Granulicatella and Abiotrophia species from human clinical specimens

Granulicatella adiacens Bacterial Infection After Pancreatectomy Whipple's Procedure

Background: Granulicatella adiacens inhabits the oral cavity, urogenital, and gastrointestinal tracts and is a typical commensal of human mucosal surfaces. It rarely causes disease. Identification of these gram-positive cocci can be challenging. Case Report: In a 58-year-old male in an oncology center, we report the first occurrence of bacterial infection caused by G. adiacens. After a precise diagnosis of the infection, the patient received effective treatment. Conclusion: Owing to a lack of sufficient diagnostic tools, G. adiacens may be a more notable pathogen than has been previously identified. Sensitivity testing standards are desperately needed.

A shared group of bacterial taxa in the duodenal microbiota of undernourished Pakistani children with environmental enteric dysfunction

Environmental enteric dysfunction (EED) is a subclinical syndrome of altered small intestinal function postulated to be an important contributor to childhood undernutrition. The role of small intestinal bacterial communities in the pathophysiology of EED is poorly defined due to a paucity of studies where there has been a direct collection of small intestinal samples from undernourished children. Sixty-three members of a Pakistani cohort identified as being acutely malnourished between 3 and 6 months of age and whose wasting (weight-for-length Z-score [WLZ]) failed to improve after a 2-month nutritional intervention underwent esophagogastroduodenoscopy (EGD). Paired duodenal luminal aspirates and duodenal mucosal biopsies were obtained from 43 children. Duodenal microbiota composition was characterized by sequencing bacterial 16S rRNA gene amplicons. Levels of bacterial taxa (amplicon sequence variants [ASVs]) were referenced to anthropometric indices, histopathologic severity in biopsies, expression of selected genes in the duodenal mucosa, and fecal levels of an immunoinflammatory biomarker (lipocalin-2). A "core" group of eight bacterial ASVs was present in the duodenal samples of 69% of participants. Streptococcus anginosus was the most prevalent, followed by Streptococcus sp., Gemella haemolysans, Streptococcus australis, Granulicatella elegans, Granulicatella adiacens, and Abiotrophia defectiva. At the time of EGD, none of the core taxa were significantly correlated with WLZ. Statistically significant correlations were documented between the abundances of Granulicatella elegans and Granulicatella adiacens and the expression of duodenal mucosal genes involved in immune responses (dual oxidase maturation factor 2, serum amyloid A, and granzyme H). These results suggest that a potential role for members of the oral microbiota in pathogenesis, notably Streptococcus, Gemella, and Granulicatella species, warrants further investigation.IMPORTANCEUndernutrition among women and children is a pressing global health problem. Environmental enteric dysfunction (EED) is a disease of the small intestine (SI) associated with impaired gut mucosal barrier function and reduced capacity for nutrient absorption. The cause of EED is ill-defined. One emerging hypothesis is that alterations in the SI microbiota contribute to EED. We performed a culture-independent analysis of the SI microbiota of a cohort of Pakistani children with undernutrition who had failed a standard nutritional intervention, underwent upper gastrointestinal tract endoscopy, and had histologic evidence of EED in their duodenal mucosal biopsies. The results revealed a shared group of bacterial taxa in their duodenums whose absolute abundances were correlated with levels of the expression of genes in the duodenal mucosa that are involved in inflammatory responses. A number of these bacterial taxa are more typically found in the oral microbiota, a finding that has potential physiologic and therapeutic implications.

Single-Cell Phenotyping of Extracellular Electron Transfer via Microdroplet Encapsulation

Electroactive organisms contribute to metal cycling, pollutant removal, and other redox-driven environmental processes. Studying this phenomenon in high-throughput is challenging since extracellular reduction cannot easily be traced back to its cell of origin within a mixed population. Here, we describe the development of a microdroplet emulsion system to enrich EET-capable organisms. We validated our system using the model electroactive organism S. oneidensis and describe the tooling of a benchtop microfluidic system for oxygen-limited processes. We demonstrated enrichment of EET-capable phenotypes from a mixed wild-type and EET-knockout population. As a proof-of-concept application, bacteria were collected from iron sedimentation from Town Lake (Austin, TX) and subjected to microdroplet enrichment. We observed an increase in EET-capable organisms in the sorted population that was distinct when compared to a population enriched in a bulk culture more closely akin to traditional techniques for discovering EET-capable bacteria. Finally, two bacterial species, C. sakazakii and V. fessus not previously shown to be electroactive, were further cultured and characterized for their ability to reduce channel conductance in an organic electrochemical transistor (OECT) and to reduce soluble Fe(III). We characterized two bacterial species not previously shown to exhibit electrogenic behavior. Our results demonstrate the utility of a microdroplet emulsions for identifying putative EET-capable bacteria and how this technology can be leveraged in tandem with existing methods.

Arteriovenous Graft Infection Due to Granulicatella adiacens

Granulicatella adiacens is a gram-positive coccus that is normally found in the human oral cavity and gastrointestinal and urogenital tracts but can rarely cause infection. When it does cause infection, Granulicatella adiacens has been most associated with bacteremia and endovascular infection, but to our knowledge, there are no previously documented cases of arteriovenous graft (AVG) infection. We present a case of Granulicatella adiacens bacteremia with associated AVG infection.

Gut microbiota are differentially correlated with blood pressure status in African American collegiate athletes: A pilot study

Hypertension (HTN) is common among athletes and the most recent epidemiologic data reports that cardiovascular (CV) sudden death is significantly greater in African Americans (AAs). Gut microbial dysbiosis (a poorly diverse stool microbial profile) has been associated with HTN in sedentary people but microbial characteristics of athletes with HTN are unknown. Our purpose was to differentiate microbiome characteristics associated with BP status in AA collegiate athletes. Thirty AA collegiate athletes were stratified by normal BP (systolic BP (SBP) ≤130 mmHg; n = 15) and HTN (SBP ≥130 mmHg; n = 15). 16S rRNA gene sequencing was performed on stool samples to identify microbes at the genus level. We did not observe any significant differences in alpha diversity, but beta diversity was different between groups. Principal coordinate analysis was significantly different (PERMANOVA, p < 0.05, R = 0.235) between groups. Spearman rank correlations showed a significant (p < 0.05) correlation between systolic BP and abundances for Adlercreutzia (R = 0.64), Coprococcus (R = 0.49), Granulicatella (R = 0.63), and Veillonella (R = 0.41). Gut microbial characteristics were associated with differentially abundant microbial genus' and BP status. These results will direct future studies to define the functions of these microbes associated with BP in athletes.

Granulicatella seriolae sp. nov., a Novel Facultative Anaerobe Isolated from Yellowtail Marine Fish

A bacterial strain, designated as S8T, was isolated from the gut contents of Seriola quinqueradiata from the coastal sea area of Jeju Island, South Korea. The strain is a Gram-staining positive, non-motile, non-spore-forming, facultative anaerobic coccus. Optimal growth was observed at 30 °C, pH 8.0-9.0, and 0-0.5% w/v NaCl, under anaerobic conditions. The predominant fatty acids were C18:1 ω9c, C16:0, C18:0, and C16:1 ω9c, while quinone was not detected. The genome was 2,224,566 bp long, with a GC content of 38.2%. Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain S8T had 96.2% similarity with Granulicatella adiacens ATCC 49175T, its closest known species according to nomenclature. The DNA-DNA hybridization (dDDH), average nucleotide identity, and average amino acid identity values between strain S8T and G. adiacens ATCC 49175T were 25.7%, 85.5%, and 77.2%, respectively, all of which fall below the recommended threshold for species differentiation. Based on genomic, phenotypic, and phylogenetic evidence, we propose that strain S8T should be a novel species within the genus Granulicatella, for with the name Granulicatella seriolae sp. nov. is proposed. The type strain is S8T (KCTC 43438T = JCM 35604T).

Pediatric Cervicofacial Necrotizing Fasciitis-A Challenge for a Medical Team

Cervical necrotizing fasciitis is a very rare complication of a bacterial infection that can have a dental cause. This type of infection typically affects fascial plane, which has a poor blood supply and can affect soft tissue and cervical fascia and can spread quickly causing infection of mediastinum. Initially, in the first stage, the overlying tissues are unaffected, and this can delay diagnosis and surgical intervention. Incidence in children is extremely rare and can be frequently associated with various other general pathologies that decrease the immune system response. We present a case of a young 12-year-old boy diagnosed with this type of infection in the head and neck as a complication of a second inferior molar pericoronitis. The treatment and the management of the case was difficult not only due to the presence of the infection but also because of the prolonged intubation.

The media composition as a crucial element in high-throughput metabolic network reconstruction

In recent years, metagenome-assembled genomes (MAGs) have provided glimpses into the intra- and interspecies genetic diversity and interactions that form the bases of complex microbial communities. High-throughput reconstruction of genome-scale metabolic networks (GEMs) from MAGs is a promising avenue to disentangle the myriad trophic interactions stabilizing these communities. However, high-throughput reconstruction of GEMs relies on accurate gap filling of metabolic pathways using automated algorithms. Here, we systematically explore how the composition of the media (specification of the available nutrients and metabolites) during gap filling influences the resulting GEMs concerning predicted auxotrophies for fully sequenced model organisms and environmental isolates. We expand this analysis by using 106 MAGs from the same species with differing quality. We find that although the completeness of MAGs influences the fraction of gap-filled reactions, the composition of the media plays the dominant role in the accurate prediction of auxotrophies that form the basis of myriad community interactions. We propose that constraining the media composition for gap filling through both experimental approaches and computational approaches will increase the reliability of high-throughput reconstruction of genome-scale metabolic models from MAGs and paves the way for culture independent prediction of trophic interactions in complex microbial communities.

Draft Genome Sequence of Granulicatella sp. Strain S8, Isolated from a Marine Fish, Seriola quinqueradiata

In this study, Granulicatella sp. strain S8 was isolated from the gut of a marine fish, Seriola quinqueradiata, and the draft genome was sequenced. Various genes responsible for pathogenesis, metabolite biosynthesis, defense, and lactic acid production were predicted. The genome sequence of this facultative anaerobe provides insights into its distinctive features.

RARE CASE OF ABIOTROPHIA DEFECTIVA BLEB-ASSOCIATED ENDOPHTHALMITIS

PURPOSE

To report a rare case of Abiotrophia defectiva bleb-associated endophthalmitis.

METHODS

In this case report of a patient with bleb-associated endophthalmitis, the authors describe the features of severe and rapid onset, associated retinitis, and a favorable outcome after aggressive early intervention.

RESULTS

A 75-year-old woman presented decreased visual acuity of hand motions with an elevated intraocular pressure of 39 mmHg in the left eye. Her ocular history was notable for severe primary open-angle glaucoma with uneventful trabeculectomy and cataract surgery in both eyes 7 years before. Examination revealed conjunctival injection and an opaque avascular cystic bleb along with anterior chamber cellular reaction with a B-scan ultrasound concerning for vitritis. A. defectiva was isolated from the vitreous tap within 48 hours and confirmed later with 16S ribosomal RNA sequencing. After initial vitreous tap and inject and subsequent pars plana vitrectomy, her best-corrected visual acuity had improved to 20/500 at postoperative week one and then improved to 20/40 at postoperative month 2. Her examination was notable for resolved corneal edema, a deep and quiet anterior chamber, and resolved intraretinal hemorrhages.

CONCLUSION

This is one of the first bleb-associated endophthalmitis cases with rapid identification of A. defectiva . A. defectiva was isolated from the initial vitreous tap within 48 hours and confirmed with 16S ribosomal RNA sequencing. This case highlights that rapid identification of A. defectiva may be indicative of a greater bacterial load and should prompt aggressive intervention and that the visual prognosis can be favorable.

Granulicatella spp., a Causative Agent of Infective Endocarditis in Children

Granulicatella spp. are non-motile, non-sporulating, facultatively anaerobic Gram-positive cocci. Throughout the literature, these organisms have been referred to by several names, such as “nutritionally deficient streptococci”, “vitamin-B dependent streptococci” and “pyridoxal-dependent streptococci”, because of their fastidious nutritional requirements, which can often make culture isolation challenging. Known to be a member of the normal microbiota of the human oral cavity and urogenital and intestinal tracts, similar to other streptococci, Granulicatella spp. can cause bacteremia, sepsis and infective endocarditis. Considering the difficulty in growing this organism on culture medium, the fact that it is now included among the bacteria known to be responsible for culture-negative infective endocarditis suggests that its pathogenic role could be highly underestimated. Moreover, being considered such a rare causative agent, it is not a target of standard antibiotic empiric treatment. We present a rare case of G. elegans endocarditis in a young child and review the medical literature on Granulicatella endocarditis in the pediatric population, with the aim of sharing knowledge about this microorganism, which can be challenging for a clinician who is not familiar with it.

Right-sided Infective Endocarditis with Ventricular Free Wall Vegetation Caused by Abiotrophia defectiva in a Patient with Unrepaired Ventricular Septal Defect

To our knowledge, there have been no reports of right-sided infective endocarditis (RSIE) with ventricular free wall vegetation caused by Abiotrophia defectiva. We herein report a case of RSIE caused by A. defectiva with ventricular free wall vegetation in a 27-year-old man with ventricular septal defect (VSD). Computed tomography showed multiple bilateral pulmonary nodular shadows. Transesophageal echocardiography (TEE) demonstrated right ventricular free wall vegetation at the jet stream. Blood culture revealed A. defectiva. These findings are consistent with a diagnosis of infective endocarditis and septic pulmonary embolism. Treatment with ceftriaxone and gentamicin and subsequent surgical VSD closure improved the patient's condition without recurrence.

Classification of salivary bacteriome in asymptomatic COVID-19 cases based on long-read nanopore sequencing

The coronavirus (COVID-19) global pandemic has impacted the health of almost everyone, including changes in their salivary microbiota. Since 2019, there has been an increase in the number of new COVID-19 cases in Thailand. Therefore, COVID-19 active case finding is important for early detection and epidemic control. Moreover, the dynamic changes of salivary bacteriome in asymptomatic COVID-19 cases are largely unknown. This research aimed to investigate and compare the salivary bacteriome and the co-infectious bacterial pathogens in the asymptomatic COVID-19 positive group to the negative group, based on novel nanopore sequencing. This cohort was a cross-sectional study including saliva samples collected from 82 asymptomatic participants (39 COVID-19 positive and 43 COVID-19 negative cases). All samples were sequenced for the full-length bacterial 16S rDNA. The alpha and beta diversity analyses were not significantly different between groups. The three major species in salivary bacteriome including Veillonella parvula, Streptococcus mitis, and Prevotella melaninogenica were observed in both groups. Interestingly, Lautropia mirabilis was a significantly enriched species in the saliva of the asymptomatic COVID-19-positive cases based on linear discriminant analysis effect size (LEfSe) analysis. The results suggested that L. mirabilis was a co-infectious agent in the asymptomatic COVID-19 group. However, the potential role of L. mirabilis should be validated in further experimental studies.

Granulicatella elegans infective endocarditis: A case report

Granulicatella elegans is a rare cause of infective endocarditis, accounting for 1–2% of all cases. It is well recognized that this pathogen can present in association with negative blood cultures. There are higher rates of both relapse and mortality compared with endocarditis caused by other bacteria. Microbiological diagnosis can be especially challenging because many conventional blood culture media lack pyridoxal, which can be found in automated blood culture broths like BACTEC™ or BACT/ALERT® and thus they may require ‘helper’ bacteria to be culture the organism. This current case report describes a 66-year-old male patient with a 10-year history of post-inflammatory combined aortic valve disease (moderate aortic stenosis and mild aortic regurgitation). He presented with a 3-month history of recurrent fever and general deterioration. Despite targeted, prolonged, combined antibiotic treatment with intravenous penicillin and gentamicin, surgery was eventually required. An aortic prosthetic valve implantation was performed with good results. In case of subacute endocarditis, especially when a causative organism proves difficult to detect, G. elegans should be considered. Identification is greatly enhanced by using polymerase chain reaction methods and this test should be considered in all cases of culture negative endocarditis.

Influence of Gallic Acid-Containing Mouth Spray on Dental Health and Oral Microbiota of Healthy Cats—A Pilot Study

Simple Summary

Periodontal diseases are common dental issues in cats. Oral care supplements were used to prevent diseases and maintain oral health. Moreover, maintaining a healthy oral microbiome is crucial for oral health. Therefore, we have developed a gallic acid-containing mouth spray and studied its effect on oral microbiota and dental health in healthy cats. The results revealed that the gingival and plaque indexes were improved after 42 days of mouth spray treatment in cats. The mouth spray treatment also reduced the abundance of harmful bacterial load and supported the growth of normal oral microbiota. This preliminary study recommended that the gallic acid-containing mouth spray could be an essential oral product to improve the oral hygiene of the cats.

Abstract

This pilot study aimed to investigate the effects of gallic acid-containing mouth spray on oral microbiota in healthy cat subjects. Forty healthy cats were recruited and randomly allocated to the control (G1; n = 20) and treatment groups (G2; n = 20). The cats were treated with mouth spray twice daily for 42 days. The changes in the gingival index (GI) and plaque index (PI) were measured at baseline (day 0) and end of the study (42nd day). The changes in the oral microbial composition of representative animals (control, n = 9; and treatment, n = 8) were also evaluated at baseline and end of the study. Oral microbial composition was assessed by amplifying the V1–V3 region of the 16S rRNA gene from supragingival dental plaque DNA extracts. The sequences were annotated using the QIIME 2.0. The GI and PI were significantly reduced after 42 days of treatment. The deep sequencing revealed that mouth spray influenced the cats’ oral microbiome and was significantly diverse. About 20 phyla and 59 species were observed after 42 days of mouth spray usage in cats’ oral microbiota. The number of operational taxonomic units (OTUs) of post-treatment samples (PoTS) of G2 was greatly reduced compared to other samples. Further analysis revealed that mouth spray acts substantially against Desulfomicrobium orale, one of the known pathogens in periodontal disease. The mouth spray efficiently reduced the growth of 22 species and uprooted 17 species. Moreover, the mouth spray supported the growth of normal oral microbiota, including Moraxella and Neisseria species. The preliminary study suggested that the gallic acids-containing mouth spray could be an essential oral product to improve the oral hygiene of the cats. Moreover, further studies are needed to confirm the beneficial effect of mouth spray on cats.

Granulicatella adiacens as an Unusual Cause of Empyema: A Case Report and Review of Literature

Granulicatella adiacens , a nutritionally variant Streptococcus (NVS), is part of the normal commensal flora of human mouth, genital, and intestinal tracts and rarely causes disease. It has been mostly reported from bacteremia and endocarditis cases, but rarely can cause vertebral osteomyelitis, pancreatic abscess, otitis media, and endovascular, central nervous system, ocular, oral, bone and joint, and genitourinary infections. Due to requirement of fastidious culture conditions and non-specific colony morphology, serious diagnostic difficulties may arise in cases of NVS infections. Here, we are reporting a rare fatal infection of G. adiacens presented with empyema complicated to sepsis and necrotizing fasciitis.

Clinicians should be aware of the pathogenic potential of Granulicatella adiacens (a normal commensal flora of human mouth, genital and intestinal tracts). Appropriate supplemented media and a reliable detection system should be used to identify these fastidious organisms. We present this rare case to bring awareness among clinicians regarding such a rare but potentially fatal infection.

Abiotrophia defectiva Infective Endocarditis: A Rare and Dangerous Cause of Endocarditis

Infective endocarditis is an uncommon heart infection, typically involving heart valves. Abiotrophia defectiva is a rare cause of endocarditis, typically found within the GI tract, and is usually difficult to isolate and requires specialized media. We report a case of Abiotrophia defectiva endocarditis following a root canal.

CASE REPORT OF ABIOTROPHIA DEFECTIVA ENDOPHTHALMITIS AFTER REPEATED INJECTIONS OF DEXAMETHASONE INTRAVITREAL IMPLANT (OZURDEX)

PURPOSE

To present a case of endophthalmitis caused by Abiotrophia defectiva after repeated injections of dexamethasone intravitreal implant (Ozurdex), in a patient already on systemic immunosuppressive therapy, and discuss the management of this challenging situation.

METHODS

Case report and review of literature.

RESULTS

A 70-year-old female patient with history of idiopathic pulmonary fibrosis presented for urgent evaluation due to left eye vision loss and mild discomfort 12 days after receiving her seventh dexamethasone implant injection. Ocular history was pertinent for recurrent macular edema resulting from a remote branch vein occlusion. Twelve days after her last injection, visual acuity decreased from 20/30 to counting fingers at 5 feet. Slit-lamp examination showed anterior chamber cell without fibrinoid membranes or hypopyon. Within hours, the patient's clinical appearance progressed. A vitreous tap followed by intravitreal injection of vancomycin (1 mg/0.1 mL) and ceftazidime (2.25 mg/0.1 mL) was performed. The culture from the vitreous sample revealed heavy growth of A. defectiva. Owing to limited improvement, patient was taken to the operating room, and the presence of a full-thickness scleral defect at the site of most recent dexamethasone implant injection was confirmed. Vitrectomy with removal of implant, closure of all sclerotomies, including nonhealing full-thickness scleral defect, and repeated intravitreal antibiotic injection were performed. At the 3-month follow-up, no inflammation was observed, but visual acuity remained poor.

CONCLUSION

Intravitreal dexamethasone implant-associated endophthalmitis in the setting of systemic immunosuppression is a rare and challenging situation. Both local and systemic immunosuppression may delay wound healing, predisposing to wound leakage and consequent endophthalmitis. Despite repeated intravitreal antimicrobial injection and vitrectomy with implant removal, A. defectiva endophthalmitis carried a poor visual outcome.

Aortic Valve Replacement and Penicillin Desensitization in a Patient with Abiotrophia defectiva Aortic Valve Endocarditis

Abiotrophia defectiva is an uncommon and insidious yet destructive cause of infective endocarditis preferentially treated with penicillin/gentamicin and often requiring surgical treatment. A 60-year-old man with penicillin anaphylaxis history presented with fevers and a nonspecific constellation of symptoms. He was ultimately diagnosed with bicuspid aortic valve infective endocarditis based on blood cultures growing A.defectiva and echocardiographic evidence of bicuspid aortic valve, severe valvular regurgitation, and 5 × 7 mm vegetation. Aortic valve replacement and culture yielded penicillin-sensitive A.defectiva. After successful penicillin desensitization, antibiotic therapy was switched from vancomycin/gentamicin to benzylpenicillin. This is the first published case of penicillin desensitization in a patient with A.defectiva-associated infection. Penicillin desensitization, optimal antibiotic therapy, prompt aortic valve replacement, and close collaboration between cardiology and various other specialties were essential in achieving a positive outcome.

Lung abscess secondary to lung cancer with a coinfection of Granulicatellaadiacens and other bacteria: a case report

Background

Granulicatella adiacens is facultative anaerobic Gram-positive bacteria, which mainly involve bacterial endocarditis and bacteremia, but there are few reports of local suppurative infection. A case of lung abscess with a coinfection of Granulicatella adiacens and other bacteria in a lung cancer patient will be reported in this paper. To our knowledge, this is the first case report describing lung abscess due to G.adiacens.

Case presentation

A 52-year-old Chinese woman was admitted to the hospital, She complained of coughing and expectoration for 1 month, shortness of breath for half a month, and dyspnea for 1 day. After a series of examinations, she was diagnosed with lung abscess, pleural effusion, and bronchogenic carcinoma. Draining pus culture demonstrated Granulicatella adiacens. After more than 5 weeks of antibiotic therapies in total, she gradually recovered to fight against lung cancer.

Conclusion

This is the first reported lung abscess caused by G.adiacens. In immunosuppressed hosts, G.adiacens is a virulent pathogen associated with a spectrum of intrathoracic suppurative. Earlier diagnosis and proper drainage surgery with effective antibiotics treatment are very important, and antimicrobial treatment should be more than 5 weeks. When complex pulmonary infection interferes with the CT diagnosis, clinical suspicion of lung cancer should be increased if G.adiacens or Eikenella corrodens is detected from a pulmonary infection.

Granulicatella Adiacens as an Unusual Cause of Microbial Keratitis and Endophthalmitis: A Case Series and Literature Review

Purpose: To report two cases of microbial keratitis and/or endophthalmitis involving Granulicatella adiacens.Methods: Case series.Results: 24-year-old female with a history of Herpes simplex virus 1 (HSV-1) and Candida parapsilosis keratitis presented with a geographic epithelial defect and infiltrate in the left eye. Cultures were positive for HSV-1 and G. adiacens. Keratitis resolved with topical vancomycin and oral valacyclovir. A 65-year-old female with a history of type II diabetes and failed therapeutic penetrating keratoplasty presented with inferior corneal graft haze and vitreous inflammation of the right eye. Therapeutic penetrating keratoplasty and pars plana vitrectomy were performed, and the corneal button returned positive for G. adiacens. The patient was treated with topical and intravitreal vancomycin as well as topical and systemic steroids.Conclusions: These cases expand the literature on G. adiacens keratitis and endophthalmitis and corroborate the role of steroid use and prior surgery as paramount risk factors.

In vitro antimicrobial activity against Abiotrophia defectiva and Granulicatella elegans biofilms

OBJECTIVES

To determine the efficacy of different antibiotics (alone or in combination) against Abiotrophia defectiva and Granulicatella elegans biofilms and to investigate the anti-biofilm activity of gentamicin alone versus blood culture isolates from both species.

METHODS

The activity of benzylpenicillin, clindamycin, daptomycin, fosfomycin, gentamicin, levofloxacin and rifampicin against 24-hour-old biofilms of A. defectiva and G. elegans was investigated in vitro by conventional microbiological methods and isothermal microcalorimetry.

RESULTS

For planktonic bacteria, the MIC values of tested antibiotics ranged from 0.016 to 64 mg/L, as determined by microcalorimetry. Higher antibiotic concentrations, ranging from 1 to >1024 mg/L, were needed to produce an effect on biofilm bacteria. Gentamicin was an exception as it was active at 1 mg/L against both planktonic and biofilm G. elegans. A synergistic effect was observed when daptomycin was combined with benzylpenicillin, gentamicin or rifampicin against A. defectiva biofilms and when gentamicin was combined with rifampicin or levofloxacin against G. elegans biofilms. A. defectiva clinical isolates displayed greater variability in gentamicin susceptibility as compared with G. elegans strains.

CONCLUSIONS

Antimicrobial susceptibility profiles vary widely between Abiotrophia and Granulicatella biofilms, and synergistic effects of the tested antibiotics were heterogeneous. The clinical relevance of these in vitro observations needs to be confirmed in experimental in vivo conditions and human trials, before guidelines for the treatment of A. defectiva and G. elegans infections are established. This study suggests the benefit of further clinical exploration of antibiotic combinations with anti-biofilm effect.

Abiotrophia defectiva as a cause of infective endocarditis with embolic complications in children

Abiotrophia defectiva is a rare pathogen of infective endocarditis (IE) but is frequently involved in embolic complication and valvular dysfunction. IE caused by A. defectiva in children is poorly studied. This study reports four cases of A. defectiva IE in children and reviews previously reported five pediatric cases of A. defectiva IE. Most of the patients presented with a subacute course, with prolonged fever or atypical symptoms. Eight patients had embolic complications at presentation. All nine children were treated with combination antimicrobial therapy and six of them received surgical intervention. All patients recovered well without relapse. A. defectiva should be considered in children with infective endocarditis, especially in those with atypical presentations. As complications are frequent and more than half of the patients need surgical treatment, prompt diagnosis along with appropriate treatment is necessary.

Infective endocarditis caused by Abiotrophia defectiva presenting as anterior mitral leaflet perforation mimicking cleft anterior mitral leaflet

Infective endocarditis (IE) is primarily a bacterial infection of the heart valves. The most common organisms implicated include Staphylococcus and Streptococcus species. However, with the advent of MALDI-TOF and molecular techniques, the reports of IE being caused by rare organisms are on a rise. Here we describe a case of IE due to Abiotrophia defectiva. This is the first report of simultaneous infection of both mitral and aortic valves by Abiotrophia defectiva from India. IE caused by Abiotrophia defectiva has been seen to be more severe, associated with higher failure rates and relapse. This emphasizes the accurate identification of nutritionally variant Streptococcus (NVS) species as the management of choice varies between Abiotrophia and Granulicatella.

Granulicatella adiacens abscess: Two rare cases and review

Granulicatella adiacens is a nutritionally variant streptococcus species. These bacteria are rarely isolated in the laboratory due to their fastidious growth requirements. These have been mostly reported from bloodstream infections, infective endocarditis, infections of orbit, nasolacrimal duct and breast implants. Here, we are reporting two cases of subcutaneous abscesses caused by G. adiacens. In first case, it was isolated from abscess around elbow joint and second case was a suprapatellar abscess. We have also reviewed the published data concerning diagnosis and antimicrobial susceptibility pattern of Granulicatella infections and included some Indian cases.

Risk for Endocarditis in Bacteremia With Streptococcus-Like Bacteria: A Retrospective Population-Based Cohort Study

Background

Many genera and species of Streptococcus-like bacteria (SLB) can cause infective endocarditis (IE), but little is known about the epidemiology of and the risk factors for IE in SLB-bacteremia. The aim of the study was to analyze this in a cohort of patients with SLB-bacteremia, focusing on Abiotrophia, Aerococcus, Gemella, and Granulicatella. We also evaluated whether published scoring systems generated for other Gram-positive bacteria known to cause IE (HANDOC for streptococci and NOVA and DENOVA for enterococci) could be used in SLB bacteremia to decide whether transesophageal echocardiography (TEE) could be omitted.

Methods

Positive blood cultures with SLB were retrieved from population-based registries in Sweden (3.2 million inhabitants), from January 2012 to December 2017. Clinical data were collected from medical records. Risk factors for IE were analyzed and the performances of the scoring systems were calculated.

Results

The incidence of bacteremia with the 4 SLB genera was 30 episodes/1 000 000 population per year, of which Aerococcus contributed with 18. Among 568 episodes of bacteremia, 32 cases of IE were identified (5.6%). Infective endocarditis was most common in bacteremia with Abiotrophia (4 of 19) followed by Granulicatella (9 of 124), Gemella (6 of 87), and Aerococcus (13 of 338). NOVA had 100% sensitivity to identify IE but a low specificity (15%). For HANDOC and DENOVA, the sensitivities were 97% and 91%, respectively, whereas specificities were 85% and 90%, respectively, and numbers needed to screen were 3.6 and 2.8, respectively.

Conclusions

Bacteremia with these SLB is relatively rare, and the decision whether TEE should be performed or not could be based on either HANDOC or DENOVA.

Infective endocarditis due to Granulicatella elegans presenting with musculoskeletal symptoms

A 62-year-old man with essential hypertension and right L4-L5 hemilaminectomy was referred to rheumatology for evaluation of severe arthralgia and myalgia for 12 months. Review of symptoms was significant for night sweats and 20 pounds unintentional weight loss. Physical examination was significant for holosystolic murmur best heard at the cardiac apex of unclear chronicity. Laboratory investigations revealed elevated inflammatory markers, white blood cell count and B-type natriuretic peptide. Transoesophageal echocardiogram showed flail posterior mitral leaflet with severe mitral regurgitation and two vegetations (2.5×1 cm and 1.6×0.3 cm). Abdominal CT showed new focal splenic infarcts, and a brain MRI revealed subacute infarcts, consistent with the embolic phenomenon. Blood cultures grew Granulicatella elegans The patient underwent mitral valve replacement surgery followed by 6 weeks of parenteral therapy with vancomycin and gentamicin, with full recovery at a 3-month follow-up.

Streptococcus pneumoniae Evades Host Cell Phagocytosis and Limits Host Mortality Through Its Cell Wall Anchoring Protein PfbA

Streptococcus pneumoniae is a Gram-positive bacterium belonging to the oral streptococcus species, mitis group. This pathogen is a leading cause of community-acquired pneumonia, which often evades host immunity and causes systemic diseases, such as sepsis and meningitis. Previously, we reported that PfbA is a β-helical cell surface protein contributing to pneumococcal adhesion to and invasion of human epithelial cells in addition to its survival in blood. In the present study, we investigated the role of PfbA in pneumococcal pathogenesis. Phylogenetic analysis indicated that the pfbA gene is highly conserved in S. pneumoniae and Streptococcus pseudopneumoniae within the mitis group. Our in vitro assays showed that PfbA inhibits neutrophil phagocytosis, leading to pneumococcal survival. We found that PfbA activates NF-κB through TLR2, but not TLR4. In addition, TLR2/4 inhibitor peptide treatment of neutrophils enhanced the survival of the S. pneumoniae ΔpfbA strain as compared to a control peptide treatment, whereas the treatment did not affect survival of a wild-type strain. In a mouse pneumonia model, the host mortality and level of TNF-α in bronchoalveolar lavage fluid were comparable between wild-type and ΔpfbA-infected mice, while deletion of pfbA decreased the bacterial burden in bronchoalveolar lavage fluid. In a mouse sepsis model, the ΔpfbA strain demonstrated significantly increased host mortality and TNF-α levels in plasma, but showed reduced bacterial burden in lung and liver. These results indicate that PfbA may contribute to the success of S. pneumoniae species by inhibiting host cell phagocytosis, excess inflammation, and mortality by interacting with TLR2.

Granulicatella adiacens and Abiotrophia defectiva Native Vertebral Osteomyelitis: Three Cases and Literature Review of Clinical Characteristics and Treatment Approach

Granulicatella adiacens and Abiotrophia defectiva are an increasingly recognized cause of osteoarticular infections. We describe two cases of G. adiacens and one case of A. defectiva native vertebral osteomyelitis (NVO) and review all published cases. Nine cases of G. adiacens NVO and two cases of A. defectiva NVO were previously described. Patients were usually middle-aged men, and classical risk factors for NVO were present in half of the cases. Concomitant bacteremia was reported in 78.6% of cases, and concurrent infective endocarditis occurred in 36.4% of this sub-group of patients. Many different antibiotic schemes were recorded, with median treatment duration of 6 weeks. In the most recent reports, glycopeptides represented the most frequent empirical therapy, possibly due to the increasing emergence of G. adiacens and A. defectiva penicillin-resistant strains. Stabilization surgery was rarely required (14.3% of cases), and clinical cure was generally achieved. In conclusion, Granulicatella spp. and Abiotrophia spp. NVO is rare but increasingly described. A total antibiotic course of six weeks seems to be appropriate for noncomplicated cases, and clinical outcome is generally favorable.

Trivalvular infective endocarditis secondary to Granulicatella adiacens and Peptostreptococcus spp

We present a case of a 42-year-old Caucasian man that came to our facility complaining of dyspnea and subjective fevers and was found to have infective endocarditis. His blood cultures initially grew Peptostreptococcus spp and he was started on penicillin and gentamicin. Repeat blood cultures, drawn 48 h later, became positive for Granulicatella adiacens. Vancomycin was added at this point, given reports of growing penicillin resistance of Granulicatella spp. Transthoracic echocardiogram showed multiple vegetations on the aortic, mitral and tricuspid valves. The patient’s final antibacterial regimen consisted of intravenous penicillin G 24 million units daily and vancomycin (goal trough of 15–20) for a total of 6 weeks. The first 2 weeks of his regimen also included gentamicin. The patient was not considered for valve replacement surgery given concern for continued use of illicit intravenous drugs. Peptostreptococcus species are anaerobic, non-spore forming, gram-positive cocci, thought to generally have a subacute clinical presentation. Granulicatella genus is nutritionally deficient bacteria which require a supplemented media in order to grow. Both of these bacteria are present in the mouth and gastrointestinal flora. The rate of infective endocarditis from anaerobic species has been reported up to 16%, which includes multiple species. While on nutritionally deficient bacteria are reported to be involved on infective endocarditis in the range of 3–8%. Antimicrobial resistance is on the rise for both of these species, which makes the appropriate choice of antimicrobials quite important.

Proteomic Analysis and Virulence Assessment of Granulicatella adiacens Secretome

Despite reports on the occurrence of Granulicatella adiacens in infective endocarditis, few mechanistic studies on its virulence characteristics or pathogenicity are available. Proteins secreted by this species may act as determinants of host-microbe interaction and play a role in virulence. Our aim in this study was to investigate and functionally characterize the secretome of G. adiacens. Proteins in the secretome preparation were digested by trypsin and applied to nanoLC-ESI-MS/MS. By using a combined mass spectrometry and bioinformatics approach, we identified 101 proteins. Bioinformatics tools predicting subcellular localization revealed that 18 of the secreted proteins possessed signal sequence. More than 20% of the secretome proteins were putative virulence proteins including serine protease, superoxide dismutase, aminopeptidase, molecular chaperone DnaK, and thioredoxin. Ribosomal proteins, molecular chaperones, and glycolytic enzymes, together known as "moonlighting proteins," comprised fifth of the secretome proteins. By Gene Ontology analysis, more than 60 proteins of the secretome were grouped in biological processes or molecular functions. KEGG pathway analysis disclosed that the secretome consisted of enzymes involved in biosynthesis of antibiotics. Cytokine profiling revealed that secreted proteins stimulated key cytokines, such as IL-1β, MCP-1, TNF-α, and RANTES from human PBMCs. In summary, the results from the current investigation of the G. adiacens secretome provide a basis for understanding possible pathogenic mechanisms of G. adiacens.

Cardiogenic and septic shock associated with aortic and mitral valve infective endocarditis caused by Abiotrophia Defectiva from a urinary tract infection

Abiotrophia defectiva, also known as nutritionally variant streptococcus, is part of the normal flora of the oral cavity and urogenital and intestinal tracts and is a rare cause of infective endocarditis. It is fastidious or difficult to culture and associated with high rates of septic embolization, treatment failure and mortality. We describe an unusual presentation of infective endocarditis with severe mitral valve regurgitation due to Abiotrophia defectiva in an immunocompetent patient. After a complicated hospital course, surgical replacement of both the mitral and aortic valves was performed. We suggest that this patient likely had subacute infective endocarditis before diagnosis and treatment of her urinary tract infection, and following treatment failure, she developed life-threatening infective endocarditis. This case report highlights that patients with Abiotrophia defectiva infections are at high risk for infective endocarditis and that the clinical progression from this infection can be slow, with difficulty isolating the pathogen, which can significantly impact patient outcome.

Rare but Not Infrequent: Infective Endocarditis Caused by Abiotrophia defectiva

Endocarditis (IE) is defined by an infection of a native or prosthetic heart valve, the mural endocardium, or an indwelling cardiac device. Although viridan-group streptococci (VGS) and Staphylococci species have collectively been considered as the most common cause of endocarditis, uncommon pathogens may also lead to the disease with significant morbidity and mortality. Abiotrophia defectiva, a nutritionally variant streptococci (NVS), is a virulent bacterium that preferentially affects endovascular structure and is implicated in many culture-negative endocarditis with dreadful complications such as heart failure, septic embolization, and valve destruction. Here, we report a case of a 60-year-old male patient, with a past medical history significant for hypertrophic obstructive cardiomyopathy, who was incidentally found to have mitral valve vegetative mass with an uncommon agent, A. defectiva. The patient was successfully treated with antimicrobial therapy. The objective of this article is to describe the possibility of uncommon cause of common diseases and raises awareness of infective endocarditis caused by A. defectiva among clinicians and microbiologists. Early and proper identification of this pathogen is important to achieve a better outcome.

Bacterial diversity of artisanal cheese from the Amazonian region of Brazil during the dry and rainy seasons

The microbiota from artisanal cheeses produced in the Amazonian region is evaluated. Samples of artisanal cheeses were obtained from markets in Conceição do Araguaia and Redenção (Pará, Brazil) over rainy and dry seasons, and their biodiversity was assessed by culture-dependent and culture-independent methods. Mean counts of lactic acid bacteria (LAB) in cheeses ranged from 7.32 to 8.84 log CFU/g, for both seasons. Members of genera Lactobacillus, Lactococcus, Weissella, Enterococcus, Pediococcus, and Leuconostoc were predominant. The amplification of the 16S rRNA V6-V9 region, followed by a temporal temperature-gradient gel electrophoresis (TTGE) and sequencing of the TTGE bands revealed important differences in the microbial composition variability between samples from the two seasons and among cheese samples analyzed. TTGE showed the presence of microorganisms that are frequently found in cheese, such as L. lactis subsp. lactis, as well as other non-usual species, such as Macrococcus caseolyticus and Corynebacterium variabile. Moreover, TTGE analysis revealed the presence of microorganisms that have been isolated from other types of foods (Paralactobacillus selangorenses) along with some not usually found in foods, such as Exiguobacterium acetylicum, plus the presence of pathogenic microorganisms (Granulicatella elegans and Aerococcus sanguinicola). The present molecular approaches combined with culture-dependent methods provided a more detailed description of the microbial ecology of traditional cheeses from the Amazonian region in northern Brazil.

Septic arthritis caused by Granulicatella adiacens after anterior cruciate ligament reconstruction

Septic arthritis after knee arthroscopy is an extremely rare condition. A rate of 0.15-0.84% cases of postoperative infection is estimated in several series. The arthroscopy procedure most frequently related with an infectious complication is anterior cruciate ligament (ACL) reconstruction, with a prevalence of 0.3-1.7% cases. Staphylococcus sp. is the pathogen most commonly cultured. We describe a case of septic arthritis after ACL reconstruction. We found no published case of septic arthritis caused by this microorganism after knee arthroscopy. It is probably the first case published in the literature.

Cytokine induction of peripheral blood mononuclear cells by biofilms and biofilm supernatants of Granulicatella and Abiotrophia spp

Granulicatella and Abiotrophia species are the normal oral flora bacteria that can occasionally cause infective endocarditis. Although substantial data exists in the literature demonstrating occurrence of these species in infective endocarditis, only a few mechanistic studies on their pathogenicity are found. The aim of this study was to investigate the ability of Granulicatella and Abiotrophia species to elicit immune response from human peripheral blood mononuclear cells (PBMC). Biofilms and biofilm supernatants of Granulicatella elegans CCUG 38949, Granulicatella adiacens CCUG 27809 and Abiotrophia defectiva CCUG 27639 were used to stimulate PBMCs for 24 h. Cytokines produced were first screened using a human cytokine membrane array kit. Further, pro-inflammatory cytokines TNF-α, IL-β, and IL-17 were quantified by ELISA. The cytokine profiler array showed the induction of 15 different cytokines/chemokines including IL-1β, IL-6, IL-8, TNF-α, MCP-1, MIP-1α/MIP-1β and RANTES. ELISA quantification revealed that G. adiacens biofilm induced significantly higher (P < 0.05) levels of IL-1β, i.e., 1931 (183) pg/ml than G. elegans or A. defectiva. However, in the case of biofilm supernatants A. defectiva was the strongest, inducing 2104 (574) pg/ml. Biofilm supernatants, but not biofilms from all three species induced TNF-α only weakly. IL-17 was undetectable from any of the stimulated samples. In conclusion, Granulicatella and Abiotrophia are potent inducers of inflammatory mediators from human PBMCs. However, biofilms and biofilm supernatants from these species seem to selectively elicit stimulation of certain cytokines.

Endocarditis due to Abiotrophia defectiva, a biofilm-related infection associated with the presence of fixed braces: A case report

RATIONALE

Endocarditis with Abiotrophia defectiva represents 4.3% to 6% of all streptococcal endocarditis. The article presents diagnosis issues and the complexity of the treatment.

PATIENT CONCERNS

We present the case of a female white patient, aged 26 years, who developed infectious endocarditis caused by A defectiva, in the last trimester of pregnancy, a biofilm-related infection associated with the presence of fixed braces.

DIAGNOSES

The diagnosis of infectious endocarditis was confirmed by the cardiac ultrasound examination that revealed a voluminous vegetation on the mitral valve, and acute mitral regurgitation caused by chordae tendinae rupture, and also by isolating Abiotrophia defectiva from two positive blood cultures.

INTERVENTIONS

The decision to undergo surgical intervention was taken, and a mitral valve replacement was performed. Surgical intervention that was associated with board-spectrum antibiotic therapy.

OUTCOMES

A defectiva, remains a rare cause of infective endocarditis, with a reserved prognosis that is motivated by the extensive valvular lesions and the risk of embolism.

LESSONS

The use of antibiotics administered in association, in the management of infective endocarditis, is mandatory.

Lumbar Spine Infection by Granulicatella and Abiotrophia Species

BACKGROUND

The Granulicatella and Abiotrophia species are streptococci and natural inhabitants of the oral and urogenital flora. They are uncommonly associated with human pathology, although they can cause septicemia, endocarditis, or bacteremia. These microorganisms are difficult to culture and identify due to particular microenvironment requirements. Rarely, presentation is osteomyelitis or infections of the spine.

CASE DESCRIPTION

The case report referenced patient notes, laboratory values, and imaging from the electronic health record. In this 48-year-old male with a history of hepatitis C and intravenous drug use, back pain was a relatively common presentation of an uncommon infection. His hospital course was significant for low back pain that did not resolve with conservative measures. Imaging was concerning for infection of the lumbar spine. Biopsies, negative early on, were ultimately positive for Granulicatella and Abiotrophia species, a rare infectious etiology. This infection uncommonly affects the lumbar spine and has not been previously documented in IV drug users. Intravenous antibiotics were prescribed for 6 weeks, after which the patient demonstrated significant clinical improvement.

CONCLUSION

With such an uncommon pathogen, there are no universal protocol changes indicated. However, awareness of such unusual microbes and their potential role as the etiology of more common infections, such as lumbar osteomyelitis, is crucial in developing a thorough infectious workup in cases resistant to treatment targeting typical microorganisms.

Aorto-right ventricular fistula: a rare complication of Abiotrophia Endocarditis

A 41-year-old African male presented with worsening dyspnea and cachexia concerning for congestive heart failure. Transesophageal echocardiogram revealed a large mass attached to the aortic valve leaflet, mass attached to the flail anterior mitral valve leaflet, severe pulmonary hypertension and dilatation of the aortic root along with fistula between the right coronary aortic cusp and the right ventricular (RV) outflow tract. Blood cultures grew Abiotrophia Defectiva (AD) sensitive to vancomycin. Patient underwent emergent surgical closure of aorto RV fistula and aortic root replacement along with pulmonary and mitral valve replacement. Endocarditis caused by AD has been reported to result in heart failure, septic embolization and destruction of the valve despite use of appropriate antibiotics. To our knowledge, this is the only case of AD endocarditis without any identified entrance route; requiring replacement of pulmonary, mitral and aortic valve due to extensive valvular damage and large vegetations.

Impact of enzymatic digestion on bacterial community composition in CF airway samples

Background

Previous studies have demonstrated the importance of DNA extraction methods for molecular detection of Staphylococcus, an important bacterial group in cystic fibrosis (CF). We sought to evaluate the effect of enzymatic digestion (EnzD) prior to DNA extraction on bacterial communities identified in sputum and oropharyngeal swab (OP) samples from patients with CF.

Methods

DNA from 81 samples (39 sputum and 42 OP) collected from 63 patients with CF was extracted in duplicate with and without EnzD. Bacterial communities were determined by rRNA gene sequencing, and measures of alpha and beta diversity were calculated. Principal Coordinate Analysis (PCoA) was used to assess differences at the community level and Wilcoxon Signed Rank tests were used to compare relative abundance (RA) of individual genera for paired samples with and without EnzD.

Results

Shannon Diversity Index (alpha-diversity) decreased in sputum and OP samples with the use of EnzD. Larger shifts in community composition were observed for OP samples (beta-diversity, measured by Morisita-Horn), whereas less change in communities was observed for sputum samples. The use of EnzD with OP swabs resulted in significant increase in RA for the genera Gemella (p < 0.01), Streptococcus (p < 0.01), and Rothia (p < 0.01). Staphylococcus (p < 0.01) was the only genus with a significant increase in RA from sputum, whereas the following genera decreased in RA with EnzD: Veillonella (p < 0.01), Granulicatella (p < 0.01), Prevotella (p < 0.01), and Gemella (p = 0.02). In OP samples, higher RA of Gram-positive taxa was associated with larger changes in microbial community composition.

Discussion

We show that the application of EnzD to CF airway samples, particularly OP swabs, results in differences in microbial communities detected by sequencing. Use of EnzD can result in large changes in bacterial community composition, and is particularly useful for detection of Staphylococcus in CF OP samples. The enhanced identification of Staphylococcus aureus is a strong indication to utilize EnzD in studies that use OP swabs to monitor CF airway communities.

Abiotrophia defectiva endarteritis with infective spondylodiscitis in an adult patient with patent ductus arteriosus

Endarteritis is a major complication in patients with patent ductus arteriosus, causing significant morbidity and mortality. We report an adult patient with asymptomatic patent ductus arteriosus and endarteritis involving the main pulmonary artery and secondary infective spondylodiscitis at the L5-S1 intervertebral disc caused by Abiotrophia defectivaA. defectiva, commonly referred to as nutritionally variant streptococci, cannot be identified easily by conventional blood culture techniques from clinical specimens. Its isolation was confirmed by 16S ribosomal RNA sequencing. The patient was successfully managed with a combination of penicillin G and gentamicin, pending surgical repair of the patent ductus arteriosus.

Antimicrobial Susceptibility Patterns among a Large, Nationwide Cohort of Abiotrophia and Granulicatella Clinical Isolates

Antimicrobial susceptibility patterns from 599 A. defectiva, G. adiacens, and G. elegans clinical isolates were determined by broth microdilution. We observed significant differences in susceptibility across species, particularly to penicillin and ceftriaxone, and across geographical regions. A. defectiva was the least susceptible species overall to penicillin. All isolates were susceptible to vancomycin and >90% were susceptible to levofloxacin.

A Dual Case of Peritonitis and Central Nervous System Infection Caused by Nutritionally Variant Streptococcal Species

Nutritional variant streptococci (NVS) are difficult to identify bacteria that can cause invasive infections such as endocarditis and meningitis. NVS as a cause of peritonitis has not been routinely described. This case of NVS as the etiology of peritonitis associated with previous neurosurgery and ventriculoperitoneal (VP) shunt revision demonstrates its potential role as a significant pathogen in patients with peritonitis and VP shunts. Therapy consists of vancomycin plus a second agent but since there are no standards for susceptibility testing, clinical response remains the standard for determining the efficacy of treatment. When there is central nervous system (CNS) involvement it is important to include drugs with appropriate CNS penetration.

An unusual case of thoracic empyema caused by Granulicatella elegans (nutritionally variant streptococci) in a patient with pulmonary tuberculosis and human immunodeficiency virus infection

INTRODUCTION

Nutritionally variant streptococci (NVS) are an infrequent cause of human infection with Granulicatella elegans being the least encountered species in clinical specimens. The most common infection caused by NVS is infective endocarditis.

CASE PRESENTATION

We report an unusual case of thoracic empyema due to G. elegans in a patient with pulmonary tuberculosis (TB) and human immunodeficiency virus infection. The patient responded favourably to drainage and penicillin.

CONCLUSION

This case illustrates that even though TB is responsible for the majority of pleural effusions in this setting, other rare opportunistic bacteria may cause infection in susceptible patients. Therefore, microbiological investigations should be performed in all patients presenting with pleural effusion.