Role of methicillin-resistant Staphylococcus aureus in head and neck infections

High risk and low prevalence diseases: Acute mastoiditis

INTRODUCTION

Acute mastoiditis is a serious condition that carries with it a high rate of morbidity and mortality.

OBJECTIVE

This review highlights the pearls and pitfalls of mastoiditis, including the presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Acute mastoiditis most commonly affects pediatric patients and is a suppurative infection of the mastoid air cells. It is often associated with otitis media, and common bacteria include Streptococcus and Staphylococcus. History and examination may reveal tympanic membrane erythema, pinna protrusion, postauricular erythema, mastoid tenderness with palpation, external canal swelling, otorrhea, fever, and malaise. The disease should be suspected in those who fail treatment for otitis media and those who demonstrate the aforementioned abnormalities on examination and systemic symptoms. Laboratory analysis may reveal evidence of systemic inflammation, but a normal white blood cell count and other inflammatory markers should not be used to exclude the diagnosis. Computed tomography (CT) of the temporal bones with intravenous contrast is the recommended imaging modality if the clinician is unsure of the diagnosis. CT may also demonstrate complications. Treatment includes antibiotics such as ampicillin-sulbactam or ceftriaxone as well as otolaryngology consultation. Complications may include subperiosteal and intracranial abscess, deep neck abscess, facial nerve palsy, meningitis/encephalitis, venous sinus thrombosis, and seizures.

CONCLUSIONS

An understanding of acute mastoiditis can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

Detection of Oxacillin/Cefoxitin Resistance in Staphylococcus aureus Present in Recurrent Tonsillitis

Background: Recurrent tonsillitis is one of the most common diseases in childhood, caused many times by ß-lactam-resistant S. aureus. The objective of this study was to investigate an alternative method to identify resistance to oxacillin/cefoxitin in S. aureus from hospitalized children with recurrent tonsillitis. Methods: The samples of S. aureus came from patients with recurrent tonsillitis and were used in 16S rRNA sequencing and an antibiogram test for identification and verifying resistance, after which HSI methodology were applied for separation of S. aureus resistances. Results: The S. aureus isolated showed sensitivity to oxacillin/cefoxitin and the diagnostic images show a visual description of the resistance different groups formed, that may be related to sensitivity and resistance to oxacillin/cefoxitin, characterizing the MRSA S. aureus. Conclusions: Samples that showed phenotypic resistance to oxacillin/cefoxitin were clearly separated from samples that did not show this resistance. A PLS-DA model predicted the presence of resistance to oxacillin/cefoxitin in S. aureus samples and it was possible to observe the pixels classified as MRSA. The HSI was able to successfully discriminate samples in replicas that were sensitive and resistant, based on the calibration model it received.

Diagnosis and Treatment of Lip Infections

PURPOSE

Staphylococcus aureus is a gram-positive, facultative anaerobic, cocci bacterium that naturally colonizes the skin. S aureus can cause a mild to severe infection depending on the location, depth of invasion, and immune status. Guidelines regarding treatment of patients with lip infections are scant. The purpose of this study was to present the diagnosis, management, and outcome of a cohort of patients with lip infections caused by S aureus.

MATERIALS AND METHODS

This was a retrospective cohort study of patients with a lip infection caused by S aureus treated by Emory Oral and Maxillofacial Surgery Service (Atlanta, GA). Predictor variables were patient demographic characteristics, clinical presentation, laboratory findings, imaging characteristics, intervention, and length of stay. The outcome variable was infection resolution or persistence. Data were collected using a standardized collection form. Descriptive statistics were computed.

RESULTS

Seven patients (mean age, 38 years) with lip swelling met the inclusion criteria. The patients did not undergo recent hospitalization and/or recent surgery. Patients had immunodeficiency virus or other medical comorbidities. Radiographic findings were consistent with abscess formation. Management consisted of antibiotics only or surgical intervention with antibiotics. Lip cultures showed S aureus with methicillin-sensitive or -resistant S aureus. Treatment was intravenous followed by oral antibiotics. The average length of inpatient stay was 4 days. There were no postoperative complications. All lip infections achieved complete clinical resolution.

CONCLUSIONS

In this cohort, treatment of lip swelling caused by S aureus required surgical intervention and/or antibiotics. Immune compromise and antibiotic resistance should be considered in a patient with a similar presentation.

Concurrent Methicillin-Resistant Staphylococcus aureus Septicemia and Thyroid Abscess in a Young Male with Dengue

BACKGROUND

Dengue fever is an arthropod-borne viral infection with a very high incidence rate in Southeast Asia. Most patients present with self-limiting febrile illness, while some patients may develop complications like acute kidney injury, acute liver failure, myocarditis or Guillain- Barre syndrome. The coexistence of Dengue and MRSA (Methicillin-resistant Staphylococcus aureus ) is rarely reported in the literature.

CASE

A 28-year-old male is presented with high-grade fever, polyserositis and thrombocytopenia. The patient was treated symptomatically for dengue infection. During the course of hospitalization, patient developed neck swelling (thyroid abscess) and left forearm abscess. MRSA was isolated from blood culture and pus, and successfully treated with iv antibiotics (Vancomycin).

CONCLUSION

High anticipation and vigilance are required to detect concurrent bacteremia in dengue patients. Early recognition of warning signs with readily antibiotic therapy is important to prevent mortality and morbidity in these patients. Our report also highlights the MRSA as a rare cause of thyroid abscess, with only 5 cases reported in the literature so far.

Confluent Retropharyngeal, Lateral Pharyngeal, and Peritonsilar MRSA Abscess in an Infant

Neck abscesses such as retropharyngeal, peritonsilar, and lateral pharyngeal are well described, typically cause a characteristic illness, and have a known epidemiology. We present a rare occurrence of case of confluent, mixed retropharyngeal, lateral pharyngeal, and peritonsilar abscess in a 9-month-old female infant. The symptoms at presentation were very mild and not expected in association with this extensive an abscess. The causative organism was methicillin-resistant Staphylococcus aureus.

Thyroid Abscess: Challenges in Diagnosis and Management

Thyroid abscess is an uncommon infectious pathology. The thyroid is highly resistant to infection due to high iodine content, capsular encasement, and rich vascularity. Acute suppurative thyroiditis represents <1% of thyroid diseases that could potentially become a life-threatening endocrine emergency. A 48-year-old woman with AIDS presented with 3 days of fever, tender neck swelling, and methicillin-resistant Staphylococcus aureus bacteremia. Apart from leukocytosis, initial laboratory values including thyroid function tests were normal. The initial plain computed tomography scan of the neck and ultrasound scan of the neck were inconclusive as well. By day 4, she worsened, and on repeat computed tomography scan of the neck with contrast, multiloculated abscesses in the thyroid and retro pharynx were seen, which needed emergent drainage. Acute suppurative thyroiditis, a rare disease, occurs in patients with either preexisting disorders of the thyroid or in the immunocompromised. The most common pathogen is Staphylococcus aureus. In our case, we highlight the fact that initial imaging may be negative in the early stages of acute suppurative thyroiditis and lead to an erroneous diagnosis of subacute thyroiditis. There are less than 5 cases of methicillin-resistant Staphylococcus aureus suppurative thyroiditis reported.

Methicillin-resistant Staphylococcus Aureus Lip Infection Mimicking Angioedema

BACKGROUND

It is rare for angioedema to be misidentified by the experienced clinician or for it to mimic another disease process. As an Emergency Physician, it is important to recognize and treat angioedema immediately. Of equal importance is the recognition and initiation of treatment of facial cellulitis. A case report follows that illustrates methicillin-resistant Staphylococcus aureus (MRSA) lip infection mimicking angioedema.

CASE REPORT

Here, we describe a case of a 21-year-old man who presented with a swollen lower lip, initially diagnosed as angioedema. Further investigation revealed the cause of his lip swelling was actually a MRSA abscess and surrounding cellulitis, an unusual presentation for lip infection, which we discuss below. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Misidentifying MRSA lip infection for angioedema, with a delay in proper treatment, could result in serious morbidity or mortality.

[Chronic tonsillitis, etiological and pathogenetic aspects of the development of metatonsillar complications]

The objective of the present study was to summarize the data of the current literature publications concerning the tonsillar biotope under the normal conditions and in the course of the development of the pathological process. Specific microbiological characteristics of the potential causative agents of tonsillar pathology are considered. The structural, immunological, and genetic prerequisites for the for progress of infection are discussed with special reference to the morphological and functional changes in the tissue of palatine tonsils associated with different forms of the disease and the mechanisms underlying immunopathological conditions and metatonsillar complications.

Pediatric deep space neck infections in U.S. children, 2000-2009

OBJECTIVE

Deep space neck infections (DNI) are common pediatric illnesses, which can lead to significant morbidity and healthcare expenditures. Recent studies suggest that the incidence of pediatric DNI in the United States is increasing, but no nationally representative studies exist. This study sought to characterize pediatric DNI at the national level over the past decade and to determine whether U.S. incidence of pediatric DNI and associated resource utilization changed from 2000 to 2009.

METHODS

The Kids' Inpatient Database (KID) was used to evaluate pediatric DNI incidence, demographics, and outcomes from 2000 to 2009. Cases were identified using the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) diagnostic codes for peritonsillar abscess (475), parapharyngeal abscess (478.22), and retropharyngeal abscess (478.24). Regression analyses within each year and across the entire study period were performed on variables of interest including performance of imaging studies, operative intervention, length of hospital stay and total hospital charges.

RESULTS

The incidence of retropharyngeal abscess increased significantly from 0.10 cases per 10,000 in 2000 to 0.22 in 2009 (p=0.02). There was no significant change during this time period in the incidence of combined DNI (1.07-1.37 cases per 10,000, p=0.07), peritonsillar abscess (0.82-0.94 cases per 10,000, p=0.12) or parapharyngeal abscess (0.08-0.14 cases per 10,000, p=0.13). The percentage of retropharyngeal abscess patients managed surgically decreased (48-38%, p=0.04) and the average length of hospital stay also decreased during this time (4.6-3.9 days, p=0.03). There was a marked increase in the total inflation-corrected hospital charges per case for all DNI ($9,486-16,348, p=0.005).

CONCLUSIONS

The incidence of pediatric retropharyngeal abscess has increased significantly from 2000 to 2009, without concurrent increases in the incidence of combined DNI, peritonsillar, or parapharyngeal abscesses. There has been a change in management of retropharyngeal abscesses during this time with a decrease in operative intervention and a decrease in the length of hospital stay. Hospital charges associated with all pediatric DNI have nearly doubled during this timeframe, warranting future epidemiologic resource utilization studies in this population.

Microbiota associated with infections of the jaws

The microbial infections involving the craniofacial skeleton, particularly maxilla and mandible, have direct relationship with the dental biofilm, with predominance of obligate anaerobes. In some patients, these infections may spread to bone marrow or facial soft tissues, producing severe and life-threatening septic conditions. In such cases, local treatment associated with systemic antimicrobials should be used in order to eradicate the sources of contamination. This paper discuss the possibility of spread of these infections and their clinical implications for dentistry, as well as their etiology and aspects related to microbial virulence and pathogenesis.

Microbiology of Acute and Chronic Maxillary Sinusitis in Smokers and Nonsmokers

Objectives:

We evaluated the microbiology of sinus aspirates of smokers and nonsmokers with acute and chronic maxillary sinusitis.

Methods:

Cultures were obtained from 458 patients, 244 (87 smokers and 157 nonsmokers) of whom had acute maxillary sinusitis and 214 (84 smokers and 130 nonsmokers) of whom had chronic maxillary sinusitis, between 2001 and 2007.

Results:

A greater number of Staphylococcus aureus, methicillin-resistant S aureus (MRSA), and beta-lactamase–producing bacteria (BLPB) were found in the 87 smokers with acute sinusitis than in the nonsmokers with acute sinusitis (p < 0.005, p < 0.025, and p < 0.05, respectively). A greater number of these organisms were found in the 84 smokers with chronic sinusitis than in the nonsmokers (p < 0.01, p < 0.025, and p < 0.001, respectively). Eighty-five BLPB isolates were recovered from 73 patients (30%) with acute sinusitis. These included Moraxella catarrhalis, S aureus, Haemophilus influenzae, Prevotella spp, and Fusobacterium spp; 40 BLPB isolates were found in smokers, and 45 in nonsmokers (p < 0.05). One hundred twenty-five BLPB isolates were recovered from 91 patients (43%) with chronic sinusitis, including M catarrhalis, Bacteroides fragilis group, S aureus, H influenzae, Prevotella spp. and Fusobacterium spp; 69 BLPB isolates were found in smokers, and 56 in nonsmokers (p < 0.001). Antimicrobial therapy had been administered in the past month to 130 patients (28%; 60 smokers and 70 nonsmokers; p < 0.025). Both MRSA and BLPB were isolated more often from these individuals (p < 0.025). However, the higher isolation rates of MRSA and BLPB in smokers were independent of previous antimicrobial therapy.

Conclusions:

These data illustrate a greater frequency of isolation of S aureus, MRSA, and BLPB in patients with acute and chronic sinusitis who smoke.

Community-acquired methicillin-resistant Staphylococcus aureus in nasal vestibular abscess

BACKGROUND

Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) is a recognized entity that is increasingly responsible for skin and soft tissue infections. However, it is not the usual pathogen isolated in nasal vestibular abscess.

METHODS

We present a series of 13 consecutive patients presenting to a tertiary care center with nasal vestibular abscess over a 2.5-year period.

RESULTS

All abscesses were cultured and 100% (13/13) grew S. aureus. Of the S. aureus isolates, 92% (12/13) were MRSA. Antibiotic susceptibilities of the MRSA isolates were as follows: 100% were susceptible to rifampin, trimethoprim-sulfamethoxazole, and tetracycline, 75% to clindamycin, 58% to fluoroquinolones, and 17% to erythromycin.

CONCLUSION

MRSA is an important pathogen in the community. It is therefore critical to appreciate its potential predominance in nasal vestibular abscess. Clinicians should obtain cultures, modify antibiotic therapy as warranted, and initiate empiric therapy to include MRSA coverage for nasal vestibular abscess.