Morbidity and mortality attributable to Rothia bacteremia in neutropenic and nonneutropenic patients

Ocular Bacterial Infections: A Ten-Year Survey and Review of Causative Organisms Based on the Oklahoma Experience

Ocular infections can be medical emergencies that result in permanent visual impairment or blindness and loss of quality of life. Bacteria are a major cause of ocular infections. Effective treatment of ocular infections requires knowledge of which bacteria are the likely cause of the infection. This survey of ocular bacterial isolates and review of ocular pathogens is based on a survey of a collection of isolates banked over a ten-year span at the Dean McGee Eye Institute in Oklahoma. These findings illustrate the diversity of bacteria isolated from the eye, ranging from common species to rare and unique species. At all sampled sites, staphylococci were the predominant bacteria isolated. Pseudomonads were the most common Gram-negative bacterial isolate, except in vitreous, where Serratia was the most common Gram-negative bacterial isolate. Here, we discuss the range of ocular infections that these species have been documented to cause and treatment options for these infections. Although a highly diverse spectrum of species has been isolated from the eye, the majority of infections are caused by Gram-positive species, and in most infections, empiric treatments are effective.

Microbiome Analysis and Pharmacovigilance After Inhaled Glucocorticoid: Oral Dysbiosis With the Isolation of Three Rothia Species and Subsequent Sjögren's Syndrome

Background: Treatment of respiratory tract diseases with inhaled glucocorticoids is a form of therapy that has been used for many years. It shows lower potency of side effects; nevertheless, microbiome change, sinopulmonary dysbiosis, secondary immunodeficiency, and immunomodulatory effects are underestimated. The latest guideline recommendations introduce the use of empirical antibiotic and/or multiplying inhaled glucocorticoids in therapeutic intervention of asthma and chronic pulmonary obstructive disease. Aims and objectives: The aim of the study was to describe a simple, universal, and cost-effective method of microbiome analysis for clinical trials. Such a general method for monitoring pharmacovigilance should be widely available and reliable. Methods: The study material included two kinds of swabs, taken from the same mouth ulcerations of patients with asthma treated with a temporary quadruple dose of fluticasone. The microbiological investigation was performed, and identification of the isolates was carried out using the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) Biotyper. Results: The analysis of dry swab demonstrated the presence of typical oral bacteria (Neisseria spp. and Streptococcus spp.), alongside with the potentially pathogenic Actinomyces spp. and three different Rothia species, identified simultaneously: R. aeria, R. dentocariosa, and R. mucilaginosa. Although quadrupled dose of corticoids was discontinued and ulcer healing was observed, the patients required topical therapy for maintained xerostomia. Progressive systemic autoimmunity (seronegative Sjögren's syndrome with major organ involvement) was observed later. Conclusion: Topical steroids (especially in quadruple dose) require attention to safety, immunomodulation, and microbiological outcome. They showed systemic side effects: microbiome alteration, humoral (IgG) immunodeficiency, and systemic autoimmunity. Isolation of three species of Rothia from a patient with mouth ulcers after steroid therapy suggests their participation in infectious and inflammatory processes. The proposed a methodology using MALDI-TOF-MS may be a prototype approach for microbial diagnostics in clinical trials of immunomodulatory drugs.

Fluoroquinolones' Biological Activities against Laboratory Microbes and Cancer Cell Lines

Development of novel derivatives to rein in and fight bacteria have never been more demanding, as microbial resistance strains are alarmingly increasing. A multitude of new fluoroquinolones derivatives with an improved spectrum of activity and/or enhanced pharmacokinetics parameters have been widely explored. Reporting novel antimicrobial agents entails comparing their potential activity to their parent drugs; hence, parent fluoroquinolones have been used in research as positive controls. Given that these fluoroquinolones possess variable activities according to their generation, it is necessary to include parent compounds and market available antibiotics of the same class when investigating antimicrobial activity. Herein, we provide a detailed guide on the in vitro biological activity of fluoroquinolones based on experimental results published in the last years. This work permits researchers to compare and analyze potential fluoroquinolones as positive control agents and to evaluate changes occurring in their activities. More importantly, the selection of fluoroquinolones as positive controls by medicinal chemists when investigating novel FQs analogs must be correlated to the laboratory pathogen inquest for reliable results.

Rothia mucilaginosa bacteremia, meningitis leading to diffuse cerebritis in an adolescent patient undergoing acute myeloid leukemia chemotherapy causing significant morbidity

Infections with Rothia mucilaginosa are rare. We present an unusual case of Rothia mucilaginosa in an immunocompromised host, which is usually considered a low virulence pathogen. The objective of this report is to highlight spectrum of clinical presentations in an immunocompromised individual and discuss various antimicrobial treatment options in the light of lack of definitive treatment guidelines for this organism.

Rothia mucilaginosa Meningitis in a Child with Myelodysplastic Syndromes

Rothia mucilaginosa is a Gram-positive coccus and an opportunistic pathogen in immunocompromised hosts. The microorganism has been implicated in serious infections, including bacteremia meningitis or endocarditis. However, there is a dearth of investigations on meningitis, especially in children. As this infection is rare and only a few cases have been recorded, evidence-based guidelines for adequate infection treatment are lacking. We herein report the case of a 12-year-old boy with myelodysplastic syndromes (MDS) presenting with a change in mental status who was diagnosed as having febrile neutropenia and bacterial meningitis caused by R. mucilaginosa at 23 days after unrelated cord blood transplant. In our case, the minimum inhibitory concentrations (MICs) of meropenem and vancomycin (VCM) were both ≤1 μg/mL, whereas the MIC of daptomycin (DAP) was 4 μg/mL. The patient was treated with intravenous antimicrobial therapy due to meropenem for 43 days because he had febrile neutropenia. During follow-up, the patient had no neurological complications. We retrospectively reviewed the antimicrobial susceptibility of all R. mucilaginosa isolates (n = 5) from blood or cerebrospinal fluid cultures at our hospital. The MIC of VCM was <0.5 μg/mL for all strains, whereas the MIC of DAP was ≥2 μg/mL for all strains. The MIC of MEPM was >1 μg/mL for one strain. We recommend choosing VCM as the primary treatment for invasive R. mucilaginosa infections until antimicrobial susceptibility results are known, especially in immunocompromised children.

Characterization of the Rothia spp. and their role in human clinical infections

The genus Rothia are emerging as opportunistic pathogens associated with various infections in immunocompromised and immunocompetent individuals. This review describes the taxonomy, cell wall structure, pathogenesis, phenotypic and molecular characteristics, clinical diseases, treatment and, as well as, the related genera that may be misidentified by Rothia species.

Early high dose corticosteroid therapy in hematopoietic stem cell transplantation patients with acute respiratory distress syndrome: a propensity score matched study

BACKGROUND

Acute respiratory distress syndrome (ARDS) is one of the pulmonary complications after hematopoietic cell transplantation (HSCT) with a poor prognosis. The effects of corticosteroid therapy in HSCT patients with ARDS have never been described. In this study, we aim to evaluate the effect of corticosteroid on hospital mortality and other outcomes in patients with HSCT and ARDS.

METHODS

In this bicenter retrospective study, data were collected from patients diagnosed with ARDS and HSCT. Patients were divided into an early high dose steroids group (receiving a cumulative dose ⩾480 mg of methylprednisolone or its equivalent within the first 3 days after ARDS onset) and a no early high dose steroids group. Univariate and multivariate analyses were used to determine the risk factors of hospital mortality. Cox regression was performed to assess the effect of early high dose steroids on patient survival. A propensity score matched cohort was built to validate the results from the original study cohort.

RESULTS

Two hundred and sixty-four patients were included in the original study cohort; 89 (33.71%) patients received early high dose steroids; these patients had higher ventilator free days at day 28 (7.68 ± 4.32 versus 6.48 ± 4.76, p = 0.046); there was no difference in hospital mortality (64.04% versus 53.14%, p = 0.091). Patients with early high dose steroids had a higher incidence of new onset bacteremia (17.98% versus 4%, p < 0.001) and viremia (13.48% versus 3.43%, p = 0.002). The results were further confirmed in the propensity score matched cohort, except for the improvement of ventilator free days (6.02 ± 5.51 versus 5.57 ± 5.54, p = 0.643).

CONCLUSION

In this cohort of HSCT patients with ARDS, early high dose coticosteroids had no effect on hospital mortality. In addition, the incidences of new onset bacteremia and viremia were increased after early high dose steroids.The reviews of this paper are available via the supplemental material section.

Temporal association between human upper respiratory and gut bacterial microbiomes during the course of COVID-19 in adults

SARS-CoV-2 is the cause of COVID-19. It infects multiple organs including the respiratory tract and gut. Dynamic changes of regional microbiomes in infected adults are largely unknown. Here, we performed longitudinal analyses of throat and anal swabs from 35 COVID-19 and 19 healthy adult controls, as well as 10 non-COVID-19 patients with other diseases, by 16 S rRNA gene sequencing. The results showed a partitioning of the patients into 3-4 categories based on microbial community types (I-IV) in both sites. The bacterial diversity was lower in COVID-19 patients than healthy controls and decreased gradually from community type I to III/IV. Although the dynamic change of microbiome was complex during COVID-19, a synchronous restoration of both the upper respiratory and gut microbiomes from early dysbiosis towards late more diverse status was observed in 6/8 mild COVID-19 adult patients. These findings reveal previously unknown interactions between upper respiratory and gut microbiomes during COVID-19.

Rong Xu, Renfei Lu, Tao Zhang, Qunfu Wu, and colleagues perform a longitudinal analysis of throat and gut microbiomes on adult COVID-19 patients. They find initially lower bacterial diversity in COVID-19 patients, but demonstrate a restoration of microbiome diversity throughout disease progression for patients with mild forms of the disease.

Intestinal permeability, microbial translocation, changes in duodenal and fecal microbiota, and their associations with alcoholic liver disease progression in humans

BACKGROUND

Animal data suggest a role of the gut-liver axis in progression of alcoholic liver disease (ALD), but human data are scarce especially for early disease stages.

METHODS

We included patients with alcohol use disorder (AUD) who follow a rehabilitation program and matched healthy controls. We determined intestinal epithelial and vascular permeability (IP) (using urinary excretion of ⁵¹Cr-EDTA, fecal albumin content, and immunohistochemistry in distal duodenal biopsies), epithelial damage (histology, serum iFABP, and intestinal gene expression), and microbial translocation (Gram - and Gram + serum markers by ELISA). Duodenal mucosa-associated microbiota and fecal microbiota were analyzed by 16 S rRNA sequencing. ALD was staged by Fibroscan® (liver stiffness, controlled attenuation parameter) in combination with serum AST, ALT, and CK18-M65.

RESULTS

Only a subset of AUD patients had increased ⁵¹Cr-EDTA and fecal albumin together with disrupted tight junctions and vasculature expression of plasmalemma Vesicle-Associated Protein-1. The so-defined increased intestinal permeability was not related to changes of the duodenal microbiota or alterations of the intestinal epithelium but associated with compositional changes of the fecal microbiota. Leaky gut alone did not explain increased microbial translocation in AUD patients. By contrast, duodenal dysbiosis with a dominance shift toward specific potential pathogenic bacteria genera (Streptococcus, Shuttleworthia, Rothia), increased IP and elevated markers of microbial translocation characterized AUD patients with progressive ALD (steato-hepatitis, steato-fibrosis).

CONCLUSION

Progressive ALD already at early disease stages is associated with duodenal mucosa-associated dysbiosis and elevated microbial translocation. Surprisingly, such modifications were not linked with increased IP. Rather, increased IP appears related to fecal microbiota dysbiosis.

Evaluation of microbial contamination of different pork carcass areas through culture-dependent and independent methods in small-scale slaughterhouses

Routine evaluation of the slaughter process is performed by the enumeration of the aerobic colony count, Enterobacteriaceae and Salmonella spp. on the carcass through destructive or non-destructive methods. With non-destructive methods, bacteria are counted from a minimum area of 100 cm² in different sampling sites on the pork carcasses, and the results of these investigated areas are pooled to one value for the complete carcass evaluation (a total of 400 cm²). However, the composition of the bacterial community present on the different sampling areas remains unknown. The aim of the study was to characterize the microbial population present on four areas (ham, back, jowl and belly) of eight pork carcasses belonging to two different slaughterhouses through culture-dependent (Matrix-assisted laser desorption/ionization time-of-flight Mass Spectrometry MALDI-TOF MS, combined with 16S rRNA gene sequencing) and complementary culture-independent (16S rRNA amplicon sequencing) methods. The presence of Salmonella spp. and Y. enterocolitica was additionally assessed. Using MALDI-TOF MS, Staphylococcus, Pseudomonas, and Escherichia coli were found to dominate the bacterial cultures isolated from the 8 carcasses. Based on the 16S rRNA amplicon sequencing analyses however, no specific genus clearly dominated the bacterial community composition. By using this culture-independent method, the most abundant genera in microbial populations of the ham, back, jowl and belly were found to be similar, but important differences between the two slaughterhouses were observed. Thus, present data suggests that the indigenous bacterial population of individual animals is overruled by the microbial population of the slaughterhouse in which the carcass is handled. Also, our data suggests that sampling of only one carcass area by official authorities may be appropriate for the evaluation of the hygienic status of the carcasses and therefore of the slaughter process.

Quantification and interpretation of attributable mortality in core clinical infectious disease journals

Attributable mortality is an important metric that mirrors the public health effect of a potentially harmful infection by accounting not only for the effect of infection on mortality, but also for its prevalence within the target population. We did a systematic literature review to identify how attributable deaths were quantified and interpreted in core clinical infectious diseases journals between Jan 1, 2013, and April 6, 2020. Of the 1591 abstracts screened, 234 entered the primary analysis. Our summary of the epidemiological measures used in these articles reveals fundamental shortcomings in the conception of attributable mortality. Because of its importance as a basis for decision making on public health matters, it is essential to correctly quantify and report on attributable mortality. Our recommendation for quantification and reporting of attributable deaths aids clinical researchers in the correct statistical assessment of the burden of infections. Fictional as well as real data is used to illustrate these issues.

Levofloxacin versus Cefpodoxime for Antibacterial Prophylaxis in Allogeneic Stem Cell Transplantation

National guidelines recommend antimicrobial prophylaxis for allogeneic stem cell transplant patients during the pre-engraftment period because of increased infection risk during neutropenia. Fluoroquinolones have demonstrated lower rates of bacteremias and incidence of neutropenic fever, but there is limited evidence in the use of alternative antibacterials such as cefpodoxime. The primary objective of this study is to compare the rates of antibiotic prophylaxis failure between levofloxacin and cefpodoxime in allogeneic stem cell transplant recipients. Secondary objectives include comparing and characterizing number and type of infections, mortality at day 100 post-transplant, and hospitalizations for infectious causes in the first 100 days of transplant. This is a single-center, retrospective chart review of adult patients who received an allogeneic stem cell transplant from matched related and matched unrelated donors and antibacterial prophylaxis with levofloxacin or cefpodoxime from January 1, 2011, to October 1, 2014. A total of 142 patients were evaluated (71 levofloxacin, 71 cefpodoxime). Both levofloxacin and cefpodoxime groups had similar rates of neutropenic fever and antibiotic prophylaxis failure (58% versus 58%, P = NS). There were similar incidences of Clostridioides difficile and Multi-drug resistant (MDR) infections among both levofloxacin and cefpodoxime groups. Rates of infections, hospitalizations, and mortality in the first 100 days were similar among both groups. Cefpodoxime can be used as an alternative to levofloxacin for antibiotic prophylaxis in allogeneic stem cell transplant patients.

Rothia mucilaginosa bacteremia: A 10-year experience of a pediatric tertiary care cancer center

Rothia mucilaginosa is part of the oral and upper respiratory tract flora. Usually, this gram-positive coccus is not pathogenic; however, in the setting of immunosuppressed hosts, it can cause life-threatening infections as an opportunistic pathogen. Among a cohort of 1511 hematologic-oncologic patients at a pediatric tertiary care cancer center, we identified five cancer patients (0.35%) within a period of 10 years having a proven Rothia mucilaginosa bacteremia (1 culture positive: n = 3/5; > 1 culture positive: n = 2/5). With prompt and adequate antibiotic treatment, infection resolved rapidly before recovery of neutrophils and without any sequelae, suggesting that Rothia mucilaginosa bacteremia without organ involvement is not exceptionally problematic in pediatric cancer patients.

Meningitis in a patient with neutropenia due to Rothia mucilaginosa: a case report

BACKGROUND

Rothia mucilaginosa is a Gram-positive bacterium occurring as a commensal in the oral cavity and upper respiratory tract. Although rarely pathogenic in an immunocompetent host, it can cause severe opportunistic infections in immunocompromised individuals.

CASE PRESENTATION

A 67-year-old white woman had a routine blood analysis before undergoing knee surgery. The results showed leukopenia for which bone marrow examination was performed, showing an underlying acute myeloid leukemia. During the neutropenic phase after a second induction with cytarabine/idarubicin, she developed fever, headaches, and photophobia. Cultures of cerebrospinal fluid were positive for Rothia mucilaginosa. Despite full therapy with antibiotics, neurosurgical interventions, and intensive care support, our patient died due to refractory intracranial hypertension and transtentorial herniation.

CONCLUSIONS

Meningitis due to Rothia mucilaginosa is a rare but potentially lethal infection in patients with neutropenia, and evidence-based guidelines for the treatment of this disease are lacking. We suggest an empirical therapy with amoxicillin/rifampicin until adjustments can be made based on an antibiogram. Intrathecal or intraventricular administration of antibiotics can be considered if neurosurgical access is already obtained because of disease-associated complications.

Transcriptional Profiling of C. albicans in a Two Species Biofilm with Rothia dentocariosa

Biofilms on silicone rubber voice prostheses are the major cause for frequent failure and replacement of these devices. The presence of both bacterial and yeast strains has been suggested to be crucial for the development of voice prosthetic biofilms. Polymicrobial biofilms that include Candida albicans and Rothia dentocariosa are the leading cause of voice prosthesis failure. An in vitro biofilm comprising these two organisms was developed on silicone rubber, a material used for Groningen button voice prosthesis. We found that this biofilm environment was not conducive for C. albicans growth or differentiation. Global transcriptional analyses of C. albicans biofilm cells grown with R. dentocariosa revealed that genes with functions related to cell cycle progression and hyphal development were repressed >2-fold. The mixed species biofilms were more compact and less robust compared to C. albicans mono-species biofilms, even when developed under conditions of continuous nutrient flow. Under these conditions R. dentocariosa also significantly inhibited C. albicans biofilm dispersal. Preferential adherence of R. dentocariosa to candidal hyphae was mediated by the adhesin Als3.

Identification of Emerging Human Mastitis Pathogens by MALDI-TOF and Assessment of Their Antibiotic Resistance Patterns

Lactational mastitis constitutes one of the main causes of undesired weaning, depriving the mother–infant pair from the benefits of breastfeeding; therefore, this condition should be considered a relevant public health issue. The role of specific microorganisms remains unclear since human milk cultures and antibiotic susceptibility testing (AST) are not routinely performed, despite the fact that this would be key to ensure an early and effective diagnosis and treatment. The objective of this study was to describe the culturable microbial diversity in 647 milk samples from breastfeeding women with clinical symptoms of mastitis by Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF) VITEK MS technology and to analyze the antimicrobial susceptibility profiles of a collection of isolates from these samples by the VITEK 2 AST system. Staphylococcus epidermidis was the most common species isolated from mastitis samples (87.6%), while Staphylococcus aureus was detected in 22.1%. Streptococci constituted the second (68.6%) most prevalent bacterial group, with Streptococcus mitis/oralis, Streptococcus salivarius, and Streptococcus parasanguinis detected with frequencies of 40.8, 36.8, and 14.4%, respectively. The antibiotic susceptibility profiles of 642 staphylococcal isolates indicated a remarkable resistance to benzylpenicillin (88.3%) and erythromycin (67.3%) with differences between species. A high percentage of Staphylococcus isolates were resistant to at least one antibiotic (Staphylococcus hominis, 100%; S. epidermidis, 98.2%; S. aureus, 92.9%; Staphylococcus lugdunensis, 90.5%) and the percentage of multidrug-resistance (MDR) isolates was noticeable (S. hominis, 81%; S. epidermidis, 64.4%; S. aureus, 11.5%; S. lugdunensis, 10.5%). In relation to streptococcal isolates (n = 524), AST revealed high or moderate percentages of resistance to erythromycin (68.7%), benzylpenicillin (63.7%), ampicillin (51.5%), and tetracycline (30.8%). Antibiotic resistance to at least one antibiotic was detected in 97.6% of S. parasanguinis, 92.6% of S. salivarius, 83.3% of S. mitis/oralis, and 72.4% of Streptococcus vestibularis isolates. A significant number of MDR streptococcal isolates was also found (S. parasanguinis, 51.2%; S. salivarius, 39.3%; S. mitis/oralis, 34.6%; and S. vestibularis, 19%). The results highlight the important role of coagulase-negative staphylococci and streptococci as human mastitis-causing agents. Moreover, the high rates of antimicrobial resistance among these microorganisms must be contemplated as an issue of clinical relevance in relation to treatment options.