Anaerobic bacteria in 118 patients with deep-space head and neck infections from the University Hospital of Maxillofacial Surgery, Sofia, Bulgaria

Evaluation of Antibiotic Sensitivity in Deep Neck Space Infections

Background Deep neck space infections (DNIs) are a major medical concern in the Indian community. Owing to the complex anatomy of the neck spaces and their communication with each other, accurate diagnosis becomes challenging. A thorough knowledge of the anatomy as well as the microbiological profile and antibiotic sensitivity is imperative to institute the appropriate surgical and medical management to the patient. Due to the advent of broad-spectrum antibiotics, the incidence of these infections have declined considerably over the last couple of decades. However, due to the extensive and unregulated use, the incidence of antibiotic resistance has also been increasing at an alarming pace.

Materials and Methods This cross-sectional observational study was conducted in the Department of Otorhinolaryngology at a tertiary care government hospital in an urban area. All patients who presented to the OPD or emergency over a period of 18 months and who fulfilled the eligibility criteria were included in the study. Pus was collected from the abscess, aseptically by needle aspiration using wide bore (18G) needle and transported under all aseptic measures within 24 hours for culture and sensitivity, KOH mount, and detection of AFB. Antibiotic sensitivity testing was done using the Kirby Bauer disc diffusion method and E-test.

Results Staphylococcus aureus as the most common infective organism followed by MRSA in the pediatric age group and Klebsiella pneumoniae in adults.

Conclusion Primary knowledge of individual antibiotic sensitivity is imperative to ensure prompt and adequate treatment of the patient with higher chances of complete resolution, concomitantly minimizing the risk of resistance. Inadequate and delayed treatment may lead to swift progression of the disease with significant morbidity and mortality.

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.

Microbiological profile of aerobic and anaerobic bacteria and its clinical significance in antibiotic sensitivity of odontogenic space infection: A prospective study of 5 years

Introduction:

Odontogenic infections are mixed aerobic-anaerobic microbial flora. Infections caused by anaerobic bacteria are serious and life-threatening. The microbial specificity in odontogenic infections is technique sensitive depending on the sampling and culturing of specimens.

Materials and Methods:

A prospective study was carried out on 100 consecutive cases of odontogenic infections treated at our institute over a period of 5 years by surgical intervention and intravenous antibiotics. This study evaluates the pathogenic potential and virulence factors of aerobes and anaerobes as well as its synergistic interrelations with other infectious flora, by culturing of specimens and testing antibiotic sensitivity in standard microbiological methodology in correlation with patient demographic factors.

Results:

Of the 100 patients of odontogenic space infection, males were more affected, between third and fourth decades. Caries is the most common etiology with involvement of mandibular molars. Submandibular and buccal space is commonly involved. The most common microorganisms isolated being Staphylococcus aureus and Streptococcus viridans are facultative anaerobes which belong to aerobes and Peptostreptococcus predominated among obligate anaerobes. The empirical antibiotic regimen followed is amoxicillin plus clavulanic acid with Metronidazole, followed by surgical treatment. Clindamycin was preferred as the second line of choice in patients resistance to penicillin drugs with comparable efficacy in it.

Conclusion:

Our study expanded the knowledge base of the microbial flora associated with odontogenic infections, with special reference to anaerobes. Successful management of odontogenic space infection lies in decompression, removal of etiological factors, and also in selecting appropriate antimicrobial therapy depending on microbial flora isolated, for recovery of patients and preventing complications associated with fascial space infection.

Cefazolin versus ampicillin/sulbactam as an empiric antibiosis in severe odontogenic neck infection descending from the lower jaw-retrospective analysis of 350 cases

OBJECTIVES

Odontogenic infections descending from the lower jaw may lead to severe health conditions. Commonly, a biphasic treatment of surgical drainage and antibiotic therapy is conducted. The choice of the administered empiric antibiotic agent remains debatable.

MATERIAL AND METHODS

Retrospectively, we analyzed 350 medical records of patients who were consecutively treated with odontogenic infections descending from the lower jaw. All patients received surgical drainage and either cefazolin or ampicillin/sulbactam as empiric antibiosis. In particular, the number of secondary operations, infectious parameters, and length of in-hospital stay were investigated.

RESULTS

The most frequently infected space was the perimandibular/buccal space for both groups followed by the submandibular space. Number of revision procedures, early recurrence, and length of stay presented no significant difference between both groups (p > 0.05). Inflammatory parameters (c-reactive protein, leukocytes) similarly decreased in both groups.

CONCLUSION

Cefazolin targets the majority of the pathogens detected in severe odontogenic neck infections descending from the lower jaw and reveals comparable results to AMP/S in regard to the inflammatory parameters and in-hospital stay.

CLINICAL RELEVANCE

Cefazolin is a feasible empiric antibiosis for odontogenic neck infections descending from the lower jaw if surgical drainage is performed.

Prevention of infective endocarditis and bacterial resistance to antibiotics: A brief review

The purpose of this statement is to debate the recommendations of the American Heart Association (AHA) for the prevention of infective endocarditis through an antibiotic prophylaxis protocol and its relation with bacterial resistance to antibiotics. Since dental infections involve biofilms that include several bacterial species (Gram-negative and Gram-positive), it is essential, from the dental point of view, to consider the frequency, magnitude, and duration of bacteremia associated with active dental infections before applying antibiotic prophylaxis. The actual guidelines for antibiotic prophylaxis should be revised according to recent evidence of bacterial resistance. Amoxicillin/clavulanic acid and moxifloxacin should be considered due to their effectiveness against bacteria associated with oral, GU, and GI infections and the low rates of antibiotic resistance associated with these antibiotics, instead of the actual protocol, which includes amoxicillin (2 g) or clindamycin (600 mg) administered an hour before the dental procedures. The breaking point to test the antibiotic bacterial resistance (ABR) had a wide range in the different studies that were analyzed, which could explain the widely varied ABR percentages reported for the various antibiotics used for antibiotic prophylaxis.

The pathogenic microbial flora and its antibiotic susceptibility pattern in odontogenic infections

Suppurative head and neck infections of odontogenic origin are the most frequent type of head and neck infections. According to the literature, 7-10% of all antibiotics are currently prescribed for their treatment. Since penicillin was invented, the overall antibiotic sensitivity and resistance pattern of the isolated pathogenic microflora has continuously changed. The response of microorganisms to antibiotics and the development of resistance to their action is a purely evolutive process characterized by genetic mutations, acquisition of genetic material or alteration of gene expression and metabolic adaptations. All this makes challenging and difficult the correct choice of empirical antibiotic treatment for head and neck space infections even today. The aim of this paper was to evaluate the literature and to evidence the most frequent locations of odontogenic head and neck infections, the dominant pathogenic microbial flora, the genetic mutations and metabolic changes necessary for bacteria in order to aquire antibiotic resistance and as well its susceptibility and resistance to common antibiotics. We also aimed to highlight the possible changes in bacterial resistance to antibiotics over time, and to assess whether or not there is a need for fundamental changes in the empirical antibiotic treatment of these infections and show which these would be.

Deep neck infection and descending mediastinitis as lethal complications of dentoalveolar infection: two rare case reports

Background

We report two cases of innocuous dentoalveolar infections which rapidly progressed to deep neck abscesses complicated by descending mediastinitis in a resource-constrained rural mission hospital in the Cameroon.

Case presentation

The clinical presentations of a 35-year-old man and a 32-year-old woman both of Fulani origin in the Northern region of Cameroon were similar with submandibular fluctuant and tender swelling and differential warmth to palpation. The patients had tachycardia, high grade pyrexia, and normal blood pressure. Further physical and neurological examinations were unremarkable. An ultrasound scan of the neck swellings showed submandibular turbid collections. Plain chest radiographs confirmed empyema thoraces. Our patients had serial drainage of the neck abscesses as well as closed thoracostomy tube drainage which were connected to pleurovac and suctioning machines, with significant amount of pus drainage. Both patients were admitted to our intensive care unit for close monitoring. The first patient continued to make satisfactory clinical progress and was discharged by the fourth week of admission. The patient who had human immunodeficiency viral infection died on the fifth postoperative day.

Conclusions

The possibility of lethal complications and the associated morbidity and mortality portray this clinical entity as an important public health concern. Clinicians taking care of patients with dentoalveolar and oropharyngeal infections need to be sensitized to these potentially fatal complications. Alternatively, strategies to improve oral health and reduce the incidence of dental caries, the main cause of dental abscess, would maximize use of resources; especially in resources-constrained centers like ours in Banso Baptist Hospital.

Deep neck infection after third molar extraction: A case report

Deep neck infections are associated with high morbidity rates in dentistry. Early diagnosis and intervention play an essential part in decreasing morbidity rates. The present study aims to report a case of odontogenic deep neck infection after third molar extraction. A 51-year-old male patient underwent extraction of the mandibular right third molar. Seven days later, the patient developed symptoms and signs of progressive infection. Laboratorial and radiologic examinations in association with clinical investigations confirmed deep neck infection. Extraoral drainage was performed under orotracheal intubation. Postoperative laboratory tests and clinical examinations revealed signs of complete remission within a follow-up period of 10 days. Considering the invasive nature of pathogens related to deep neck infections, it is possible to infer that a combination of accurate diagnosis and early intervention plays an essential role in the field of maxillofacial surgery and pathology.

Anaerobic Bacteria in Clinical Specimens - Frequent, But a Neglected Lot: A Five Year Experience at a Tertiary Care Hospital

INTRODUCTION

Anaerobic bacteria which constitute a significant proportion of the normal microbiota also cause variety of infections involving various anatomic sites. Considering the tedious culture techniques with longer turnaround time, anaerobic cultures are usually neglected by clinicians and microbiologists.

AIM

To study the frequency of isolation of different anaerobic bacteria from various clinical specimens.

MATERIALS AND METHODS

A retrospective study to analyse the frequency of isolation of different anaerobic bacteria, was conducted over a period of five years from 2011 to 2015 including various clinical specimens submitted to anaerobic division of Microbiology laboratory. Anaerobic bacteria were isolated and identified following standard bacteriological techniques.

RESULTS

Pathogenic anaerobes (n=336) were isolated from 278 (12.48%) of overall 2227 specimens processed with an average yield of 1.2 isolates. Anaerobes were isolated as polymicrobial flora with or without aerobic bacterial pathogens in 159 (57.2%) patients. Anaerobic Gram-negative bacilli (140, 41.7%) were the predominant isolates. B. fragilis group (67, 19.9%) were the most commonly isolated anaerobic pathogens. Anaerobes were predominantly isolated from deep seated abscess (23.9%).

CONCLUSION

Pathogenic anaerobes were isolated from various infection sites. Unless culture and susceptibility tests are performed as a routine, true magnitude of antimicrobial resistance among anaerobic pathogens will not be known. Knowledge of the distribution of these organisms may assist in the selection of appropriate empirical therapy for anaerobic infections.

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.

Empiric systemic antibiotics for hospitalized patients with severe odontogenic infections

INTRODUCTION

Odontogenic infections may lead to severe head and neck infections with potentially great health risk. Age, location of purulent affected sites and beta-lactam allergy are some mentionable factors regarding patients' in-hospital stay and course of disease. Are there new challenges regarding bacteria' antibiotic resistance for empiric treatment and what influences do they have on patients' clinical course?

METHODS

We analyzed in a 4-year retrospective study the medical records of 294 in-hospital patients with severe odontogenic infections. On a routine base bacteria were identified and susceptibility testing was performed. Length of stay in-hospital was evaluated regarding patients' age, beta-lactam allergy profile, affected sites and bacteria susceptibility to empiric antibiotics.

RESULTS

Length of stay in-hospital was detected to be associated with affected space and penicillin allergy as well (p < 0.05). Isolates presented large amounts of aerobic gram-positive bacteria (64.2%), followed by facultative anaerobic bacteria (gram+/15.8%, gram-/12.7%). Tested ampicillin in combination with sulbactam (or without) and cephalosporins displayed high susceptibility rates, revealing distinguished results regarding clindamycin (p < 0.05). Co-trimoxazol and moxifloxacin showed high overall susceptibility rates (MOX: 94.7%, COTRIM: 92.6%).

DISCUSSION

This study demonstrates ampicillin/sulbactam in addition to surgical intervention is a good standard in treatment of severe odontogenic neck infections. Cephalosporins seem to be a considerable option as well. If beta-lactam allergy is diagnosed co-trimoxazol and moxifloxacin represent relevant alternatives.

CONCLUSION

Age, allergic profile and bacteria' resistance patterns for empiric antibiotics have an influence on patients in-hospital stay. Ampicillin/sulbactam proves itself to be good for empiric antibiosis in severe odontogenic infections. Furthermore cephalosporins could be considered as another option in treatment. However moxifloxacin and co-trimoxazol deserves further investigation as empiric antibiosis in odontogenic infections if beta-lactam allergy is diagnosed.

Deep Neck infections of Odontogenic Origin and Their Clinical Significance. A Retrospective Study from Hradec Králové, Czech Republic

Introduction: Cellulitis remains a very serious disease even today. Mortality, which varied between 10–40%, has been reduced owing to the standard securing of airway patency and use of an appropriate surgical treatment approach. Materials and methods: A total of 195 patients were hospitalised for cellulitis at the University Hospital in Hradec Králové during 2007–2011. The following parameters were evaluated: age, gender, dependence of incidence of the disease on the season of the year, frequency of attacks of the particular areas and their clinical characteristics, aetiology of the inflammation, types of patient complaints, prevalence of current systemic diseases, results of microbiological and selected laboratory analyses, socio-economic status of the patients, and duration of patient stay at the hospital. Statistical analysis was performed by using Pearson’s correlation coefficient, the statistical significance level was p < 0.05. Results: The mean age of the patients was 39.8 years. The group of 195 patients included 108 (55%) males and 87 (45%) females. The mean time between the first symptoms of the disease and admission to the Department was 5 days. From among the 195 patients, 116 (59.5%) were working persons, 79 (40.5%) were non-working (children, students, unemployed persons, women on maternity leave, retired people). The odontogenic origin of the disease was verified in 173 (88.7%) patients. In total, 65 (33.3%) patients had no coinciding complicating systemic disease, 22 (11.3%) patients had diabetes mellitus. The most frequent symptom of cellulitis was painful swelling, found in 194 (99.5%) patients, followed by jaw contracture, found in 153 (78.5%) patients. Conclusion: The results are largely very similar to those of previous studies performed in other countries, except that we found no correlation between the prevalence of cellulitis and the socio-economic status, nor have we confirmed Klebsiella pneumoniae sp. as the cause of cellulitis in patients with diabetes mellitus.

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.

Mycotic Aneurysm of the Common Carotid Artery as a Presenting Symptom for Early Colorectal Malignancy

Mycotic carotid aneurysms are rare vascular conditions that are associated with high mortality if left untreated. We present a gentleman who had a progressively enlarging tender pulsatile swelling on the right side of neck. Emergency computed tomography scan showed a large mycotic aneurysm arising from the right common carotid artery, and he underwent emergency open exploration with interposition bypass graft. Bacteroides fragilis species, which signified gastrointestinal-related sepsis, was isolated from the thrombus culture. Subsequently search of systemic septic source showed an early rectal adenocarcinoma. This is the first case in the world's literature of a patient who had B. fragilis mycotic carotid aneurysm as a presenting complaint of his occult rectal malignancy.

Characteristics of pyogenic odontogenic infection in patients attending Mulago Hospital, Uganda: a cross-sectional study

Background

Predisposing factors of pyogenic odontogenic infection include dental caries, pericoronitis, periodontitis, trauma to the dentition and the supporting structures or complications of dental procedures. The infections are usually polymicrobial involving normal endogenous flora. We characterised pyogenic odontogenic infection in patients attending Mulago Hospital, Uganda.

Results

Of the 130 patients, 62 (47.7%) were female. The most frequently involved fascial spaces were: the buccal, 52 (25.4%); submasseteric, 46 (22.4%) and the submandibular space, 36 (17.5%). Dental caries was the most prevalent predisposing factor, particularly of the lower third molar teeth. Viridans Streptococci Group and Staphylococcus aureus were the most frequent bacterial isolates: 23.5% and 19.4%, respectively. All Viridans Streptococci isolates were resistant to penicillin G, sulfamethoxazole/trimethoprim (cotrimoxazole), ampicillin and tetracycline, but susceptible to vancomycin. All Staphylococcus aureus strains were resistant to cotrimoxazole and ampicillin while retaining susceptibility to vancomycin, cefotaxime, linezolid, moxifloxacin and amoxicillin/clavulanate. Thirty five (26.9%) patients were HIV infected and the HIV status did not significantly influence the pattern of odontogenic infection.

Conclusions

Dental caries was the most prevalent predisposing factor for pyogenic odontogenic infection. High prevalence of bacterial resistance to ampicillin and cotrimoxazole suggests the need for regular antibiotic susceptibility tests of isolates and rational use of antibiotics in the management of these infections. Prevention requires strengthening of oral health in the community.

Antibiotic susceptibility of 33 Prevotella strains isolated from Romanian patients with abscesses in head and neck spaces

The purpose of this study was to investigate the susceptibility of a series of 33 Prevotella strains isolated from patients with abscesses in the head and neck spaces, presented to one Romanian hospital. The Etest was applied to determine the value of the minimum inhibitory concentrations for: penicillin G, ampicillin, amoxicillin-clavulanate, metronidazole and clindamycin. In addition, the beta-lactamase activity was detected by the chromogenic cephalosporin disc method. The results indicated that 11 isolates were resistant to both penicillin G and ampicillin due to the beta-lactamase production. All the 33 Prevotella strains were susceptible to the other 3 antimicrobial agents tested, except for only one penicillin G - ampicillin resistant isolate of Prevotella buccae (MIC > 32 and MIC = 12 mg/L, respectively), which showed high resistance to clindamycin (MIC > 256 mg/L) too. Our data underline the necessity for antimicrobial testing including monitoring of beta-lactamase production in cases of oro-maxillo-facial mixed anaerobic infections where antimicrobial treatment is required in addition to the surgical drainage. The results of the study indicated that amoxicillin-clavulanate, like metronidazole, was fully active against the tested Prevotella strains. However, local and multicentre surveys on drug resistance among the clinically significant anaerobic isolates should be carried out periodically.

Deep neck infections: risk factors for mediastinal extension

The goal of the study was to find out the risk factors for the development of mediastinitis in patients with deep neck infections (DNI) and describe the differences in symptoms and clinical image between uncomplicated DNI and infections with mediastinal spread. Our study represents the retrospective analysis of 634 patients with DNI. The file was divided into two groups. There were 619 patients (97.6%) in the first group who had an uncomplicated course of DNI without spread of infection into mediastinum (DNI group). The second group included 15 patients (2.4%) with descending mediastinitis as a complication of DNI (mediastinitis group). The most frequent comorbidities were cardiac and pulmonary diseases, which were more frequent in the mediastinitis group comparing to DNI group. Dental origin of the infection was more frequent in DNI group than in the mediastinitis group. On the other hand, tonsillar origin of the infection was more frequent in the mediastinitis group than in DNI group. In both mediastinitis and DNI groups, the typical presenting symptoms were pain, oedema and dysphagia. Furthermore, dysphagia, dyspnoea, dysphonia and restriction of neck movements were more significant in the mediastinitis group than in DNI group. The incidence of airway obstruction, sepsis, pneumonia and death was significantly higher in the mediastinitis group than in DNI group. Due to our results, the predisposing factors for mediastinal extension of DNI are cardiovascular and pulmonary diseases. Mediastinitis is associated with higher morbidity and mortality than DNI. The most common complications are airway obstruction, pneumonia and sepsis.

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.

High prevalence and resistance rates to antibiotics in anaerobic bacteria in specimens from patients with chronic balanitis

Aim of the study was to assess both prevalence and antibiotic resistance in anaerobic bacteria from glans penis skin of 70 adults. Strain susceptibility was determined by breakpoint susceptibility test or E test. In 9 asymptomatic, 48 untreated and 13 treated symptomatic patients, anaerobes were found in 22.2%, 70.8% and 53.3%, respectively. Gram-positive strains (GPAs) were 2.2-fold more common than Gram-negative ones. Prevalent Gram-negative (GNAs) and GPAs were Prevotella spp. and anaerobic cocci, respectively. Clostridium difficile strain was found in an untreated patient. In GNAs, resistance rates to amoxicillin, metronidazole, clindamycin, tetracycline, levofloxacin, and amoxicillin/clavulanate were 42.1, 0, 52.6, 53.3, 86.7 and 5.2%, respectively. In GPAs, the resistance rates to metronidazole, clindamycin, tetracycline, levofloxacin and amoxicillin/clavulanate were 18.2, 34.1, 52.6, 36.8 and 0%, respectively. In conclusion, anaerobes were 1.6-fold more frequent in untreated symptomatic patients compared with other patients, suggesting their participation in development of chronic balanitis. GPAs were more common than GNAs. The resistance rates to amoxicillin, clindamycin, tetracycline, and levofloxacin were high. Most active agents were metronidazole and amoxicillin/clavulanate. Resistance in anaerobes varies according to sites of specimens and years of study.

In Vitro Susceptibility Test of Different Clinical Isolates against Ceftriaxone

OBJECTIVES

Because of the prevailing penicillin resistance in microorganisms, broad spectrum cephalosporins are used empirically specially in developing countries. The aim of this study is to determine the susceptibility pattern of different gram positive and gram negative pathogens against third generation cephalosporin-ceftriaxone to explore the existing effectiveness of this antibiotic.

METHODS

180 clinical isolates of different gram positive and gram negative pathogens including P.mirabilis, S. typhi P.aeruginosa, E. coli, S. aureus and Klebsiella were collected from blood and urine samples of in-patients. 30 isolates of all species were tested against each of six brands of ceftriaxone using in vitro sensitivity tests by disc diffusion method (NCCLS criteria). The susceptibility limit was ≥21 mm zone of inhibition, while moderately susceptible was considered at 20-14 mm, and those isolates which showed >13 mm or no zone of inhibition were resistant to this antibacterial drug.

RESULTS

Ceftriaxone was found most effective against S. aureus. While 96.1% of the isolates showed susceptibility towards ceftriaxone, followed by E. coli (95%), P. aeruginosa (92.7%), K. pneumonia (89.4%) and S. typhi (87.2%). P. mirabilis showed lowest susceptibility amongst all the test organisms (83.8%).

CONCLUSION

Ceftriaxone can be used as a drug of choice in infections caused by S. aureus, E. coli, P. aurigenosa, K. pneumonia and S. typhi. However, it should be used with other antimicrobial agents in order to increase its effectiveness against P. mirabilis.

Susceptibility of strict and facultative anaerobes Isolated from endodontic infections to metronidazole and beta-lactams

Endodontic infections are mixed aerobic-anaerobic infections and several microbial groups associated to these pathologies are also involved in orofacial infections. The goal of this study was to evaluate the susceptibility of microorganisms isolated from endodontic infections to beta-lactams and metronidazole and verify the production of beta-lactamases. Clinical specimens were collected from 58 endodontic infections of 52 patients. The microorganisms were isolated in selective and non-selective culture media, under anaerobiosis and aerobiosis, and identified using biochemical methods. In the susceptibility tests, it was used an agar dilution method, and Wilkins-Chalgren agar enriched with blood, hemin and menadione for the anaerobes, while Mueller-Hinton agar was employed for the facultative anaerobes. The production of beta-lactamases was evaluated through the biological and chromogenic cephalosporin methods. All tested isolates were sensitive to imipenem and 99.3% to amoxicillin/clavulanate association, while 16.1% showed resistance to amoxicillin and penicillin G, and 4.89% to cefoxitin. Resistance to metronidazole was just found in facultative anaerobes. Production of beta-lactamases was detected in 18.2% of the isolates and presented a correlation with resistance to beta-lactams.

Eight-year retrospective study of odontogenic origin infections in a postgraduation program on oral and maxillofacial surgery

PURPOSE

Infections are one of the most commonly found conditions in oral and maxillofacial surgery practice. They always represent a risk to patients regardless of whether they are of odontogenic origin or not, and if not treated at an early stage they may rapidly evolve and spread to adjacent anatomical structures, leading to serious complications and, occasionally, to death. For this reason, the objective of this study was to retrospectively analyze data from patients with infections attended by the Department of Oral and Maxillofacial Surgery of the Piracicaba Dental School at the State University of Campinas-Unicamp.

PATIENTS AND METHODS

In accordance with date and inclusion criteria, sampling comprised 210 patient reports from January 1999 to March 2007. Patients' demographic data reviewed were gender, age, signs and symptoms, facial spaces affected, and therapy adopted.

RESULTS

The mean age of patients was 30 years old (SD = 16.6), and the main origin of infections was odontogenic (79.31%); principal signs and symptoms were trismus (43.33%), fever (28.10%), and dysphagia (25.24%). The main facial spaces affected were the buccal mandibular space (50.00%), submandibular space (31.90%), and buccal maxillary space (19.05%). Surgical drainage was carried out in 46.67% of cases, and 10.95% of these interventions were performed under general anesthetic. Only 3 of all patients developed complications.

CONCLUSIONS

Infection patients were basically young adults; no predisposition concerning gender or race was detected. The therapeutic protocol adopted presented very positive results, with a small number of complications.

Antimicrobial resistance and the management of anaerobic infections

Management of anaerobic infections encompasses surgical procedures, antibacterial therapy and adjuncts. At present, metronidazole, penems, beta-lactam/beta-lactamase inhibitor combinations and chloramphenicol have the highest activity against obligate anaerobes. Tigecycline is a promising new agent. Other antibacterials (e.g., nitazoxanide, moxifloxacin, garenoxacin and ramoplanin) and nonantibiotic agents show potential but need further investigation. The patient's characteristics, mixed anaerobic/aerobic infections, infection sites, bacterial resistance patterns, bactericidal activity of agents and their pharmacokinetics, toxicity and influence on the normal flora should be considered. Susceptibility patterns of anaerobes have become less predictable owing to increasing antibacterial resistance. Emergence of highly virulent or multidrug-resistant strains is challenging the current therapy. To counteract these trends, regular resistance surveillance in anaerobes, rational antibiotic use and evaluation of new treatment alternatives are important.