences in median numbers of microbial species isolated among groups (p=0.96), even when considering Lactobacilli (p=0.72). However, there were trends toward different Lactobacillus species between groups. With 16S rRNA sequencing, the majority of urine samples contained Lactobacillaceae, with nonsignificant trends in relative abundance among groups. Using a Bayesian analysis, we identified significant differences in anaerobic taxa associated with phenotypic groups. Most of these differences centered on Bacteroidales and the family Prevotellaceae, although differences were also noted in Actinobacteria and certain genera of Clostridiales. CONCLUSIONS: Associations between anaerobes within the urinary microbiome and postmenopausal recurrent UTI warrants further investigation.

Peptoniphilus faecalis sp. nov., isolated from swine faeces.

An obligately anaerobic, Gram-positive, non-motile, coccus-shaped bacterial strain designated AGMB00490T was isolated from swine faeces. 16S rRNA gene sequence-based phylogenetic analysis indicated that the isolate belongs to the genus Peptoniphilus and that the most closely related species is Peptoniphilus gorbachii WAL 10418T (=KCTC 5947T, 97.22 % 16S rRNA gene sequence similarity). Whole genome sequence analysis determined that the DNA G+C content of strain AGMB00490T was 31.2 mol% and moreover that the genome size and numbers of tRNA and rRNA genes were 2 129 517 bp, 34 and 10, respectively. Strain AGMB00490T was negative for oxidase and urease; positive for catalase, indole production, arginine arylamidase, leucine arylamidase, tyrosine arylamidase and histidine arylamidase; and weakly positive for phenylalanine arylamidase and glycine arylamidase. The major cellular fatty acids (>10 %) of the isolate were determined to be C16 : 0 and C18 : 1 ω9c. Strain AGMB00490T produced acetic acid as a major end product of metabolism. Accordingly, phylogenetic, physiologic and chemotaxonomic analyses revealed that strain AGMB00490T represents a novel species for which the name Peptoniphilus faecalis sp. nov. is proposed. The type strain is AGMB00490T (=KCTC 15944T=NBRC 114159T).

Antimicrobial susceptibility profiles of invasive isolates of anaerobic bacteria from a large Canadian reference laboratory: 2012-2019.

Anaerobic bacteria can cause severe and life threatening infections. Susceptibility data are relatively limited on anaerobic organisms despite the clinical importance in guiding empiric treatment of infections. To determine antimicrobial susceptibility profiles of clinically significant anaerobic bacteria, isolates obtained from sterile sites submitted to Public Health Ontario Laboratory (2012-2019) were included in this study (N = 5712). Cefoxitin, clindamycin, metronidazole, meropenem, penicillin and piperacillin-tazobactam were tested using the gradient strip method with MICs interpreted based on Clinical and Laboratory Standards Institute guidelines. Bacteroides spp. (N = 958; 16.7%), Clostridium spp. (N = 798; 14.0%), Cutibacterium spp. (N =659; 11.5%) and Actinomyces spp. (N = 551; 7.0%) were the most commonly isolated genera. Bacteroides fragilis isolates were susceptible to cefoxitin (88.4%), clindamycin (68.4%), metronidazole (96.0%), meropenem (99.0%) and piperacillin-tazobactam (98.4%). Other Bacteroides spp. showed reduced susceptibility to several antimicrobials. Clostridium spp. isolates were susceptible to penicillin (69.7%), clindamycin (69.7%) and cefoxitin (76.3%); C. perfringens and C. ramosum showed distinct susceptibility profiles. Susceptibility rates among anaerobes remained relatively unchanged over 8 years with a few exceptions: C. perfringens susceptibility to clindamycin decreased from 91.3% to 60% (p = 0.03); Clostridium spp. susceptibility to penicillin similarly decreased from 82.1% to 65.9% (p = 0.03); Eggerthella spp. susceptibility to piperacillin-tazobactam decreased from 100% to 24.3% (p < 0.001); B. fragilis group susceptibility to cefoxitin decreased from 70.4% to 48.2% (p = 0.05); and Parabacteroides spp. susceptibility to piperacillin-tazobactam decreased from 100% to 25% (p = 0.01). Our findings underscore the need for ongoing surveillance and periodic monitoring of antimicrobial resistance in order to guide empiric therapy.

Alkalicella caledoniensis gen. nov., sp. nov., a novel alkaliphilic anaerobic bacterium isolated from 'La Crouen' alkaline thermal spring, New Caledonia.

A novel anaerobic, alkaliphilic, mesophilic, Gram-stain-positive, endospore-forming bacterium was isolated from an alkaline thermal spring (42 °C, pH 9.0) in New Caledonia. This bacterium, designated strain LB2T, grew at 25-50 °C (optimum, 37 °C) and pH 8.2-10.8 (optimum, pH 9.5). Added NaCl was not required for growth (optimum, 0-1 %) but was tolerated up to 7 %. Strain LB2T utilized a limited range of substrates, such as peptone, pyruvate, yeast extract and xylose. End products detected from pyruvate fermentation were acetate and formate. Both ferric citrate and thiosulfate were used as electron acceptors. Elemental sulphur, nitrate, nitrite, fumarate, sulphate, sulfite and DMSO were not used as terminal electron acceptors. The two major cellular fatty acids were iso-C15 : 0 and C16 : 0. The genome consists of a circular chromosome (3.7 Mb) containing 3626 predicted protein-encoding genes with a G+C content of 36.2 mol%. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the isolate is a member of the family Proteinivoraceae, order Clostridiales within the phylum Firmicutes. Strain LB2T was most closely related to the thermophilic Anaerobranca gottschalkii LBS3T (93.2 % 16S rRNA gene sequence identity). Genome-based analysis of average nucleotide identity and digital DNA-DNA hybridization of strain LB2T with A. gottschalkii LBS3T showed respective values of 70.8 and 13.4 %. Based on phylogenetic, genomic, chemotaxonomic and physiological properties, strain LB2T is proposed to represent the first species of a novel genus, for which the name Alkalicella caledoniensis gen. nov., sp. nov. is proposed (type strain LB2T=DSM 100588T=JCM 30958T).

Three is a crowd: Clinical outcomes of a twice daily versus a thrice daily metronidazole dosing strategy from a multicenter study.

This was a multicenter, retrospective study of patients with anaerobic bacteremia comparing metronidazole 500 mg every 8 h versus 500 mg every 12 h. Of 782 patients reviewed, 85 met inclusion criteria. There was no significant difference in mortality, length of stay, or escalation of therapy between dosing strategies.

Illumina sequencing of 16S rRNA genes reveals a unique microbial community in three anaerobic sludge digesters of Dubai.

Understanding the microbial communities in anaerobic digesters, especially bacteria and archaea, is key to its better operation and regulation. Microbial communities in the anaerobic digesters of the Gulf region where climatic conditions and other factors may impact the incoming feed are not documented. Therefore, Archaeal and Bacterial communities of three full-scale anaerobic digesters, namely AD1, AD3, and AD5 of the Jebel Ali Sewage water Treatment Plant (JASTP) were analyzed by Illumina sequencing of 16S rRNA genes. Among bacteria, the most abundant genus was fermentative bacteria Acetobacteroides (Blvii28). Other predominant bacterial genera in the digesters included thermophilic bacteria (Fervidobacterium and Coprothermobacter) and halophilic bacteria like Haloterrigena and Sediminibacter. This can be correlated with the climatic condition in Dubai, where the bacteria in the incoming feed may be thermophilic or halophilic as much of the water used in the country is desalinated seawater. The predominant Archaea include mainly the members of the phyla Euryarchaeota and Crenarchaeota belonging to the genus Methanocorpusculum, Metallosphaera, Methanocella, and Methanococcus. The highest population of Methanocorpusculum (more than 50% of total Archaea), and other hydrogenotrophic archaea, is in agreement with the high population of bacterial genera Acetobacteroides (Blvii28) and Fervidobacterium, capable of fermenting organic substrates into acetate and H2. Coprothermobacter, which is known to improve protein degradation by establishing syntrophy with hydrogenotrophic archaea, is also one of the digesters' dominant genera. The results suggest that the microbial community in three full-scale anaerobic digesters is different. To best of our knowledge this is the first detailed report from the UAE.

Isolation and identification of a human intestinal bacterium capable of daidzein conversion.

Equol, which produced from daidzein (one of the principal isoflavones), is recognized to be the most resultful in stimulating an estrogenic and antioxidant response. The daidzein transformation was studied during fermentation of five growth media inoculated with feces from a healthy human, and a daidzein conversion strain was isolated. To enrich the bacterial population involved in daidzein metabolism in a complex mixture, fecal samples were treated with antibiotics. The improved propidium monoazide combined with the quantitative polymerase chain reaction (PMAxx-qPCR) assay showed that the ampicillin treatment of samples did result in a reduction of the total visible bacteria counts by 52.2% compared to the treatment without antibiotics. On this basis, the newly isolated rod-shaped, Gram-positive anaerobic bacterium, named strain Y11 (MN560033), was able to metabolize daidzein to equol under anaerobic conditions, with a conversion ratio (equol ratio: the amount of equol produced/amount of supplemented daizein) of 0.56 over 120 h. The 16S rRNA partial sequence of the strain Y11 exhibited 99.8% identity to that of Slackia equolifaciens strain DZE (NR116295). This study will provide new insights into the biotransformation of equol from daidzein by intestinal microbiota from the strain-level and explore the possibility of probiotic interventions.

An observational study of anaerobic bacteria in cystic fibrosis lung using culture dependant and independent approaches.

Strict anaerobes are undeniably important residents of the cystic fibrosis (CF) lung but are still unknowns. The main objectives of this study were to describe anaerobic bacteria diversity in CF airway microbiota and to evaluate the association with lung function. An observational study was conducted during eight months. A hundred and one patients were enrolled in the study, and 150 sputum samples were collected using a sterile sample kit designed to preserve anaerobic conditions. An extended-culture approach on 112 sputa and a molecular approach (quantitative PCR targeting three of the main anaerobic genera in CF lung: Prevotella, Veillonella, and Fusobacterium) on 141 sputa were developed. On culture, 91.1% of sputa were positive for at least one anaerobic bacterial species, with an average of six anaerobic species detected per sputum. Thirty-one anaerobic genera and 69 species were found, which is the largest anaerobe diversity ever reported in CF lungs. Better lung function (defined as Forced Expiratory Volume in one second > 70%) was significantly associated with higher quantification of Veillonella. These results raise the question of the potential impact of anaerobes on lung function.

Antimicrobial susceptibility testing of Eggerthella lenta blood culture isolates at a university hospital in Belgium from 2004 to 2018.

OBJECTIVES: Eggerthella lenta is a Gram-positive anaerobic bacillus that is an important cause of bloodstream infections. This study aims to test the susceptibility of Eggerthella lenta blood culture isolates to commonly used antibiotics for the empirical treatment of anaerobic infections. METHODS: In total, 49 positive blood cultures for Eggerthella lenta were retrospectively included from patients hospitalised at the Universitair Ziekenhuis Brussel, Belgium, between 2004 and 2018. Identification was done by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system. Antimicrobial susceptibility testing was performed using the reference agar dilution method according to Clinical and Laboratory Standards Institute (CLSI) guidelines with Brucella agar supplemented with 5 µg/mL hemin, 1 µg/mL vitamin K1 and 5% laked sheep blood. The minimal inhibitory concentrations were interpreted using the EUCAST breakpoints. Clinical characteristics were collected by reviewing the patient's medical records. RESULTS: All isolates were susceptible to amoxicillin-clavulanate, metronidazole and meropenem. Eighty-eight % of them were susceptible to clindamycin and 94% (20% S, 74% I) were susceptible to piperacillin-tazobactam. The mean age of the patients was 64 (±20) and they showed a 30-day mortality of 27%. The source of infection was in 65.3% of the cases abdominal, 20.4% were sacral pressure ulcers and 14.3% were unknown causes. While all isolates were fully susceptible at standard dosing regimen to amoxicillin-clavulanate, most were only susceptible at increased exposure or resistant to piperacillin-tazobactam. CONCLUSIONS: Our results suggest to be careful with the use of piperacillin-tazobactam and clindamycin in the empirical treatment of Eggerthella lenta infections.

Comparison of Strategies for Isolating Anaerobic Bacteria from the Porcine Intestine.

The isolation of bacteria that represent the diversity of autochthonous taxa in the gastrointestinal tract is necessary to fully ascertain their function, but the majority of bacterial species inhabiting the intestines of mammals are fastidious and thus challenging to isolate. The goal of the current study was to isolate a diverse assemblage of anaerobic bacteria from the intestine of pigs as a model animal and to comparatively examine various novel and traditional isolation strategies. Methods used included long-term enrichments, direct plating, a modified ichip method, as well as ethanol and tyndallization treatments of samples to select for endospore-forming taxa. A total of 234 taxa (91 previously uncultured) comprising 80 genera and 7 phyla were isolated from mucosal and luminal samples from the ileum, cecum, ascending colon, and spiral colon removed from animals under anesthesia. The diversity of bacteria isolated from the large intestine was less than that detected by next-generation sequence analysis. Long-term enrichments yielded the greatest diversity of recovered bacteria (Shannon's index [SI] = 4.7). Methods designed to isolate endospore-forming bacteria produced the lowest diversity (SI ≤ 2.7), with tyndallization yielding lower diversity than the ethanol method. However, the isolation frequency of previously uncultured bacteria was highest for ethanol-treated samples (41.9%) and the ichip method (32.5%). The goal of recovering a diverse collection of enteric bacteria was achieved. Importantly, the study findings demonstrate that it is necessary to use a combination of methods in concert to isolate bacteria that are representative of the diversity within the intestines of mammals.IMPORTANCE This work determined that using a combination of anaerobic isolation methods is necessary to increase the diversity of bacteria recovered from the intestines of monogastric mammals. Direct plating methods have traditionally been used to isolate enteric bacteria, and recent methods (e.g., diffusion methods [i.e., ichip] or differential isolation of endospore-forming bacteria) have been suggested to be superior at increasing diversity, including the recovery of previously uncultured taxa. We showed that long-term enrichment of samples using a variety of media isolated the most diverse and novel bacteria. Application of the ichip method delivered a diversity of bacteria similar to those of enrichment and direct plating methods. Methods that selected for endospore-forming bacteria generated collections that differed in composition from those of other methods with reduced diversity. However, the ethanol treatment frequently isolated novel bacteria. By using a combination of methods in concert, a diverse collection of enteric bacteria was generated for ancillary experimentation.

Detection of associated bacteria in aspiration pneumonia and lung abscesses using partial 16S rRNA gene amplicon sequencing.

OBJECTIVES: Lower respiratory tract infections (LRTIs) are often caused by the patient's own oral commensal bacteria. Causative bacteria must be identified to select the appropriate antimicrobial agents; however, the pathogens are identified via routine culture methods in only approximately half of LRTI cases. METHODS: To investigate LRTI-associated bacteria, we conducted culture testing under aerobic and anaerobic conditions using culture-independent partial 16S rRNA gene amplicon sequencing analysis using a high-throughput sequencer in cases of aspiration pneumonia and lung abscesses. RESULTS: Culture testing of 17 aspiration pneumonia cases revealed Streptococcus spp. (n = 13), Prevotella spp. (n = 9), and Veillonella spp. (n = 8); 16S rRNA analysis of these cases yielded Streptococcus spp. (n = 16), Veillonella spp. (n = 12), Haemophilus spp. (n = 12), Prevotella spp. (n = 11), and Rothia spp. (n = 11). Culture testing of 8 lung abscess cases revealed Streptococcus spp. (n = 7) and Fusobacterium spp. (n = 4); 16S rRNA analysis of these cases yielded Fusobacterium spp. (n = 8), Prevotella spp. (n = 7), Streptococcus spp. (n = 6), and Porphyromonas spp. (n = 5). All taxa with abundance ratios of ≥50% on the 16S rRNA analysis were also detected in the cultures. However, several taxa were either undetected in the cultures despite relatively high abundance ratios on the 16S rRNA analysis or negative on the 16S rRNA analysis and isolated only by culturing. CONCLUSION: Our data provide a comprehensive list of bacterial taxa that may be associated with aspiration pneumonia and lung abscesses. In empirically treating LRTIs, this information will help determine the best treatment against the targeted anaerobes.

Effect of a Nonoptimal Cervicovaginal Microbiota and Psychosocial Stress on Recurrent Spontaneous Preterm Birth.

OBJECTIVE: While select cervicovaginal microbiota and psychosocial factors have been associated with spontaneous preterm birth, their effect on the risk of recurrence remains unclear. It is also unknown whether psychosocial factors amplify underlying biologic risk. This study sought to determine the effect of nonoptimal cervicovaginal microbiota and perceived stress on the risk of recurrent spontaneous preterm birth. STUDY DESIGN: This was a secondary analysis of a prospective pregnancy cohort, Motherhood and Microbiome. The Cohen's Perceived Stress Scale (PSS-14) was administered and cervical swabs were obtained between 16 and 20 weeks of gestation. PSS-14 scores ≥30 reflected high perceived stress. We analyzed cervicovaginal microbiota using 16S rRNA sequencing and classified microbial communities into community state types (CSTs). CST IV is a nonoptimal cervicovaginal microbial community characterized by anaerobes and a lack of Lactobacillus. The final cohort included a predominantly non-Hispanic Black population of women with prior spontaneous preterm birth who had recurrent spontaneous preterm birth or term birth and had stress measurements (n = 181). A subanalysis was performed in the subset of these women with cervicovaginal microbiota data (n = 74). Multivariable logistic regression modeled adjusted associations between CST IV and recurrent spontaneous preterm birth, high stress and recurrent spontaneous preterm birth, as well as high stress and CST IV. RESULTS: Among the 181 women with prior spontaneous preterm birth, 45 (24.9%) had high perceived stress. We did not detect a significant association between high stress and recurrent spontaneous preterm birth (adjusted odds ratio [aOR] 1.67, 95% confidence interval [CI]: 0.73-3.85). Among the 74 women with prior spontaneous preterm birth and cervicovaginal microbiota analyzed, 29 (39.2%) had CST IV; this proportion differed significantly among women with recurrent spontaneous preterm birth (51.4%) compared with women with term birth (28.2%) (p = 0.04). In models adjusted for race and marital status, the association between CST IV and recurrent spontaneous preterm birth persisted (aOR 3.58, 95% CI: 1.25-10.24). There was no significant interaction between stress and CST IV on the odds of spontaneous preterm birth (p = 0.328). When both stress and CST IV were introduced into the model, their associations with recurrent spontaneous preterm birth were slightly stronger than when they were in the model alone. The aOR for stress with recurrent spontaneous preterm birth was 2.02 (95% CI: 0.61-6.71) and for CST IV the aOR was 3.83 (95% CI: 1.30-11.33). Compared to women with neither of the two exposures, women with both high stress and CST IV had the highest odds of recurrent spontaneous preterm birth (aOR = 6.01, 95% CI: 1.002-36.03). CONCLUSION: Among a predominantly non-Hispanic Black cohort of women with a prior spontaneous preterm birth, a nonoptimal cervicovaginal microbiota is associated with increased odds of recurrent spontaneous preterm birth. Adjustment for perceived stress may amplify associations between CST IV and recurrent spontaneous preterm birth. Identification of modifiable social or behavioral factors may unveil novel nonpharmacologic interventions to decrease recurrent spontaneous preterm birth among women with underlying biologic risk. KEY POINTS: · CST IV, a nonoptimal microbiota, is associated with increased odds of recurrent spontaneous preterm birth.. · Adjustment for perceived stress amplified associations between CST IV and recurrent spontaneous preterm birth.. · Identification of modifiable psychosocial factors may unveil novel nonpharmacologic interventions to decrease recurrent preterm birth..

Anaerobic bacterial communities associated with oral carcinoma: Intratumoral, surface-biofilm and salivary microbiota.

It was estimated that more than 700 bacterial species inhabit the oral cavity of healthy humans. Anaerobes comprise a significant fraction of the oral bacteriome and play an important role in the formation of multi-species biofilms attached to various anatomical sites. Bacterial biofilms are also associated with pathologic laesions of the oral cavity, including oral squamous cell carcinoma (OSCC), and distinct oral taxa could also be detected within the tumors, i.e. in deep biopsy samples. These observations suggested that certain oral bacteria or oral bacterial communities may play a causative role in oral carcinogenesis, in addition to the well characterized risk factors of oral cancer. Alternatively, it was also proposed that a subset of oral bacteria may have a growth advantage in the unique microenvironment of OSCC. Recently, a series of studies analysed the OSCC-associated bacterial communities using metataxonomic, metagenomic and metatranscriptomic approaches. This review outlines the major differences between the community structure of microbiota in tumor biopsy, surface-biofilm and salivary or oral wash samples collected from OSCC patients, compared to corresponding samples from control persons. A special emphasis is given to the anaerobic bacteria Fusobacterium nucleatum and Fusobacterium periodonticum that were characterised repeatedly as "OSCC-associated" in independent studies. Predicted microbial functions and relevant in vivo experimental models of oral carcinogenesis will also be summarized.

[Progress in the treatment of intra-abdominal anaerobic infection].

Most abdominal infections are mixed infections caused by aerobic and anaerobic bacteria. Anaerobic infections are characterized by rancid secretions or abscess formation. Early implementation of source control is the key in the treatment of abdominal anaerobic infections. Damage control should be followed as one of the principles of surgical treatment. As the in vitro isolation and culture of anaerobic bacteria as well as its drug sensitivity test are time-consuming and sometimes inaccurate, the treatment of anaerobic bacteria infection is mostly empirical. Anti-infective therapy should be employed once anaerobic bacteria infection is confirmed. Ertapenem, Mosifloxacin, and Cefoperazone-sulbactam can be used for first-line monotherapy, while combination therapy can use second- or third-generation Cephalosporin, Quinolones plus Nitroimidazoles. Nutritional support and anti-shock treatment should not be neglected when implementing surgical control of infection source and antimicrobial therapy. Considering the increasing drug resistance of anaerobic bacteria, and the higher drug resistance rate in China as compared to western countries, the choice of antibiotics should be made rationally and based on epidemiological characteristics of anaerobic bacteria in different regions.