Defining the microbiome of the head and neck: A contemporary review.

OBJECTIVE: The purpose of this paper is to define the microbiome of the head and neck by characterizing and distinguishing the commensal bacteria from pathogenic species. STUDY DESIGN: Literature review. METHODS: Pubmed and Google scholar databases were queried for relevant articles. Keywords such as "middle ear microbiome", "outer ear microbiome", "sinonasal microbiome", "tonsil microbiome", and "laryngeal microbiome" were utilized separately to identify articles pertaining to each topic of study. All applicable abstracts were chosen for initial review and relevant abstracts were then selected for review of the full texts. Articles that did not study the human microbiome, those not written primarily in English, those that were not readily available for full review, and case reports were excluded from the study. RESULTS: Limited studies that investigate the microbial environments of isolated anatomic subsites in the head and neck exist, however the comprehensive microbiome of the head and neck has yet to be completely defined. Based on this review, various studies of the ears, larynx, tonsils and sinus microbiomes exist and yield valuable information, however they are limited in scope and anatomic subsite. In this literature review, these studies are compiled in order to create a comprehensive text inclusive of the known microbial elements of the major anatomic subsites of the head and neck, namely the tonsils, larynx, sinus, outer ear and middle ear. CONCLUSIONS: The significance of the human microbiome in identifying and preventing disease has been established in various physiologic systems, however there is limited research on the microbiome of the head and neck. Understanding the microbiome of the head and neck can help differentiate disease-prone patients from normal patients and guide treatment regimens and antibiotic usage, to aid in resistance control and limit adverse effects of antibiotic overuse. Understanding the elements that lead to dysbiosis can help treat and even prevent common conditions as tonsillitis and rhinosinusitis. In this review, we provide a comprehensive review to serve as an initial background for future studies to define the head and neck microbiome distinguished by all relevant subsites.

Regulation of axial and head patterning during planarian regeneration by a commensal bacterium.

Some animals, such as planaria, can regenerate complex anatomical structures in a process regulated by genetic and biophysical factors, but additional external inputs into regeneration remain to be uncovered. Microbial communities inhabiting metazoan organisms are important for metabolic, immune, and disease processes, but their instructive influence over host structures remains largely unexplored. Here, we show that Aquitalea sp. FJL05, an endogenous commensal bacterium of Dugesia japonica planarians, and one of the small molecules it produces, indole, can influence axial and head patterning during regeneration, leading to regeneration of permanently two-headed animals. Testing the impact of indole on planaria tissues via RNA sequencing, we find that indole alters the regenerative outcomes in planarians through changes in expression to patterning genes, including a downregulation of Wnt pathway genes. These data provide a unique example of the product of a commensal bacterium modulating transcription of patterning genes to affect the host's anatomical structure during regeneration.

Complicated Head and Neck Infections Following Influenza Virus Infection in Children.

Seasonal influenza infection is associated with secondary bacterial complications involving the upper and lower respiratory tract. However, the association of influenza infection with secondary severe or complicated head and neck infections is not appreciated. We report 6 cases of head and neck infections following influenza infection in pediatric patients.

The role of immediate versus secondary removal of the odontogenic focus in treatment of deep head and neck space infections. A retrospective analysis of 248 patients.

OBJECTIVES: Aim of this study was to investigate conditions and predisposing factors for head and neck infection progress regarding the length of stay (LOS) in hospital, with special emphasis on the time of removal of the odontogenic infection focus. MATERIAL AND METHODS: A 3-year retrospective study reviewed hospital records of 248 subjects who were treated under inpatient conditions with severe odontogenic infections who received surgical incisions, drainage, and intravenous (IV) antibiotics. Outcomes measured included age, gender, involved fascial spaces, LOS, number of infected spaces, antibiotics administered, and comorbidities. We precisely recorded the time between abscess incision and focus extraction. RESULTS: Removal of infection focus (tooth) in the same stay (1 stay, n = 106; group 1; mean 6.5 days ± 3) showed significantly higher (p = 0.042) LOS than extraction in a second stay (2 stays, n = 46; group 2; 5.3 ± 3.1). Group 3 patients showed infection after removal of teeth in outpatient management (1 stay ex-op, n = 96) and presented significantly lower LOS (5.6 ± 2.5) compared to group 1 (p = 0.0216). LOS of group 3 to group 2 patients showed no significance (p = 0.668). Infection expansion and diabetes showed a significant increase of LOS. CONCLUSION: Simultaneous removal of infection focus and abscess incision leads to the lowest LOS. If tooth extraction is performed after incision, subsequent focus extraction performed in a second stay shows lower overall-LOS than extraction at the same stay at later stage. CLINICAL RELEVANCE: Multiple factors tend to increase the LOS of patients with severe head and neck infections of odontogenic origin. Our data reveals the role of removal of odontogenic focus and additionally ranks further parameters that influence the LOS. Based on our findings, decisions regarding the surgical treatment can be recommended.

Sustainable recovery of protein-rich liquor from shrimp farming waste by lactic acid fermentation for application in tilapia feed.

The biotransformation of shrimp head waste into ingredients for Nile tilapia (Oreochromis niloticus) post-larvae (PLs) diet formulations was evaluated herein. A novel consortium of lactic acid bacteria, comprising the strains Lactobacillus futsaii LAB06 and L. plantarum LAB14, selected based on kinetic growth parameters, was applied in the fermentation of shrimp head waste. After 48 h, the highest lactic acid production was 100 g L-1, allowing for maximum recovery of chitin and protein-rich liquor. The liquor was added to commercial powdered fish feed at 15, 30, and 45% (w/w) and offered to Nile tilapia PL during 28 days. The inclusion of 30% provided the best results for Nile tilapia PL survival, weight and length gains, specific growth rate, and biomass, proving that the fermented liquor can be incorporated, leading to economic benefits and contributing to the reduction of environmental pollution caused by the improper disposal of shrimp waste.

Understanding the microbial basis of body odor in pre-pubescent children and teenagers.

BACKGROUND: Even though human sweat is odorless, bacterial growth and decomposition of specific odor precursors in it is believed to give rise to body odor in humans. While mechanisms of odor generation have been widely studied in adults, little is known for teenagers and pre-pubescent children who have distinct sweat composition from immature apocrine and sebaceous glands, but are arguably more susceptible to the social and psychological impact of malodor. RESULTS: We integrated information from whole microbiome analysis of multiple skin sites (underarm, neck, and head) and multiple time points (1 h and 8 h after bath), analyzing 180 samples in total to perform the largest metagenome-wide association study to date on malodor. Significant positive correlations were observed between odor intensity and the relative abundance of Staphylococcus hominis, Staphylococcus epidermidis, and Cutibacterium avidum, as well as negative correlation with Acinetobacter schindleri and Cutibacterium species. Metabolic pathway analysis highlighted the association of isovaleric and acetic acid production (sour odor) from enriched S. epidermidis (teen underarm) and S. hominis (child neck) enzymes and sulfur production from Staphylococcus species (teen underarm) with odor intensity, in good agreement with observed odor characteristics in pre-pubescent children and teenagers. Experiments with cultures on human and artificial sweat confirmed the ability of S. hominis and S. epidermidis to independently produce malodor with distinct odor characteristics. CONCLUSIONS: These results showcase the power of skin metagenomics to study host-microbial co-metabolic interactions, identifying distinct pathways for odor generation from sweat in pre-pubescent children and teenagers and highlighting key enzymatic targets for intervention.

Histoplasmosis of the head and neck in the immunocompetent patient: Report of 2 cases.

Histoplasmosis of the head and neck is rarely seen in immunocompetent patients. We report 2 new cases of histoplasmosis of the head and neck in immunocompetent patients, one an 80-year-old man and the other a 57-year-old man. The older man presented with oral cavity histoplasmosis; his symptoms included pain, dysphagia, and ulcerative lesions. The younger man had laryngeal histoplasmosis, which resulted in hoarseness and dyspnea. We discuss the methods of diagnosis and the classic findings in histoplasmosis, including the microscopic appearance of caseating granulomas, the results of periodic acid-Schiff staining and Gomori staining, and antibody detection of histoplasmosis. We also review the treatment options with antifungals, including amphotericin B and the oral conazole drugs. With an accurate diagnosis and proper treatment, both of our patients recovered well and their symptoms resolved. Because their symptoms overlapped with those of other, more common disease processes, an accurate diagnosis of these patients was essential to treating their infection.

Urgent Infections of the Head and Neck.

Infections of the head and neck are common and appropriately managed by primary care providers in most cases. However, some infections are associated with significant morbidity and require urgent recognition and management by specialty services. These include deep neck space infections originating in the oral cavity, pharynx, and salivary glands, as well as complicated otologic and sinonasal infection. This article provides a review of these conditions, including the pathophysiology, presenting features, and initial management strategy.

Clinical presentation and treatment of melioidosis in the head and neck region.

BACKGROUND: Although melioidosis in the head and neck region is uncommon, it is a potentially life-threatening infection. Thus, early diagnosis and proper management are very important. OBJECTIVES: To report the clinical presentation and management of melioidosis in the head and neck. METHOD: A retrospective study was conducted from 1 January 2013 to 31 October 2016 in Mukdahan Hospital, Thailand. Case records of patients who had presented with culture-positive melioidosis were analysed. RESULTS: Medical records of 49 patients (23 males and 26 females) were analysed. Patients ranged in age from 1 to 75 years. Clinical presentations included 22 parotid abscesses, 16 neck abscesses and 11 suppurative lymphadenitis cases. Only 35 patients (71 per cent) had high indirect haemagglutination assay titres of ≥ 1:160 (95 per cent confidence interval = 45.35-88.28). Almost half of the patients received intravenous ceftazidime and subsequently oral co-trimoxazole. Oral antibiotic regimens were prescribed for mild localised melioidosis. Overall, 95.65 per cent of patients were in remission and no relapses were observed (95 per cent confidence interval = 85.47-98.80). CONCLUSION: Careful clinical correlation and proper investigation are required to establish an early diagnosis of melioidosis and to initiate appropriate treatment.

Tuberculosis: the great imitator in the head and neck - our experience of 24 cases in 22 years.

This retrospective study covered over two decades, during which an individual head and neck surgeon treated 24 patients with cervicofacial lymphadenitis that was related to both Mycobacterium tuberculosis complex (n=17, made up of M tuberculosis (n=16) and M bovis (n=1)), and non-tuberculous mycobacteria. The seven cases of non-tuberculous mycobacteria were caused by M avium complex (n=3), M malmoense (n=3), and M kansaii (n=1). By using a tailored management approach, at times selective combined surgical and antimycobacterial treatment, he achieved a success rate of 23/24 cases, with only one recurrence and no major complications. The results suggest that patients with tuberculosis confined to the head and neck rarely develop constitutional symptoms, so the absence of such symptoms may not exclude tuberculosis. There was also a good correlation between predictive variables (immune state, inflammatory markers on admission, causative mycobacterium, and the antimycobacterial regimen used) and time spent under follow-up at the head and neck outpatient clinic.

Clinical study of tuberculosis in the head and neck region-11 years' experience and a review of the literature.

Tuberculosis (TB) is an infectious disease and major health concern. Head and neck tuberculosis (HNTB) is relatively rare, but can arise in many regions, including the lymph nodes, larynx, oral cavity and pharynx. We retrospectively reviewed the clinical records of 60 patients diagnosed with HNTB in our department between March 2005 and January 2016. A review and summary of previous HNTB articles published in PubMed since 1885 was also performed. The subjects consisted of 17 males and 43 females, and the average age of patients was 45 ± 14.67 years. The major clinical presentation was a lump or swelling, followed by an oral ulcer and skin fistula. The most common site of tuberculosis was in the cervical lymph node. Three patients also suffered from a malignant tumor in the head and neck region. A total of 980 papers involving 5881 patients were included in our literature review. The included subjects ranged in age from 15 months to 100 years with a male-to-female ratio of 1.5:1. The larynx (38.92%), cervical lymph nodes (38.28%) and oral cavity (9.92%) were the three most common development sites. 465 patients were positive according to a HIV test, and 40 patients had comorbidities with different types of tumors. Head and neck tuberculosis should always be considered during a differential diagnosis for lesions in the head and neck region. Early diagnosis and treatment can greatly enhance the therapeutic effect and patients' quality of life.

Streptomyces lasii sp. nov., a Novel Actinomycete with Antifungal Activity Isolated from the Head of an Ant (Lasius flavus).

During a screening for novel and biotechnologically useful actinobacteria in insects, a novel actinobacteria with antifungal activity, designated strain 5H-CA11T, was isolated from the head of an ant (Lasius flavus) and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of members of the genus Streptomyces. 16S rRNA gene sequence analysis showed that strain 5H-CA11T is a member of the genus Streptomyces, with the highest sequence similarity to Streptomyces scabrisporus DSM 41855T (98.9%). Similarities to other type strains of the genus Streptomyces were lower than 96%. Phylogenetic analysis based on the 16S rRNA gene sequence also indicated that strain 5H-CA11T clusters with S. scabrisporus DSM 41855T using two tree-making algorithms. DNA-DNA hybridization between strain 5H-CA11T and S. scabrisporus JCM 11712T revealed 33.6% similarity, supporting the phenotypic and phylogenetic differences found between these two strains. Therefore, the strain is concluded to represent a novel species of the genus Streptomyces, for which the name Streptomyces lasii sp. nov. is proposed. The type strain is 5H-CA11T (=CGMCC 4.7303T = DSM 102043T).

Sepsis + ptosis = an unusual diagnosis.

The authors present the case of a 19-year old man presenting to the emergency department with a 2-day history of left eye pain and ptosis, facial pain around the maxillae, coryza, headaches and fevers. He had a background of autism, mild learning disability, obsessive-compulsive disorder and asthma. Within the last month, his risperidone and sertraline doses had been increased. Basic observations and investigations suggested sepsis: tachypnoea, sinus tachycardia, fever and a raised white cell count and C reactive protein level. A CT head showed sinonasal polyposis and moderate chronic rhinosinusitis, with normal intracranial appearances. An MRI head showed evidence of extension of frontal sinus infection through the posterior wall of the left frontal sinus with subsequent left frontal extradural empyema. Intravenous antibiotics and surgical drainage of the left frontal sinus resulted in clinical improvement and discharge to complete the course of antibiotics in the community.

Surgical Head Coverings: A Literature Review.

Microorganisms that cause surgical site infections may either be present on the patient's skin or mucous membranes or transmitted to the patient by health care personnel, the environment, or other items in the perioperative setting. This literature review analyzes the evidence used to support the recommendation that perioperative personnel should cover their heads, hair, and ears in the semirestricted and restricted areas. A literature search produced 27 articles related to bacterial shedding from skin and hair, pathogenic organisms present on the hair and ears, and case reports of infectious organisms passed from health care providers to patients. Although there is no conclusive evidence that wearing a head covering can help prevent surgical site infections, the potential benefits to patients when compared with the risks suggest that perioperative team members should cover their heads, hair, and ears in the semirestricted and restricted areas to provide the best possible protection for surgical patients.

Efficacy of Intralipid infusion in reducing amphotericin-B-associated nephrotoxicity in head and neck invasive fungal infection: A randomized, controlled trial.

Amphotericin B deoxycholate (ABD) is the best therapeutic agent available for the treatment of most systemic fungal infections. However, some untoward adverse effects such as nephrotoxicity may limit its appropriate therapeutic use. We conducted a randomized, controlled trial ofthe infusion of fat emulsion (Intralipid) shortly after the infusion of ABD to evaluate its effects on reducing ABD-associated nephrotoxicity. Our patient population was made up of 31 patients who were randomized into two groups: an intervention group (n = 16) and a control group (15 patients). There were no statistically significant differences between the two groups in demographic or clinical variables. All patients received 1mg/kg/day of ABD in dextrose 5%. In addition, the patients in the intervention arm received Intralipid 10%, which was started as soon as possible within 1 hour after the infusion of ABD. ABD-associated nephrotoxicity was defined as a minimum 50% increase in baseline serum creatinine to a minimum of 2mg/dl. We also measured daily serum creatinine changes during the first 2 weeks of treatment, and we compared some other relevant indices of renal function, as well as ABD-related hypokalemia. We found no statistically significant differences between the two treatments in terms of ABD-associated nephrotoxicity or any of the other indices. We conclude that the administration of Intralipid 10% early after infusion of ABD in dextrose 5% does not have any effect in decreasing ABD-associated nephrotoxicity or hypokalemia.

Impact of Pneumococcal Conjugate Vaccines on Selected Head and Neck Infections in Hospitalized Israeli Children.

BACKGROUND: Streptococcus pneumoniae is a major pathogen of pediatric head and neck infections (HNIs), for example, acute otitis media (AOM), acute mastoiditis, acute bacterial sinusitis and meningitis. The aim of this study was to characterize the epidemiology of pneumococcal HNIs (pHNIs) before, during and after the introduction of pneumococcal conjugate vaccines (PCVs). METHODS: Children 0-16 years of age, who were hospitalized with HNIs in the pediatrics department in a general hospital between January 1, 2007, and December 31, 2014, were retrospectively identified. Study years were categorized according to the PCV introduction timeline: 2007-2008: "pre-PCV years"; 2009-2011: "transition years" and 2012-2014: "post-PCV years." pHNIs episodes were defined if pneumococcal culture or urine antigen was positive. Children who received ≥2 doses of PCV7/PCV13 were considered as immunized. All other children were considered as unimmunized. RESULTS: HNIs accounted for 2.5%-4.7% of the total admissions; 3%-17% of them were pHNIs. Eighty-seven pHNI episodes were identified: AOM (n = 42), acute mastoiditis (n = 28) and meningitis (n = 17). There was a downward trend in the overall incidence of HNIs, and particularly of pHNIs, in the post-PCV years. The average age and hospitalization duration of children with HNIs/pHNIs remained stable during the study years. In 2009-2010, pHNIs incidence sharply decreased, from 7 to 1.74/1000 hospitalized children/year, due to ~55% reduction of pneumococcal AOM episodes. An additional decrease was observed in the post-PCV years (1.62/1000 hospitalized children/year). Immunized children were less likely to present with pHNIs (P = 0.001) but were more likely to undergo surgery (P = 0.042). CONCLUSION: We observed a reduction in pHNIs incidence after PCV program implementation.

Magnetic Resonance Imaging of Acute Head and Neck Infections.

This article discusses the use of MR imaging in various acute infectious diseases of the head and neck, with particular emphasis on situations where MR imaging provides additional information that can significantly impact treatment decisions and outcomes. MR imaging findings of various disease processes are discussed, based on the head and neck compartments from which they originate. Specifically, infectious entities of the orbit, paranasal sinuses, pharynx, oral cavity (including periodontal disease), salivary glands, temporal bone, and lymph nodes are described in detail.

Risk Factors for Life-Threatening Complications of Maxillofacial Space Infection.

The purpose of this study was to review the clinical features of maxillofacial space infection (MSI), and to identify the potential risk factors predisposing to life-threatening complications. A retrospective review of the medical charts of patients with MSI treated at Peking University School and Hospital of Stomatology from August 2008 to September 2013 was conducted. A total of 127 patients [75 men (59.1%) and 52 women (40.9%); mean age, 45.39 ± 21.18 years, with a range of 1-85 years] formed the study cohort. The most common cause of MSI was odontogenic infection (57.5%). The most common space involved was the submandibular space. All patients were treated by antibiotics as well as surgical incision and drainage. Sixteen patients developed life-threatening complications, and the dominant complication was respiratory obstruction. Multivariate logistic regression analysis revealed the percentage of neutrophils (NEUT%) upon hospital admission ≥ 85.0% to be associated with life-threatening complications (P < 0.05). Even though adequate antibiotic therapy and incision and drainage of abscess were given, MSI patients with NEUT% upon hospital admission ≥ 85.0% carry a higher risk of life-threatening complications. In these patients, an aggressive treatment strategy is mandatory.