The development of penicillin-resistant oral streptococci after repeated penicillin prophylaxis

Antibiotic resistance of the bacterial spectrum of deep space head and neck infections in oral and maxillofacial surgery - a retrospective study

OBJECTIVES

The aim of this study was to evaluate the current resistance situation concerning routinely used antibiotics for treatment in odontogenic abscesses.

MATERIALS AND METHODS

This retrospective study assessed patients with deep space head and neck infections who were treated by surgical intervention under general anesthesia at our department. The target parameter was the ascertainment of the resistance rates in order to identify the bacterial spectrum, sites in the body, length of inpatient stay, and the age and sex of the patients.

RESULTS

A total of 539 patients, 268 (49.7%) males and 271 (50.3%) females were included in the study. The mean age was 36.5 ± 22.1 years. There was no significant difference between the two sexes with regard to the mean duration of hospitalization (p = 0.574). The predominant bacteria in the aerobic spectrum were streptococci of the viridans group and staphylococci, in the anaerobic spectrum Prevotella and Propionibacteria spp. Rates of resistance to clindamycin were between 34 and 47% in both the facultative and obligate anaerobic spectrum. Increased resistance was likewise found in the facultative anaerobic spectrum, with 94% resistance to ampicillin and 45% to erythromycin.

CONCLUSION

Due to the increasing levels of resistance to clindamycin, their use in empiric antibiotic treatment for deep space head and neck infections should be viewed critically.

CLINICAL RELEVANCE

Resistance rates continue to increase compared to previous studies. The use of these antibiotic groups in patients with a penicillin allergy needs to be called into question and alternative medications sought.

Efficacy of Antibiotic Prophylactic Regimens for the Prevention of Bacterial Endocarditis of Oral Origin

Despite the controversy about the risk of individuals developing bacterial endocarditis of oral origin, numerous Expert Committees in different countries continue to publish prophylactic regimens for the prevention of bacterial endocarditis secondary to dental procedures. In this paper, we analyze the efficacy of antibiotic prophylaxis in the prevention of bacteremia following dental manipulations and in the prevention of bacterial endocarditis (in both animal models and human studies). Antibiotic prophylaxis guidelines remain consensus-based, and there is scientific evidence of the efficacy of amoxicillin in the prevention of bacteremia following dental procedures, although the results reported do not confirm the efficacy of other recommended antibiotics. The majority of studies on experimental models of bacterial endocarditis have verified the efficacy of antibiotics administered after the induction of bacteremia, confirming the efficacy of antibiotic prophylaxis in later stages in the development of bacterial endocarditis. There is no scientific evidence that prophylaxis with penicillin is effective in reducing bacterial endocarditis secondary to dental procedures in patients considered to be "at risk". It has been suggested that there is a high risk of severe allergic reactions secondary to prophylactically administered penicillins, but, in reality, very few cases have been reported in the literature. It has been demonstrated that antibiotic prophylaxis could contribute to the development of bacterial resistance, but only after the administration of several consecutive doses. Future research on bacterial endocarditis prophylactic protocols should involve the re-evaluation of the time and route of administration of antibiotic prophylaxis, and a search for alternative antimicrobials.

Orofacial space infection due to faulty prosthesis

Orofacial space infections are commonly treated by oral and maxillofacial surgeons, even in the post antibiotic era. Pre existing systemic conditions such as diabetes mellitus makes a person more vulnerable to space infection. A prosthesis which is poorly designed often jeopardises the oral health and makes a person susceptible to ulcers of mucosa, which can result in necrosis of mucosa. The sequel of such ulcerations and necrosis would be life threatening Orofacial space infections in medically compromised patients. Here we present a case report of 64 year old diabetic patient presenting with Orofacial space infection as a sequel to necrosis of mucosa caused due to physical and chemical injury by a faulty prosthesis fabricated by a quack practicing dentistry. Submandibular, sublingual and pterygomandibular space were involved leading to trismus and swelling. On forceful mouth opening after extraoral mandibular nerve block, denudation of mucosa was seen distal and lingual to mandibular right second premolar with pus discharge. Radiographic examination revealed no abnormal findings in teeth or bone. The spaces were explored from the opening created by denuded mucosa. Infection control and diabetic control was achieved with antibiotics and oral hypoglycaemic drugs. Patient responded well for the treatment and recovered uneventfully.

Antibiotic susceptibility and resistance of the odontogenic microbiological spectrum and its clinical impact on severe deep space head and neck infections

OBJECTIVE

The purpose of this retrospective study was to identify the major pathogens responsible for deep space head and neck infections and their current resistance to routinely used antibiotics in a university hospital setting.

STUDY DESIGN

A total of 206 patients suffering from odontogenic deep space infections were treated at our department by means of surgical intervention and intravenous administration of antibiotics.

RESULTS

The predominant bacteria were viridans group streptococci (VGS), staphylococci, Prevotella, Peptostreptococcus, and Bacteroides. In the aerobic spectrum, resistance against clindamycin was found in 18%, against macrolides in 14%, and against penicillin G in 7%. The anaerobes were resistant to clindamycin in 11%, to metronidazole in 6%, and to penicillin G in 8%.

CONCLUSION

The high resistance rate for clindamycin and macrolides was especially striking and may necessitate an adaptation of our antibiotic regime in the future.

[Bacterial spectra and antibiotics in odontogenic infections. Renaissance of the penicillins?]

BACKGROUND

The role played by odontogenic infection in dental, oral, and maxillofacial surgery is not to be underestimated even at the present time. An extensive, standardized, prospective study was performed with the intention of verifying the bacterial spectrum of odontogenic infections to evaluate antibiotic sensitivity.

MATERIAL AND METHODS

Bacterial spectra and resistograms of 65 patients with an odontogenic infection were analyzed in a prospective study under standardized conditions for specimen collection and transport.

RESULTS

A total of 226 bacterial strains were analyzed. The ratio between anaerobes and aerobes was approximately 2:1. The most frequent aerobes were members of the genera Streptococcus (46 isolates), Staphylococcus (10 isolates), and Neisseria (9 isolates), respectively. The anaerobic gram-positive spectrum was dominated by members of the genera Eubacterium (19 isolates), Peptostreptococcus (16 isolates), and Actinomyces (12 isolates). The most frequently isolated gram-negative anaerobes were Prevotella (46 isolates), and Fusobacterium (21 isolates). The overall resistance to antibiotics was very low: only 7.3% of all bacteria were resistant to penicillin G/V, and 8.8% showed resistance to ampicillin. The resistance rates to other beta-lactam antibiotics were 4.4% to piperacillin and 0.6% to imipenem, respectively. Penicillin G presented the highest antimicrobial activity among aerobes: only 4.5% of anaerobic strains were resistant of penicillin G. The other resistance rates of anaerobic bacteria to antibiotics were as follows: ampicillin 24%, doxycycline 34%, erythromycin 18%, and clindamycin 9.3%. Penicillin G was also highly antimicrobially active to anaerobes. The resistance rates were: penicillin G 8.1%, ampicillin 2.6%, doxycycline 9.2%, erythromycin 10.2%, and clindamycin 1.4%, respectively.

An outcome audit of the treatment of acute dentoalveolar infection: impact of penicillin resistance

OBJECTIVES

The aim of this audit was to measure the outcome of treatment of acute dentoalveolar infection and to determine if this was influenced by choice of antibiotic therapy or the presence of penicillin-resistance.

SUBJECTS AND METHODS

A total of 112 patients with dentoalveolar infection were included in the audit. All patients underwent drainage, either incisional (n=105) or opening of the pulp chamber (n=7) supplemented with antibiotic therapy. A pus specimen was obtained from each patient for culture and susceptibility. Clinical signs and symptoms were recorded at the time of first presentation and re-evaluated after 48 or 72 h.

RESULTS

A total of 104 (99%) of the patients who underwent incisional drainage exhibited improvement after 72 h. Signs and symptoms also improved in five of the seven patients who underwent drainage by opening of the root canal although the degree of improvement was less than that achieved by incisional drainage. Penicillin-resistant bacteria were found in 42 (38%) of the 112 patients in this study. Of the 65 patients who were given penicillin, 28 had penicillin-resistant bacteria. There was no statistical difference in the clinical outcome with regard to the antibiotic prescribed and the presence of penicillin-resistant bacteria. Strains of penicillin-resistant bacteria were isolated more frequently in patients who had previously received penicillin (p<0.05).

CONCLUSION

Incisional drainage appeared to produce a more rapid improvement compared to drainage by opening of the root canal. The presence of penicillin-resistant bacteria did not adversely affect the outcome of treatment. The observations made support surgical drainage as the first principle of management and question the value of prescribing penicillin as part of treatment.

Comparison of lysis filtration and an automated blood culture system (BACTEC) for detection, quantification, and identification of odontogenic bacteremia in children

Lysis filtration (LyF) was compared with BACTEC PAEDS PLUS in estimating the prevalence of, and sensitivity for, detection of odontogenic bacteremia. Both real bacteremia and simulated bacteremia (seeded blood or saline samples) were assessed to determine the validity of LyF in estimating bacteremia. The simulated bacteremia was also used to assess the reliability of LyF to estimate intensity of bacteremia in CFU per milliliter of blood. Reference organisms were used to assess the abilities of LyF and BACTEC to isolate known oral streptococci. There was no difference in the number of CFU per milliliter of seeded saline, seeded blood, and drop cultures of the organisms plated directly onto agar. Blood cell volume had a negligible effect on the yield of organisms for simulated bacteremia. When LyF and BACTEC were compared, the time to detection of bacteremia was always significantly shorter for BACTEC. For aerobic cultures, these times were 43.7 and 9.6 h, respectively (P < 0.01). For anaerobic cultures, these times were 45.1 and 9.9 h, respectively (P < 0.01). These differences occurred as well for bacteremia following the extraction of a single tooth, with LyF and BACTEC aerobic cultures taking 78 and 30.5 h, respectively (P < 0.0001). For anaerobic cultures, the times were 90.8 and 45 h, respectively (P < 0.0004). A preextraction bacteremia was detected on 2.1% of occasions with BACTEC compared to 31% of occasions with LyF (P < 0.05) The use of LyF was an effective and reliable means of estimating the intensity of pre- and postextraction bacteremia. The values were 3.6 and 5.9 CFU/ml, respectively (P < 0.4729), and the difference was not statistically significant. In summary, BACTEC is quicker than LyF, but less sensitive. LyF provides additional important information in estimating the intensity of bacteremia.

Decision-making on the use of antimicrobial prophylaxis for dental procedures: a survey of infectious disease consultants and review

There is debate concerning use of antibiotic prophylaxis before invasive dental procedures for patients at risk of acquiring distant site infection (DSI). We determined the opinions and practices of infectious disease consultants (IDCs) regarding antimicrobial prophylaxis to prevent DSIs that result from invasive dental procedures by conducting a survey of the 797 members of the Infectious Diseases Society of America Emerging Infections Network (477 members [60%] responded). Ninety percent of respondents closely follow the American Heart Association guidelines for antibiotic prophylaxis for patients with valvular heart disease who undergo invasive dental procedures. In contrast, few IDCs recommend prophylaxis for patients with lupus erythematosus, poorly controlled diabetes mellitus, dialysis catheters or shunts, cardiac pacemakers, or ventriculoperitoneal shunts. Twenty-five percent to forty percent of respondents recommended prophylaxis for prosthetic vascular grafts, orthopedic implants, or chemotherapy-induced neutropenia. We conclude that IDCs differ considerably in their assessment of the need for prophylaxis for patients who have noncardiac risk factors for DSI. These differences underscore the need for definitive studies to delineate appropriate candidates for antimicrobial prophylaxis in dental practice.

An update on the controversies in bacterial endocarditis of oral origin

OBJECTIVES

The aim of this review was to evaluate the evidence implicating dental procedures in bacterial endocarditis (BE) development and the basis for antimicrobial prophylaxis (AP).

STUDY DESIGN

In this article, the literature is reviewed and meaningful findings about epidemiology, pathogenesis, and AP guidelines for BE of oral origin are highlighted. Available results are used to formulate clinical recommendations for the dental practitioner.

RESULTS

The nature of dental procedures that cause bacteremia, patients at risk for BE, and the effectiveness of AP guidelines, continue to be points of controversy. There appears to be further evidence to support the important role of oral health status in the prevention of BE of dental origin.

CONCLUSIONS

One objective of the dental practitioner in caring for patients at risk for BE should be to promote oral health care. There are no hard data on which to scientifically base the need for AP in patients at risk for BE. However, it would appear prudent, at least from the medicolegal perspective, to provide AP, at least to persons with previous BE or prosthetic heart valves and to those undergoing oral surgery, periodontal treatment, or implant placement.

Bacteriologic features and antimicrobial susceptibility in isolates from orofacial odontogenic infections

OBJECTIVE

The aim of this study was to obtain information for an effective antimicrobial therapy against orofacial odontogenic infections; such information was obtained from recent bacteriologic features and antimicrobial susceptibility data.

STUDY DESIGN

The bacteriology and antimicrobial susceptibility of major pathogens in 163 patients with orofacial odontogenic infections to 7 antibiotics was examined.

RESULTS

Mixed infection of strict anaerobes with facultative anaerobes (especially viridans streptococci) was observed most often in dentoalveolar infections, periodontitis, and pericoronitis. Penicillin (penicillin G) was effective against almost all pathogens, although it did not work well against beta-lactamase-positive Prevotella. Cefmetazole was effective against all test pathogens. Erythromycin was ineffective against viridans streptococci and most Fusobacterium. Clindamycin exerted a strong antimicrobial activity on anaerobes. Minocycline was effective against almost all the test pathogens. The antimicrobial activity of levofloxacin against viridans streptococci was not strong.

CONCLUSIONS

An antibiotic that carries out antimicrobial activity against both viridans streptococci and oral anaerobes should be suitable for treatment of dentoalveolar infection, periodontitis, and pericoronitis. Penicillin remains effective as an antimicrobial against most major pathogens in orofacial odontogenic infections. Cefmetazole, clindamycin, and minocycline may be effective against most pathogens, including penicillin-unsusceptible bacteria.

Past administration of beta-lactam antibiotics and increase in the emergence of beta-lactamase-producing bacteria in patients with orofacial odontogenic infections

OBJECTIVE

The purpose of this study was to determine the current status of beta-lactamase-producing bacteria in orofacial odontogenic infections.

STUDY DESIGN

Microbiologic data regarding purulent exudate from 111 cases with orofacial odontogenic infections were analyzed in relation to the past administration of beta-lactams.

RESULTS

beta-lactamase-producing bacteria were isolated more frequently from the beta-lactam-administered group (38.5%) than from the beta-lactam-nonadministered group (10.9%; P <.005), and they were isolated more frequently as the duration of administration increased. The predominant bacteria isolated included Prevotella (the most frequent isolate), viridans streptococci, Peptostreptococcus, and Fusobacterium, and 7.1% of total isolates produced beta-lactamase. Penicillin and cefazolin worked well with beta-lactamase-nonproducing Prevotella but were remarkably affected by beta-lactamase-producing Prevotella. Cefmetazole, sulbactam/cefoperazone, and imipenem worked well against both types of Prevotella.

CONCLUSIONS

beta-lactams are still suitable for the first antimicrobial therapy in the treatment of these infections. However, because past beta-lactam administration increases the emergence of beta-lactamase-producing bacteria, beta-lactamase-stable antibiotics should be prescribed to patients with unresolved infections who have received beta-lactams.

Composition of the oral streptococcal flora in healthy children

OBJECTIVES

To identify the predominant streptococcal species in the mouths of healthy children and to investigate the composition of the oral streptococcal flora over a period of 4 months.

PATIENTS AND METHODS

The subjects were 33 fit, healthy schoolchildren aged between 5 and 16 years. These children were part of a large study and were the matched controls for a group of subjects undergoing bone marrow transplantation. The oral flora was sampled using an oral rinse technique on two separate occasions 4 months apart. The outcome measures were the number of each streptococcal species per millilitre of oral rinse; the isolation frequency of each species; the proportion of each species as a percentage of both the total streptococcal count and the total anaerobic count.

RESULTS

The predominant species were Streptococcus salivarius, S. oralis and S. mitis. There was no significant variation in the composition of the oral streptococcal flora over the 4 month period.

CONCLUSIONS

The oral rinse technique provides a reliable method of sampling the streptococcal flora of children.

Is antibiotic prophylaxis required for endodontic treatment?

The stable prevalence of infective endocarditis since the advent of antibiotic prophylaxis for patients at-risk reflects the increasing polymicrobial etiology of such infections not associated with dental procedures. In addition to concerns for the growing crisis for antibiotic-resistant bacteria, the need for controlled clinical trials to determine the continued efficacy of prophylactic regimens for endodontic and other dental procedures cannot be overstated.