Anaerobic bacteria in upper respiratory tract and head and neck infections: microbiology and treatment

Cytobacteriological testing of drainage pus from peritonsillar abscess is not contributive in clinical practice: A STROBE analysis

PURPOSE

Peritonsillar abscess (PTA) is a frequent pathology. Treatment consists in drainage of the collection, associated to probabilistic antibiotic therapy. The usefulness of cytobacteriological testing (CBT) of the drainage pus is controversial.

MATERIAL AND METHODS

A retrospective study of patients managed for PTA between 2013 and 2020 in our university hospital was performed. The main objective was to assess the usefulness of CBT in the management of PTA. The secondary objectives were to determine the bacteriological profile involved in the onset of PTA and to assess the rate of bacterial resistance to antibiotics prescribed on a probabilistic basis.

RESULTS

The study included 207 patients: 70 outpatients (33%) and 137 inpatients (67%). Probabilistic antibiotic therapy was implemented in 100% of patients. CBT was performed systematically and was negative in 106 patients, revealing oropharyngeal flora in 40% of cases, polymicrobial flora in 50% and sterile samples in 10%. In the 101 patients with positive CBT, the bacteria isolated were penicillin-sensitive in 99%. All patients were successfully treated. In the light of the bacteriological results, no changes were made to the probabilistic antibiotic therapy introduced on admission.

CONCLUSION

CBT on drainage pus had no impact on the management of PTA. CBT is therefore unnecessary in patients with no comorbidities and no signs of severity at admission.

Mortality risk factors and fulminant sub-phenotype in anaerobic bacteremia: a 10-year retrospective, multicenter, observational cohort study

PURPOSE

During the last decade, the incidence of anaerobic bacteremia (AB) has been increasing. Patients with AB may develop complex underlying diseases, which can occasionally be accompanied by fatal or fulminant outcomes. However, the risk factors for AB-related mortality remain unclear. Herein, we sought to elucidate the risk factors for AB-related mortality.

METHODS

In this multicenter, retrospective, observational study, we enrolled patients with culture-proven AB from six tertiary hospitals in Japan, between January 2012 and December 2021. Data on patient and infection characteristics, laboratory findings, treatment, and outcome were collected, and their associations with mortality were analyzed.

RESULTS

A total of 520 participants were included. The 30-day mortality in the study cohort was 14.0% (73 patients), and malignant tumors were frequently observed comorbidities in 48% of the entire cohort. Multivariable logistic regression analysis showed a Charlson comorbidity score of > 6, serum creatinine level of > 1.17 mg/dL, and hypotension to be independent risk factors for 30-day mortality in AB (odds ratios [ORs] 2.12, 2.25, and 5.12, respectively; p < 0.05), whereas drainage significantly reduced this risk (OR, 0.28; p < 0.0001). Twelve patients (2.3% of the whole cohort and 16.4% of the deceased patients) presented with extremely rapid progression leading to fatal outcome, consistent with "fulminant AB."

CONCLUSIONS

This study identified acute circulatory dysfunction and performance of drainage as independent predictive factors for 30-day AB-related mortality and revealed the existence of a fulminant AB sub-phenotype. Our findings could serve as a practical guide to predict the clinical outcomes of AB.

The Etiological Bacterial Spectrum of Neck Abscesses of Lymph Node Origin - Gram-Positive and Gram-Negative Bacteria

According to our medical practice as maxillofacial and oral surgeons, operated patients with purulent infections of the cervical lymph nodes are not many in number. On the other hand, the presence of a purulent infection requires not only the surgical evacuation of the pus but also the application of antimicrobial preparations. This necessitates good knowledge of the spectrum of the bacterial causative agents of the disease, the determination and analysis of which is the purpose of this original article. The bacteria studied in 181 patients with a mean age of 26.25 years, ranging between 29 days and 82 years, who underwent surgery for suppurating cervical lymph nodes, were retrospectively analyzed over a period of eight years. No bacteria were found in 69 of them. In 83 (74.11%) of the remaining 112 studied patients, the isolated microorganisms were of the gram-positive spectrum - Staphylococcus aureus (n=34), gram-positive resident microflora represented by more than one bacterial species (n=21), Staphylococcus hemolyticus (n=10), Staphylococcus epidermidis (n=9) and beta-hemolytic streptococci (n=9). Gram-negative bacteria were 25.89% (n=29) - Klebsiella pneumoniae (n=8), Bartonella henselae (n=7), Klebsiella oxytoca (n=6), Enterobacter cloacae (n=5) and Flavimonas oryzihabitans (n=3). No anaerobic and fungal microorganisms were isolated. Therefore, antimicrobial therapy in these patients should be directed against both gram-positive and gram-negative bacteria, which in our study were represented in a ratio of approximately three to one in favor of gram-positive microorganisms. Otherwise, we create a prerequisite for the formation of phlegmon on the neck, which hides real chances for the lives of patients.

Acute Retropharyngeal and Parapharyngeal Abscesses: A Case Series

OBJECTIVE

The purpose of this study was to evaluate the diagnosis circumstances, predisposing factors, investigations, and therapeutic management of retropharyngeal and parapharyngeal abscesses.

METHODS

A retrospective chart review of patients diagnosed with retropharyngeal or parapharyngeal abscess from 2001 to 2021 was performed. Epidemiological characteristics, clinical signs, investigations, medical treatment, and surgical interventions were analyzed for each patient.

RESULTS

A total of 30 patients with retropharyngeal or parapharyngeal abscess were identified. Computed tomography was performed in all cases, and magnetic resonance imaging was performed in three cases. Twelve patients had a "pure" retropharyngeal abscess, nine patients had a prestyloid abscess, one patient had a prestyloid abscess associated with a peritonsillar abscess, three patients had a retrostyloid abscess, and five patients had a prestyloid abscess associated with a retropharyngeal abscess or a retrostyloid abscess. The median long axis of the abscess was 42 cm. All patients received intravenous antibiotics for a median period of 8 days [4-30]. Seventeen patients required surgical trans-cervical drainage. Other patients underwent transoral or transnasal drainage. The pus culture revealed no growth in six cases, streptococcus (four cases), methicillin-sensitive Staphylococcus aureus (two cases), Klebsiella (two cases), Enterobacter (one case), Fungi (two cases), and Mycobacterium tuberculosis (a twelve-year-old boy). It was not documented in twelve cases. Histological examination revealed caseofollicular tuberculosis in a 53-year-old man. In 25 patients, no adverse events were observed during follow-up. Five patients had an unfavorable outcome.

CONCLUSION

We have found an increase in the incidence of these infections in recent years. Computed tomography is the best imaging examination for the diagnosis and follow-up of retropharyngeal and parapharyngeal abscess. Early drainage and antimicrobial therapy are essential for rapid recovery and prevention of complications of these abscesses.

Veillonella atypica causing retropharyngeal abscess: A rare case presentation

Veillonella species are obligate anaerobes which are part of the human oral, gut and vaginal microbiota. The genus Veillonella consists of 16 characterized species. Very few infections due to Veillonella atypica have been reported till date. Here we present a case of retropharyngeal abscess due to this organism in a 55-year-old lady.

Development of multiplex PCR panel for detection of anaerobic bacteria in clinical samples

OBJECTIVE

Although anaerobic bacteria are important agents of a wide variety of serious infections, they are overlooked often in the etiology of infection due to difficulties in isolation and detection. The aim of this study was to develop a new multiplex PCR panel that could detect Bacteroides, Fusobacterium, Prevotella, Veillonella, Clostridium, Peptostreptococcus, and Actinomyces bacteria, which are the most frequently isolated from anaerobic infections, at the genus level.

METHOD

Aerobic and anaerobic cultures were performed on 46 clinical specimens, with suspicion of anaerobic infection and were sent to the laboratory. DNA isolation was performed with the same samples and anaerobic bacteria were detected by the multiplex PCR test developed in the study.

RESULT

The analytical sensitivity of the multiplex PCR assay was found to be 1-10³ CFU/ml, depending on the bacterial species. In this study, anaerobic growth was observed in eight (17.4%) of 46 clinical samples. The multiplex PCR test detected 35 anaerobic bacteria from 20 (43.5%) of 46 clinical samples. The most common anaerobes isolated from clinical specimens by the multiplex PCR assay were Prevotella spp. (37.1%) and Fusobacterium spp. (22.9%) while Clostridium spp. (14.3%), Peptostreptococcus spp. (11.4%), Bacteroides spp. (8.6%), and Veillonella spp. (5.7%) followed these genera.

CONCLUSION

As a result, it was concluded that the multiplex PCR panel developed in this study eliminates problems in the detection of anaerobes based on culture, provides more accurate detection of anaerobic bacteria from clinical specimens, takes a shorter time, and allows more accurate infection treatment.

Paediatric Deep Neck Infection—The Risk of Needing Intensive Care

Deep neck infections are potentially dangerous complications of upper respiratory tract or odontogenic infections. The pathophysiology, clinical presentation, and potential spreading depend on the complex anatomy of the neck fascia. These infections can lead to severe pathological conditions, such as mediastinitis, sepsis, and especially airway impairment with difficult management. Because of the risk of life-threatening emergency situations and the possible impacts on the overall health status of affected children, their early recognition is of utmost importance. Torticollis, drooling, and stridor are the most common signs of advancing disease. Children presenting with these symptoms should be admitted to the paediatric intensive care unit for vital function monitoring, where the airway could be readily secured if function is compromised.

Bacteriological analysis based on disease severity and clinical characteristics in patients with deep neck space abscess

Background

Deep neck space abscess (DNSA) is a serious infection in the head and neck. Antibiotic therapy is an important treatment in patients with DNSA. However, the results of bacterial culture need at least 48 h, and the positive rate is only 30–50%, indicating that the use of empiric antibiotic treatment for most patients with DNSA should at least 48 h or even throughout the whole course of treatment. Thus, how to use empiric antibiotics has always been a problem for clinicians. This study analyzed the distribution of bacteria based on disease severity and clinical characteristics of DNSA patients, and provides bacteriological guidance for the empiric use of antibiotics.

Methods

We analyzed 433 patients with DNSA who were diagnosed and treated at nine medical centers in Guangdong Province between January 1, 2015, and December 31, 2020. A nomogram for disease severity (mild/severe) was constructed using least absolute shrinkage and selection operator–logistic regression analysis. Clinical characteristics for the Gram reaction of the strain were identified using multivariate analyses.

Results

92 (21.2%) patients developed life-threatening complications. The nomogram for disease severity comprised of seven predictors. The area under the receiver operating characteristic curves of the nomogram in the training and validation cohorts were 0.951 and 0.931, respectively. In the mild cases, 43.2% (101/234) had positive culture results (49% for Gram-positive and 51% for Gram-negative strains). The positive rate of cultures in the patients with severe disease was 63% (58/92, 37.9% for Gram-positive, and 62.1% for Gram-negative strains). Diabetes mellitus was an independent predictor of Gram-negative strains in the mild disease group, whereas gas formation and trismus were independent predictors of Gram-positive strains in the severe disease group. The positivity rate of multidrug-resistant strains was higher in the severe disease group (12.1%) than in the mild disease group (1.0%) (P < 0.001). Metagenomic sequencing was helpful for the bacteriological diagnosis of DNSA by identifying anaerobic strains (83.3%).

Conclusion

We established a DNSA clinical severity prediction model and found some predictors for the type of Gram-staining strains in different disease severity cases. These results can help clinicians in effectively choosing an empiric antibiotic treatment.

Deep Neck Abscesses in Children: An Italian Retrospective Study

BACKGROUND

Retropharyngeal and parapharyngeal abscesses (RPAs, PPAs) usually affect young children. Surgical drainage and/or antibiotic therapy are treatment of choice, but no specific guidelines exist. In order to reduce the risk of severe complications, appropriate diagnosis and therapy are necessary. The aims of the study were to review diagnosis and management of children with RPAs/PPAs and to compare surgical versus medical approach.

METHODS

This is a multicenter retrospective study including all patients younger than 15 years admitted at 4 Italian pediatric hospitals of Florence, Padua, Rome, and Treviso, with International Classification of Diseases, Ninth Revision discharge diagnosis code of RPAs and PPAs, from January 1, 2008, to December 31, 2016.

RESULTS

One hundred fifty-three children were included. The median age was 4.4 years, with overall male predominance. Heterogeneous signs and symptoms (fever, neck cervical, lymphadenopathy, pain, and stiff neck most frequently) and a large mixture of bacteria from pus cultures were detected. Computer tomography (66.7%) and magnetic resonance imaging (27.5%) were performed to confirm the presence of abscess. Fifty-one percent of abscesses were greater than 3 cm. Eighty-seven patients (56.9%) underwent surgery, and 66 (43.1%) were treated with antibiotics alone (mostly ceftriaxone, metronidazole, amikacin, and clindamycin) with median days of therapy of 26.5 days and length of therapy of 16.0 days of median. Median length of stay was 11 days. None had severe complications. Multivariate analysis indicated as independent predictive factors of surgery abscess of 3 cm or greater, high white blood cell count, and-most of all-the hospital of admission.

CONCLUSIONS

Deep neck abscesses mostly affect patients in early childhood, with a combination of nonspecific signs and symptoms, and it still emerges as a heterogeneous approach in diagnosis and management of these infections. Thus, common shared protocols represent an essential tool in order to standardize care and improve patients' outcomes.

Antimicrobial and Antibiofilm Activities of Weissella cibaria against Pathogens of Upper Respiratory Tract Infections

Recently discovered preventive effects of probiotics on oral health have attracted interest to their use for the prevention and treatment of various diseases. This study aimed to evaluate the antimicrobial and antibiofilm properties of Weissella cibaria against Streptococcus pyogenes, Staphylococcus aureus, S. pneumoniae, and Moraxella catarrhalis, the major pathogens of upper respiratory tract infections (URTIs). The antimicrobial activities of W. cibaria were compared with those of other oral probiotics using a competitive inhibition assay and the determination of the minimum inhibitory concentrations (MICs). In addition, a time-kill assay, spectrophotometry, and confocal laser scanning microscopy were used to confirm the antimicrobial and antibiofilm abilities of W. cibaria CMU (oraCMU) and CMS1 (oraCMS1). Both live cells and cell-free supernatants of all tested probiotics, except Streptococcus salivarius, showed excellent antimicrobial activities. All target pathogens were killed within 4 to 24 h at twice the MIC of oraCMU and oraCMS1, which showed the highest antimicrobial activities against M. catarrhalis. The antimicrobial substances that affected different target pathogens were different. Both oraCMU and oraCMS1 showed excellent abilities to inhibit biofilm formation and remove preformed biofilms. Our results suggest that the W. cibaria probiotics offer new possibilities for the prevention and treatment of bacterial URTIs.

The characterization of bacterial communities of oropharynx microbiota in healthy children by combining culture techniques and sequencing of the 16S rRNA gene

The high incidence of bacterial respiratory infections has led to a focus on evaluating the human respiratory microbiome. Studies based on culture-based and molecular methods have shown an increase in the bacterial community that includes the bacterial phyla Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria in the oropharynx of healthy individuals. Therefore, recognizing this microbial compound and subsequently identifying those carriers of specific pathogens can be of great help in predicting future infections and their control. In this prospective study, we sought to characterize the bacterial communities of the respiratory microbiome in healthy children aged between 3 and 6 years old by combining both cultural techniques and sequencing of the 16S rRNA gene. Seventy-seven oropharynx samples using Dacron swabs were collected from 77 healthy children in the kindergartens of Ilam, Iran. Bacterial identification was performed by phenotypic methods and in house developed PCR-based sequencing (the V1-V9 hypervariable region of the bacterial 16S ribosomal RNA gene). In total, 346 bacterial isolates were characterized based on phenotypic and sequencing-based molecular methods. The 3 most predominant phyla were Firmicutes (74%), Proteobacteria (22%), and Actinobacteria (4%). At the level of the genus, Staphylococci (coagulase-positive and coagulase-negative) and Streptococci were dominant. Also, the most commonly identified potentially pathogenic colonisers were S. aureus (75%), Enterobacteriaceae spp. (40.1%), and A. baumannii (15.6%). The present study identified 3 phyla and 9 family of bacteria in the oropharyngeal microbiome. Remarkably, the presence of potential pathogenic bacteria in the nasopharynx of healthy children can predispose them to infectious diseases, and also frequent exposure to human respiratory bacterial pathogens are further risk factors.

Propionibacterium acnes-associated chronic hypertrophic pachymeningitis followed by refractory otitis media: a case report

BACKGROUND

Hypertrophic pachymeningitis (HP) is a rare disorder that involves localized or diffuse thickening of the dura mater. HP is associated with various inflammatory, infectious, and malignant diseases, such as rheumatic arthritis, sarcoidosis, anti-neutrophil cytoplasmic antibody-associated vasculitis, IgG4-related disorders, syphilis, tuberculosis, bacterial and fungal infections, cancer, and idiopathic diseases, when evaluation fails to reveal a cause. Among them, chronic infection with Propionibacterium acnes is a rare etiology of HP, and its pathology remains unclear.

CASE PRESENTATION

An 80-year-old man having refractory otitis media with effusion of the right ear presented with progressive right-sided headache and nausea. Post-contrast brain magnetic resonance imaging revealed right mastoiditis and remarkable thickening of the dura mater and enhancement of pia mater extending from the right middle cranial fossa to the temporal lobe. HP secondary to middle ear infection was suspected, and a biopsy of the right mastoid was performed. An anaerobic culture of the biopsied right mastoid showed the growth of P. acnes, and histopathological examination using P. acnes-specific monoclonal antibody (PAB antibody) revealed the infiltration of inflammatory cells with P. acnes. Moreover, using PAB antibody, P. acnes was detected in the biopsy specimen of the thickening dura mater. No granulomas were identified in either specimen. HP was resolved with long-term administration of antibiotics and steroids.

CONCLUSION

This is the first documentation of pathologically demonstrated chronic HP associated with P. acnes infection followed by refractory otitis media. This report showed that chronic latent P. acnes infection induces chronic inflammation.

Prospective observational case series evaluating middle ear fluid and tympanostomy tubes through pyrosequencing

OBJECTIVE

One of the most common sequelae of tympanostomy tube (TT) placement is post-tympanostomy tube otorrhea (PTTO). Granulation tissue formation has been reported in 5-13.8% of patients with TT placement. The purpose of this study is to determine the biodistribution of microorganisms on TTs and middle ear fluid obtained from patients with PTTO.

METHODS

This was a prospective observational study of subjects (6-months-16-years) who underwent standard of care treatment for chronic PTTO. Data was collected on diagnosis, existence of antibiotic resistance, duration of tube placement, and evidence of recurrent infection and/or PTTO. TTs and middle ear fluid were subjected to pyrosequencing; additionally, ear fluid samples were sent for culture-based laboratory diagnostics.

RESULTS

DNA-pyrosequencing analysis of bacteria from fluid and TTs of pediatric subjects with PTTO revealed a mixture of both aerobic and anaerobic populations. Retained tubes with minimal otorrhea revealed a predominance of Staphylococcus species, normal external auditory canal (EAC) microbiome, within middle ear fluid as well as on TTs. However, TTs with active mucopurulent otorrhea and granulation tissue unveiled prominence of Gram-negative facultative anaerobes such as Pseudomonas and Eikenella. Discrepancies in prominent bacteria were seen between standard culture-based techniques versus pyrosequencing.

CONCLUSION

Retained tympanostomy tubes are colonized primarily with normal flora of the EAC. However, mucopurulent otorrhea associated with granulation tissue formation revealed a prominence of Gram-negative facultative anaerobes. Standard culture-based diagnostics may identify bacteria, which are not predominant species of infection. Future studies are necessary to assess the association of Gram-negative facultative anaerobes with granulation tissue formation.

Planktonic Growth of Pseudomonas aeruginosa around a Dual-Species Biofilm Supports the Growth of Fusobacterium nucleatum within That Biofilm

PURPOSE

The goal of this study was to understand the potential interaction between Pseudomonas aeruginosa and Fusobacterium nucleatum within the middle ear.

METHODS

We examined the microbiota of ear fluid and tympanostomy tubes (TTs) obtained from patients with posttympanostomy tube otorrhea. We also examined biofilms formed by P. aeruginosa and F. nucleatum, singly or together, under aerobic or anaerobic conditions.

RESULTS

While the facultative anaerobe P. aeruginosa dominated the bacterial population within the ear fluid, strict anaerobes, including F. nucleatum, dominated bacterial populations within the TTs. F. nucleatum was able to grow under aerobic conditions only in the presence of P. aeruginosa, whose growth reduced the level of dissolved oxygen within the broth to nearly anoxic condition within 4 h after inoculation. The presence of P. aeruginosa allowed F. nucleatum to maintain its growth for 72 h within the dual-species biofilm but not within the planktonic growth. Visualization of the biofilms revealed coaggregation of P. aeruginosa and F. nucleatum.

CONCLUSION

Extrapolation of these results suggests that, within the middle ear fluid, the growth of P. aeruginosa produces the anaerobic conditions required for the growth of F. nucleatum, both within effusion and within biofilms.

Bacterial and histopathological findings in deep head and neck infections: a retrospective analysis

OBJECTIVES

Deep neck infections are among the most dangerous acute diseases in the head and neck region. This analysis gives an overview of the bacterial and histopathologic findings of deep neck infections.

STUDY DESIGN

From January 2002 to December 2012, 63 patients were diagnosed with and treated for deep neck infections at the University Medical Center Göttingen. Bacterial and histopathologic examinations were made, and the occurrence of bacterial pathogens and histopathologic findings were analyzed.

RESULTS

The most commonly isolated aerobic gram-positive pathogen was Streptococcus viridans (26.7%); Staphylococcus epidermidis and Staphylococcus aureus were each found in 16.7% of infections. The most commonly isolated aerobic gram-negative pathogens were Escherichia coli, Klebsiella oxytoca, and Haemophilus influenzae. In 1.6% of patients, a malignant cancer was detected.

CONCLUSION

For clear diagnosis and effective therapy, a bacteriologic investigation of deep neck infections is essential because of the heterogeneous spectrum of the detected bacteria. In contrast to Asia, where Klebsiella pneumoniae is the most common pathogen, in South Lower Saxony, Germany, we discovered a dominating spectrum of aerobic gram-positive cocci. Biopsy obtained from an abscess cavity for histologic examination should always be part of the diagnostic process in order to exclude a malignant process.

[Rational antibiotic treatment of mediastinitis]

Mediastinitis occurs as a severe complication of thoracic and cardiac surgical interventions and is the result of traumatic esophageal perforation, conducted infections or as a result of lymphogenic and hematogenic spread of specific infective pathogens. Treatment must as a rule be accompanied by antibiotics, whereby knowledge of the spectrum of pathogens depending on the pathogenesis is indispensable for successful antibiotic therapy. Polymicrobial infections with a high proportion of anaerobes are found in conducted infections of the mediastinum and after esophageal perforation. After cardiac surgery Staphylococci are the dominant pathogens and a nasal colonization with Staphylococcus aureus seems to be a predisposing risk factor. Fungi are the predominant pathogens in immunocompromised patients with consumptive underlying illnesses and can cause acute or chronic forms with granulomatous inflammation. Resistant pathogens are increasingly being found in high-risk patient cohorts, which must be considered for a calculated therapy. For calculated antibiotic therapy the administration of broad spectrum antibiotics, mostly beta-lactams alone or combined with metronidazole is the therapy of choice for both Gram-positive and Gram-negative bacteria inclusive of anaerobes. For patients at risk, additional antibiotic classes with a spectrum against methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) can be administered. Increasing rates of multidrug-resistant Gram-negative bacteria (e.g. Enterobacteriaceae) and non-fermenting bacteria (e.g. Pseudomonas and Acinetobacter) in individual cases necessitates the use of polymyxins (e.g. colistin), new tetracyclines (e.g. glycylglycines) and newly developed combinations of beta-lactams and beta-lactam inhibitors. For treatment of fungal infections (e.g. Candida, Aspergillus and Histoplasma) established and novel azoles, amphotericin B and echinocandins seem to be successful; however, detection of Candida, particularly in mixed infections does not always necessitate treatment. Mediastinitis is still a severe infectious disease with a high mortality, which necessitates an early and broad spectrum antibiotic therapy; however, with respect to optimal duration of therapy and selection of antibiotics, data from good quality comparative studies are lacking.

Deep Neck Infection and Descending Mediastinitis as a Complication of Propionibacterium acnes Odontogenic Infection

Propionibacterium acnes is an anaerobic, Gram-positive bacterium which causes numerous types of infections. Isolated Propionibacterium acnes deep neck infections are very rare. We present an interesting case of deep neck infection complicated by descending mediastinitis of isolated Propionibacterium acnes infection.

Microbial Flora and Antibiotic Resistance in Peritonsillar Abscesses in Upstate New York

OBJECTIVES

To identify the common bacteria in recent peritonsillar abscesses and the prevalence of antibiotic resistance and compare both between adults and children.

METHODS

This is a retrospective chart review at a single academic institution of patients who underwent either incision and drainage or tonsillectomy for a peritonsillar abscess between 2002 and 2012 (n=69). Medical records were reviewed for cultures, comorbidities, and drainage procedures.

RESULTS

Cultures obtained from 62.32% of peritonsillar abscesses were polymicrobial, and 34.78% were monomicrobial. The most common pathogens were β-hemolytic Streptococcus (31.88%), α-hemolytic Streptococcus (21.74%), Neisseria (14.49%), and Streptococcus milleri (13.04%). Group A β-hemolytic streptococcus was more common in children and Streptococcus milleri was more common in adults. Alpha-hemolytic streptococcus was resistant to clindamycin (6.67%) and erythromycin (6.67%). Streptococcus milleri was resistant to clindamycin (11.11%) and erythromycin (11.11%). Staphylococcus was resistant to penicillin (37.5%), oxacillin (25%), erythromycin (25%), and clindamycin (12.5%).

CONCLUSIONS

β- and α-hemolytic Streptococci, Neisseria, and Streptococcus milleri are the most common pathogens. Streptococcus milleri is more common in adults, and β-hemolytic streptococcus is more common in children. Resistance to clindamycin and erythromycin is common in Streptococci and Staphylococci, and penicillin resistance is common in Staphylococci.

Microarray identification of bacterial species in peritonsillar abscesses

Peritonsillar abscess (PTA) is the most common otorhinolaryngological infection, requiring management at the special healthcare level. The microbiological findings vary due to geographical, etiological, and methodological factors. This study aimed to identify the bacterial species of PTAs by using a novel polymerase chain reaction (PCR)- and microarray-based assay, and to find causative cofactors among patients with different pathogens. We determined the bacterial findings of aspirates of pus prospectively collected from 180 PTA patients. Samples were pretreated prior to nucleic acid extraction and analyzed with a PCR- and microarray-based assay or DNA sequencing. Both methods were based on the gyrB/parE topoisomerase genes. Patients answered symptom questionnaires at admission, and their medical records were reviewed later. Altogether, 160 (89 %) aspirates of pus tested positive for bacteria, and a bacterial species was identified in 149 (83 %) of the samples. A polybacterial species was detected in 20 (13 %) and anaerobic bacteria in 77 (52 %) of the 149 samples. Fusobacterium necrophorum patients were younger (p < 0 .001) and had more severe symptoms (p = 0.04) than patients with other pathogens. Gender, smoking, or preadmission antibiotics showed no correlation with any of the pathogens. Although requiring some optimization, this microarray assay seems feasible and fast for bacterial identification directly from pus samples, and confirms the diversity of PTA pathogens. Young patients with more severe symptoms may require special attention. Species-specific antibiotic treatment of PTA remains challenging due to bacterial variations; the present assay may aid in specifying PTA antibiotic treatment in the future.

Severe neck infections that require wide external drainage: clinical analysis of 17 consecutive cases

Infections in the neck layers and spaces are potentially life-threatening diseases causing further complications, like mediastinitis, airway obstruction, or sepsis. Despite of the need for a conservative approach, they still regularly require surgical intervention. Records of 17 patients with severe neck infections that were treated by wide external incision and open wound management were retrospectively analyzed. The aim of the study was to clinically characterize these most serious neck infections. The most common presenting symptoms were neck pain and tense neck mass (94-94%) regularly with fever (65%), always accompanied by a marked elevation of C reactive protein level (average 192 uG/l). These findings were constant and very similar among both the deep neck infection and necrotizing fasciitis cases. More than half of the patients (53%) had at least one systemic co-morbidity. The parapharyngeal space was most commonly affected (83%), but extended disease involving more than two major neck regions was found in 13 cases (76%). Dental (29%) was the most common primary infection, followed by peritonsillar abscess (23%), Microbiological results showed a wide variety of corresponding bacteria. Mediastinitis was developed in three cases (18%), and airway obstruction requiring tracheostomy in two cases (12%). All the patients survived. Severe neck infections are a heterogenous group of diseases regarding to the primary site of infection, microbiology, localisation and host reaction. However, rapidly developed, painful, tense neck mass with a highly elevated CRP level should always alert for an extended or phlegmonous process in the layers or spaces of the neck.

Acute Respiratory Distress Syndrome in Lemierre's Syndrome

Lemierre's syndrome is an infectious disease defined by the presence of septic thrombophlebitis with associated embolic phenomenon, most commonly to the lungs. Here we present two cases from a single institution of acute respiratory distress syndrome (ARDS) developing as a result of Lemierre's syndrome in previously healthy young adult men. ARDS can occur as a consequence of pulmonary septic emboli and sepsis, both of which are well-described consequences of Lemierre's syndrome. We describe important diagnostic and management considerations in the care of patients with hypoxemic respiratory failure and Lemierre's syndrome. Essential components of management include prompt antibiotic therapy, lung-protective ventilation strategies, and supportive care.

Establishment of a new murine model of liver abscess induced by Fusobacterium necrophorum injected into the caudal vein

Anaerobic bacterial infection is often accompanied by abscess formation; however, few in vivo studies have been published with descriptive data specifically evaluating antimicrobial activity in the presence of abscesses. The aim of this study was to establish a murine model of anaerobic infection with abscess formation and to verify the utility of this model for evaluating the in vivo efficacy of an antimicrobial agent. A clinical isolate of Fusobacterium necrophorum was inoculated into the caudal vein of immunocompetent BALB/c mice at 108 c.f.u. per mouse. Changes in body weight, bacterial load and histopathology of key organs were evaluated. After inoculation, bacterial counts in the liver increased from 104 to 108 c.f.u. after 1–3 days, and liver abscess formation was observed on the day following infection. Abscess formation and bacterial growth were not observed in other organs. In this model, 3 days of treatment with 5 mg metronidazole kg−1 eradicated F. necrophorum in the liver; however, a reduction in bacterial load was not observed with 0.05 mg metronidazole kg−1. In this study, we established a novel murine model of F. necrophorum liver abscess via haematogenous infection that may be useful for investigating in vivo antimicrobial activity against anaerobic abscesses and understanding the pathogenesis of F. necrophorum infection.