Pediatric orbital cellulitis: Case report of an unusual etiology and pathogen

Orbital cellulitis is an uncommon condition with risks to sight and life. As a complication of maxillofacial injuries, the literature suggests this is only possible with fractures or direct inoculation, and there are no reports to the contrary. Here, we make the first report of a possible etiology by which orbital cellulitis developed in a 14-year-old boy even without skin breach or bony fractures; as well as a rare causative pathogen. He presented with facial abscess and progressive orbital cellulitis after blunt facial trauma, requiring functional endoscopic sinus surgery with needle aspiration of facial abscess externally. Cultures showed growth of Streptococcus constellatus/Parvimonas micra, and he received further antibiotics with full recovery. The pathophysiology of orbital cellulitis in this patient is attributed to vascular congestion and local pressure from maxillofacial contusion and maxillary hemoantrum, with impaired paranasal sinus ventilation encouraging anaerobic bacterial growth. Further progression led to facial abscess formation and intraorbital spread with orbital cellulitis. The pediatric demographic is injury-prone, and self-reporting of symptoms can be delayed. Hence, increased suspicion of complicated injuries and orbital cellulitis may be required when managing maxillofacial contusions so that prompt treatment can be given.

Colorectal Cancer-Associated Microbiome Patterns and Signatures

The gut microbiome is dynamic and shaped by diet, age, geography, and environment. The disruption of normal gut microbiota (dysbiosis) is closely related to colorectal cancer (CRC) risk and progression. To better identify and characterize CRC-associated dysbiosis, we collected six independent cohorts with matched normal pairs (when available) for comparison and exploration of the microbiota and their interactions with the host. Comparing the microbial community compositions between cancerous and adjacent noncancerous tissues, we found that more microbes were depleted than enriched in tumors. Despite taxonomic variations among cohorts, consistent depletion of normal microbiota (members of Clostridia and Bacteroidia) and significant enrichment of oral-originated pathogens (such as Fusobacterium nucleatum and Parvimonas micra) were observed in CRC compared to normal tissues. Sets of hub and hub-connecting microbes were subsequently identified to infer microbe-microbe interaction networks in CRC. Furthermore, biclustering was used for identifying coherent patterns between patients and microbes. Two patient-microbe interaction patterns, named P0 and P1, can be consistently identified among the investigated six CRC cohorts. Characterization of the microbial community composition of the two patterns revealed that patients in P0 and P1 differed significantly in microbial alpha and beta diversity, and CRC‐associated microbiota changes consist of continuous populations of widespread taxa rather than discrete enterotypes. In contrast to the P0, the patients in P1 have reduced microbial alpha diversity compared to the adjacent normal tissues, and P1 possesses more oral-related pathogens than P0 and controls. Collectively, our study investigated the CRC-associated microbiome changes, and identified reproducible microbial signatures across multiple independent cohorts. More importantly, we revealed that the CRC heterogeneity can be partially attributed to the variety and compositional differences of microbes and their interactions to humans.

Parvimonas parva sp. nov., derived from a human genito-urinary lesion

A strain of obligately anaerobically growing Gram-positive cocci was isolated from a human genito-urinary sample and characterized by a polyphasic approach. Analyses of 16S rRNA gene and whole-genome sequences of this strain S3374T indicated that it belonged to the genus Parvimonas . Overall genome relatedness index calculations confirmed it to be phylogenetically distinct from Parvimonas micra (NCTC 11808T) as its most closely related species with standing in nomenclature, with average nucleotide identity and genome-to-genome distance values of 85.8 and 30.2 %, respectively. Biochemically, strain S3374T was strongly proteolytic and can be differentiated from P. micra (DSM 20468T) by absence of phosphatase activity. The DNA G+C content of strain S3374T was 28.6 mol%. Based on the phenotypical, biochemical and genetic findings, strain S3374T is considered to represent a novel species within the genus Parvimonas , for which the name Parvimonas parva sp. nov. is proposed. The type strain is S3374T (=DSM 110786T=CCOS 1934T=CCUG 74294T). This description adds strain S3374T as a second species to the genus Parvimonas which has so far been monotypic. While the type strain of this genus, P. micra , has a long standing in nomenclature and its role in human health and disease has been studied to some extent, this description of the proposed novel species represented by strain S3374T will allow microbiologists worldwide to identify isolates of P. parva sp. nov., a prerequisite for further investigation of its relevance in the clinical context and beyond.

Blowout fracture-associated orbital cellulitis progressing to panophthalmitis: a case report

Background Parvimonas micra is known as a causative agent of chronic periodontal disease. This Gram-positive obligate anaerobic coccus was cultured from the ocular surface of blowout fracture-related orbital cellulitis progressing to panophthalmitis. Case presentation The patient was a woman in her fifties who had panic disorder and subsequently was a victim of domestic violence. These factors led to delayed consultation. At the initial visit to an ophthalmologist, the ocular surface of the right eye was covered with pus. Swelling of the upper and lower eyelids prevented the eyelid from closing and exophthalmos, severe corneal ulcer, panophthalmitis, and no light perception were observed. Head computed tomography revealed an old blowout fracture and chronic sinusitis with orbital cellulitis. P. micra were isolated from culture of pus samples from the sinus and from the ocular surface. Conclusions There is a possibility that P. micra invaded the orbit via the fragile bony site and caused orbital cellulitis, severe corneal ulcer, and panophthalmitis that required enucleation. In cases of coexisting old blowout fracture and chronic sinusitis, the chronic sinusitis should be treated as quickly as possible.

Characterization of the Subgingival Cultivable Microbiota in Patients with Different Stages of Periodontitis in Spain and Colombia. A Cross-Sectional Study

The objective was to characterize and compare the subgingival microbiota in patients diagnosed according to the World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions 2018. For this cross-sectional study, Spanish and Colombian subjects (characterized as health/gingivitis, periodontitis in stages I-II or stages III-IV) were clinically assessed, and subgingival samples were taken and processed by culture. The comparisons among patients with periodontal status (and between countries) was made using Mann–Whitney, Kruskal–Wallis, ANOVA and chi-square tests. The final sample consisted of 167 subjects. Eikenella corrodens and Parvimonas micra were more frequently detected in health/gingivitis and Porphyromonas gingivalis in periodontitis (p < 0.05). Higher total counts were observed in Colombia (p = 0.036). In Spain, significantly higher levels of P. gingivalis and Campylobacter rectus were observed, and of Tannerella forsythia, P. micra, Prevotella intermedia, Fusobacterium nucleatum, Actinomyces odontolyticus and Capnocytophaga spp. in Colombia (p < 0.001). P. micra was more prevalent in health/gingivitis and stage I-II periodontitis in Colombia, and P. gingivalis in all periodontitis groups in Spain (p < 0.05). As conclusions, significant differences were detected in the microbiota between health/gingivitis and periodontitis, with minor differences between stages of periodontitis. Differences were also relevant between countries, with Colombia showing larger counts and variability of bacterial species.

In Vitro Antimicrobial Susceptibility Profiles of Gram-Positive Anaerobic Cocci Responsible for Human Invasive Infections

The aim of this multicentre study was to determine the in vitro susceptibility to anti-anaerobic antibiotics of Gram-positive anaerobic cocci (GPAC) isolates responsible for invasive infections in humans. A total of 133 GPAC isolates were collected in nine French hospitals from 2016 to 2020. All strains were identified to the species level (MALDI-TOF mass spectrometry, 16S rRNA sequencing). Minimum inhibitory concentrations (MICs) of amoxicillin, piperacillin, cefotaxime, imipenem, clindamycin, vancomycin, linezolid, moxifloxacin, rifampicin, and metronidazole were determined by the reference agar dilution method. Main erm-like genes were detected by PCR. The 133 GPAC isolates were identified as follows: 10 Anaerococcus spp., 49 Finegoldia magna, 33 Parvimonas micra, 30 Peptoniphilus spp., and 11 Peptostreptococcus anaerobius. All isolates were susceptible to imipenem, vancomycin (except 3 P. micra), linezolid and metronidazole. All isolates were susceptible to amoxicillin and piperacillin, except for P. anaerobius (54% and 45% susceptibility only, respectively). MICs of cefotaxime widely varied while activity of rifampicin, and moxifloxacin was also variable. Concerning clindamycin, 31 were categorized as resistant (22 erm(A) subclass erm(TR), 7 erm(B), 1 both genes and 1 negative for tested erm genes) with MICs from 8 to >32 mg/L. Although GPACs are usually susceptible to drugs commonly used for the treatment of anaerobic infections, antimicrobial susceptibility should be evaluated in vitro.

ANALYSIS OF MICROBLE LANDSCAPE IN CHILDREN WITH DISEASES

Выявляемость патогенных и условно- патогенных микроорганизмов было в два раза выше в основной группе (24 изолята), чем в контрольной- 12 изолят. Немаловажное значение имеет, что у детей с гастродуоденальной патологией отмечается симбиоз патогенных анаэробных микроорганизмов: Escherichia coli5,5%, Enterobacter cloacae2,7%, Enterobacter aerogenes2,7%, Pantoea agglomerans2,7%, Pseudomonas putida2,7%, Veillonella spp. 2,7%, Parvimonas micra 2,7%, Actinomyces naeslundii2,7%, Actinomyces meyeri2,7%, Clostridium histolyticum2,7% , которые усугубляют течение заболевания. При этом сравнительная характеристика показало, анаэробных штаммов высеяно в основной группе в 84,6% случаях по сравнению с контрольной - 15,4%. The detectability of pathogenic and opportunistic microorganisms was twice as high in the main group (24 isolates) than in the control group (12 isolates). It is also important that children with gastroduodenal pathology have a symbiosis of pathogenic anaerobic microorganisms: Escherichia coli 5.5%, Enterobacter cloacae 2.7%, Enterobacter aerogenes 2.7%, Pantoea agglomerans 2.7%, Veudomonas putidaon 2.7%. 2.7%, Parvimonas micra 2.7%, Actinomyces naeslundii 2.7%, Actinomyces meyeri 2.7%, Clostridium histolyticum 2.7%, which aggravate the course of the disease. At the same time, the comparative characteristics showed that anaerobic strains were sown in the main group in 84.6% of cases compared to the control group - 15.4%.