Bacteriology of human and animal bite wounds

Risk factors associated with infection in patients sustaining dog bites to the face

PURPOSE

The purpose of this study is to identify which patient-level factors, if any, influence the risk of infection following dog bite wounds to the face.

MATERIALS AND METHODS

This retrospective cohort study was conducted using the Kids' Inpatient Database (KID). The primary predictor variable was the type of facial injury. The primary outcome variable was the presence of facial infection. SPSS was used to perform statistical analyses and statistical significance was set at a P-value of < 0.05.

RESULTS

Our final sample comprised a total of 4,420 patients who suffered dog bites to the face, of which 1,237 (28.0%) resulted in infection. Open wound (n = 4,176, 94.5%) was the most common facial injury, followed by bone fractures (n = 105, 2.4%). Relative to children 16-20 years old, children who were 0-5 years old were three times more likely to develop an infection (P < 0.01). Finally, open wounds (P < 0.01) were over seven times more likely to get infected relative to fractures.

CONCLUSIONS

Young children, particularly those below the age of five, are vulnerable to dog bite wounds to the face. Open wounds posed the greatest risk of getting infected.

[Management of the partial avulsions of the auricle]

Injuries of the auricle can range from simple lacerations to complete avulsions. Many techniques of ear replantation have been described in the literature in addition to the type and extent of the involved auricular structures. A direct reattachment of the amputated pinna without microsurgery is rarely successful due to necrosis of the avulsed fragment. Whereas, reconstructions with pocket methods and their variations might lead to better results. In this article we would like to discuss some of these approaches and demonstrate a two-stage reconstruction technique for subtotal avulsion of the auricle.

Algorithmic Approach to Antibiotic Prophylaxis for Traumatic Craniomaxillofacial Injuries

ABSTRACT

Prophylactic antibiotics are commonly used in the management of traumatic injuries to the maxillofacial complex, yet there are no set guidelines for when and when not to prescribe. The purpose of this review is to present the evidence for antibiotic prophylaxis in different clinical scenarios and to propose algorithms to facilitate the decision making process with the ultimate goal of improving antibiotic prescribing practices. A number of databases were searched using a wide range of keywords to ensure the topic was fully encapsulated. The review is divided into 3 sections: soft tissue trauma, maxillofacial fractures, and ballistic injuries. The algorithms were constructed using the current evidence as well as pathophysiologic principles, especially when there were insufficient studies. This review found the literature on antibiotic prophylaxis to be highly varied and not standardized. Creating an algorithm for providers to follow will help to set a standard of care and decrease the misuse of antibiotics.

[Acute Hand Infections - Survey of the Pathogen Spectrum and appropriate Antibiotics]

Acute infections of the hand can be a pathology with severe consequences. Alongside the surgical therapy, it is necessary to establish a systemic antiinfective therapy as well. The most frequent bacteria in acute hand infections are Staphylococcus aureus and, less frequently, different Streptococci. If the infection is the result of a bite wound, the most frequently found bacterium is Pasteurella multocida. Fortunately, the susceptibility to frequently used antibiotics in the (middle-)European area is quite good - according to the literature, resistances are rare. First line antibiotics are 1st and 2nd generation cephalosporins as well as aminopenicillins in combination with beta-lactamase inhibitors. Especially in multi-morbid patients or infections with unusual aetiology, a broader bacterial spectrum is to be expected. It is very effective to collect a tissue sample or swab for microbiological analysis before the establishment of the antiinfective therapy to gain valuable information about the prospective therapy. Ultimately, hand infections are a pathology to be treated with increased attention to avoid severe complications. A close cooperation with the involved specialties and physiotherapists should be sought to guarantee the best possible outcome.

Antibiotic susceptibility of human gut-derived facultative anaerobic bacteria is different under aerobic versus anaerobic test conditions

Facultative anaerobes are the most common cause of infections in anoxic parts of the human body, including deep wound, vagina, periodontal pockets, gastrointestinal tract, genitourinary tract and lungs. Generally, antibiotic susceptibility tests (AST) for facultative anaerobes are performed under aerobic conditions due to ease of handling and rapid growth. However, variation in susceptibility of facultative anaerobes to antibiotics under aerobic and anaerobic conditions can lead to failure of antibiotic treatment. Our study evaluated the susceptibility of facultative anaerobic microorganisms to antibiotics during growth under anaerobic or aerobic conditions. We compared the resistance patterns of representatives from 15 bacterial genera isolated from the human-gastrointestinal tract against 22 different antibiotics from six classes under aerobic and anaerobic conditions. Preliminary results obtained by a disc diffusion method were verified using minimum inhibitory concentration (MIC) testing. The results demonstrated that 7-strains had a similar pattern of drug resistance under both conditions, while the remaining ten strains had significant differences in resistance patterns between aerobic and anaerobic conditions for at least one antibiotic. We conclude that successful antibiotic therapy for host-associated pathogens requires proper assessment of the oxygen condition of the growth environment and MIC testing of each pathogen under anaerobic and aerobic conditions.

Severe purulent pericarditis caused by invasive Eikenella corrodens: case report and literature review

BACKGROUND

Eikenella corrodens is a slowly growing gram-negative bacillus that can cause severe invasive disease in human. Although E. corrodens infections in various sites of human body have been well described, pericarditis caused by invasive E. corrodens has rarely been reported.

CASE PRESENTATION

Here we report the case of a 63-year old male with a complaint of left shoulder pain. The patient was diagnosed as purulent pericarditis by chest computed tomography scan and ultrasound-guided pericardiocentesis, and the pathogen of E. corrodens was identified in the pericardial fluid culture. The clinical condition of the patient deteriorated quickly, and he died right after the drainage surgery even though the pathogen was sensitive to antibiotics treatment.

CONCLUSION

E. corrodens is a rare pericarditis associated pathogen. Purulent pericarditis caused by E. corrodens presents atypical manifestations and rapid progression of infection in immunosuppressed individuals such as neutropenic patients. Earlier diagnosis and proper drainage surgery with effective antibiotics treatment may improve the prognosis.

Infections of the hand: an overview

Infections of the hand are common entities that are frequently encountered by orthopaedic surgeons and primary care physicians.

A high clinical suspicion and a thorough medical history with information about the social and working history of the patients, correct identification of the type and cause of the infection, and prompt initiation of appropriate treatment by the infectious diseases physicians and orthopaedic surgeons are required.

Late diagnosis and inappropriate treatment may be a significant cause of morbidity for the hand and mortality for the patients. This article reviews the clinical spectrum and microbiology of the most common infections of the hand, and discusses the current concepts for their treatment. The aim is to increase the awareness of the treating physicians of the diagnosis and management of infections in the hand.

Cite this article: EFORT Open Rev 2019;4:183-193. DOI: 10.1302/2058-5241.4.180082

Antibiotic resistant zoonotic bacteria in Irrawaddy squirrel (Callosciurus pygerythrus)

Irrawaddy squirrel (Callosciurus pygerythrus) may play an important role in the transmission of zoonotic bacteria, but little is known about the carriage of zoonotic bacteria in this common frugivorous rodent in Bangladesh. We aimed to investigate the presence of common zoonotic bacterial pathogens in Irrawaddy squirrel in the southeast part of Bangladesh. A total of 27 rectal and 27 oro‐nasal swabs were collected from 27 healthy wild Irrawaddy squirrels. Four common zoonotic bacteria were isolated following routine laboratory procedures, and were identified based on colony morphology, and biochemical and staining properties. The pathogenic potential of the identified bacteria was confirmed by detection of virulence genes by PCR. All isolates were subjected to antimicrobial susceptibility test against seven antibiotics from six generic groups which are commonly used in human and veterinary medicine in Bangladesh. The prevalence of Escherichia coli, Salmonella spp., Yersinia spp. and Staphylococcus spp. was 44.4% (95% CI, 32.0–57.6), 13% (95% CI, 6.1–24.7), 44.4% (95% CI, 32.0–57.6), and 72.2% (95% CI, 59.0–82.5), respectively. We identified potential zoonotic virulence genes in all of these four bacterial species. Antimicrobial susceptibility testing revealed the presence of several multidrug resistant bacterial strains in squirrels. To the best of our knowledge, this is the first report in Bangladesh of the detection of antibiotic resistant zoonotic bacteria in Irrawaddy squirrels. The findings underpin the role of Irrawaddy squirrel as a source of pathogenic antibiotic resistant bacteria, consequently, fruit rejected because of squirrel consumption and squirrel‐bites deserve more concern than previously.

Snakebite: When the Human Touch Becomes a Bad Touch

Many issues and complications in treating snakebite are a result of poor human social, economic and clinical intervention and management. As such, there is scope for significant improvements for reducing incidence and increasing patient outcomes. Snakes do not target humans as prey, but as our dwellings and farms expand ever farther and climate change increases snake activity periods, accidental encounters with snakes seeking water and prey increase drastically. Despite its long history, the snakebite crisis is neglected, ignored, underestimated and fundamentally misunderstood. Tens of thousands of lives are lost to snakebites each year and hundreds of thousands of people will survive with some form of permanent damage and reduced work capacity. These numbers are well recognized as being gross underestimations due to poor to non-existent record keeping in some of the most affected areas. These underestimations complicate achieving the proper recognition of snakebite’s socioeconomic impact and thus securing foreign aid to help alleviate this global crisis. Antivenoms are expensive and hospitals are few and far between, leaving people to seek help from traditional healers or use other forms of ineffective treatment. In some cases, cheaper, inappropriately manufactured antivenom from other regions is used despite no evidence for their efficacy, with often robust data demonstrating they are woefully ineffective in neutralizing many venoms for which they are marketed for. Inappropriate first-aid and treatments include cutting the wound, tourniquets, electrical shock, immersion in ice water, and use of ineffective herbal remedies by traditional healers. Even in the developed world, there are fundamental controversies including fasciotomy, pressure bandages, antivenom dosage, premedication such as adrenalin, and lack of antivenom for exotic snakebites in the pet trade. This review explores the myriad of human-origin factors that influence the trajectory of global snakebite causes and treatment failures and illustrate that snakebite is as much a sociological and economic problem as it is a medical one. Reducing the incidence and frequency of such controllable factors are therefore realistic targets to help alleviate the global snakebite burden as incremental improvements across several areas will have a strong cumulative effect.

Comparative In Vitro Activity of Omadacycline against Dog and Cat Bite Wound Isolates

Omadacycline was tested against 125 isolates recovered from infected cat and dog bites in humans. Its activity was similar to that of other compounds in the tetracycline class, and it was active against strains exhibiting tetracycline resistance. Against anaerobic isolates, resistance to tetracyclines was more prominent and omadacycline was the most active of the group. All isolates had omadacycline MICs of <1 μg/ml, with the exception of Eikenella corrodens, which showed reduced susceptibility to the entire tetracycline group.

In Vitro Activities of Pexiganan and 10 Comparator Antimicrobials against 502 Anaerobic Isolates Recovered from Skin and Skin Structure Infections

Pexiganan, a cationic peptide, exhibited a broad range of anti-anaerobic antimicrobial activity. The MIC₉₀s of studied isolates were as follows: Bacteroides fragilis, 16 μg/ml; other B. fragilis group spp., 4 μg/ml; Prevotella and Fusobacterium spp., 32 μg/ml; Porphyromonas spp., 64 μg/ml; Propionibacterium acnes, 4 μg/ml; Eggerthella lenta and Peptostreptococcus anaerobius, 32 μg/ml; other Gram-positive rods and cocci, 4 μg/ml; Clostridium perfringens, 128 μg/ml; and other clostridia, 256 μg/ml. Pexiganan cream shows potential as adjunctive therapy for skin and skin structure infections (SSSIs) involving anaerobes.

In Vitro Activity of Pexiganan and 10 Comparator Antimicrobials against 234 Isolates, Including 93 Pasteurella Species and 50 Anaerobic Bacterial Isolates Recovered from Animal Bite Wounds

Animal bite wounds affect more than 5 million Americans annually, resulting in 300,000 emergency department visits, 10,000 hospitalizations, and an untold number of physician office visits. Various forms of topical therapy are empirically self-employed by many patients prior to seeking medical attention. Pexiganan, a 22-amino-acid synthetic cationic analogue of the peptide magainin II, acts by selectively damaging bacterial cell membranes. We determined the MICs for pexiganan and other antimicrobial agents often used for treatment of bite wounds. Most isolates were from U.S. patients, and ∼10% were from European and Canadian patients. The comparator antimicrobials studied were penicillin, amoxicillin-clavulanate, piperacillin-tazobactam, meropenem, clindamycin, doxycycline, moxifloxacin, ceftriaxone, linezolid, and metronidazole. The MIC₉₀s of pexiganan were 32 μg/ml (against Pasteurella multocida subsp. multocida), 16 μg/ml (P. multocida subsp. septica, Pasteurella canis, and Pasteurella dagmatis), 8 μg/ml (Pasteurella stomatis), 8 μg/ml (Eikenella corrodens), 2 μg/ml (Neisseria weaveri, Neisseria zoodegmatis, and Moraxella canis-Moraxella lacunata group), 16 μg/ml (Bergeyella zoohelcum), 64 μg/ml (Bacteroides pyogenes), 4 μg/ml (Fusobacterium russii), 32 μg/ml (Fusobacterium canifelinum), and 64 μg/ml (Prevotella heparinolytica). The concentration of pexiganan in the cream used was 8,000 μg/ml, more than 60 to 100 times the highest MIC obtained. Pexiganan exhibited a broad range of antimicrobial activity, showing potential for treating animal bite infections. A clinical trial seems warranted.

Clinical Guidelines for the Antibiotic Treatment for Community-Acquired Skin and Soft Tissue Infection

Skin and soft tissue infection (SSTI) is common and important infectious disease. This work represents an update to 2012 Korean guideline for SSTI. The present guideline was developed by the adaptation method. This clinical guideline provides recommendations for the diagnosis and management of SSTI, including impetigo/ecthyma, purulent skin and soft tissue infection, erysipelas and cellulitis, necrotizing fasciitis, pyomyositis, clostridial myonecrosis, and human/animal bite. This guideline targets community-acquired skin and soft tissue infection occurring among adult patients aged 16 years and older. Diabetic foot infection, surgery-related infection, and infections in immunocompromised patients were not included in this guideline.

Camel bite: An uncommon mode of maxillofacial injury, its mechanism and fatality: Case series and review of literature

INTRODUCTION

Maxillofacial injuries are presented with many different patterns. It mostly depends upon the mode of injury like physical assault, road traffic accidents, occupational injuries, fall, sport injuries and animal attacks. Animals bites are common with wild animals but attack from an otherwise calm animal like camel is unusual and unexpected. They may cause a severe kind of maxillofacial injury which ranges from minor lacerations to total loss of soft and hard tissues. Such incidences are frequently seen in Rajasthan, India where camels are kept as a pet. Present study throws light on literature related to animal bite injuries and their management along with our experience with camel bite injuries.

MATERIALS AND METHODS

Twenty patients (19 male and 1 female) of different age groups with variable extent of maxillofacial trauma induced by camel attacks were included in the study. Among them, different patterns of maxillofacial injuries were observed involving both soft and hard tissue.

RESULT AND CONCLUSION

This study provides the comprehensive incidence, pathophysiology, and management of camel inflicted injuries. Understanding the behavior patterns of this animal may prevent such severe injuries.

A wide spectrum of fastidious and ampicillin-susceptible bacteria dominate in animal-caused wounds

The main purpose of this study was to assess the actual occurrence of Gram-negative oxidase-positive bacteria (GNOP) in human wounds caused by animals, mostly cat and dog bites and scratches, and with signs of infection. We report a prospective series of 92 wound samples. Routine culturing was combined with a procedure optimised for fastidious GNOP. All GNOP isolates were identified by 16S rDNA sequencing to the species level. We observed a more prominent role of GNOP, including at least 30 species mostly in the families Flavobacteriaceae, Neisseriaceae and Pasteurellaceae, and less of Staphylococcus aureus and streptococci. The antibiotic susceptibility pattern was investigated, as GNOP are associated with sudden onset of serious infections, making an early decision on antibiotic treatment vital. All GNOP isolates judged to be clinically relevant displayed susceptibility to ampicillin and meropenem, but resistance to oxacillin, clindamycin and gentamicin was frequent. Our findings emphasise the need to cover GNOP as recommended in guidelines, and not only common wound pathogens, when treating an animal-caused wound.

Negative pressure wound therapy for serious dog bites of extremities: a prospective randomized trial

OBJECTIVES

The objectives were to investigate the emergency treatment of serious dog bite lacerations on limbs and to identify whether negative pressure wound therapy (NPWT) was beneficial in these instances.

METHODS

A total of 580 cases with serious limb lacerations due to dog bites were randomly divided into 2 groups. After thorough debridement, the limb lacerations of group A (n = 329) were left open. The remaining cases (n = 251) were randomly divided into 2 subgroups, group B and group C, which were treated with 125 and 75 mm Hg of continuous negative pressure, respectively. Antibiotics were only used in cases where there were systemic signs of wound infection, and were not given prophylactically. The infection rate, infection time, and healing time were analyzed.

RESULTS

The wound infection rates of groups A, B, and C were 9.1%, 4.1%, and 3.9%, respectively. The infection times of the 3 groups were 26.3 ± 11.6, 159.8 ± 13.4, and 166.4 ± 16.2 hours, respectively. The recovery times of the infection patients in the 3 groups were 19.2 ± 4.6, 13.2 ± 2.1, and 12.7 ± 2.3 days, respectively, and in the noninfection patients, the recovery times were 15.6 ± 2.7, 10.1 ± 2.3, and 10.5 ± 1.9 days, respectively. In groups B (-125 mm Hg) and C (-75 mm Hg), the infection rate, infection time, and healing time showed no significant differences.

CONCLUSION

Patients with serious dog bite laceration on limbs could benefit from NPWT. Compared with the traditional treatment of leaving the wounds open, NPWT reduced the infection rate and shortened recovery time. When NPWT was performed, low negative pressure (-75 mm Hg) had the same positive effects as high pressure (-125 mm Hg). Prophylactic antibiotics administration is not recommended for treating this kind of laceration.

LEVEL OF EVIDENCE

Therapeutic/care management, level II.

"Fight-bite": not just a hand problem

Human bite wounds around the knee are rarely seen, yet may require the same urgent attention as a fight bite to the hand. Two cases of polymicrobial septic arthritis of the knee secondary to a human bite wound are described. In both the cases, the diagnosis of the septic arthritis was delayed because the intra-articular wound was unrecognized. The injuries were initially deemed superficial and managed with local wound care. In each case, the knee was flexed at the time of injury and the quadriceps tendon was penetrated by a tooth which inoculated the knee joint. Septic arthritis of the knee presented, in both cases, 72 hours after the injury. These infections proved challenging to treat and required multiple surgeries and prolonged antibiotic therapy. The "fight bite" phenomenon of the hand is widely recognized and the same phenomenon can occur at the knee.

Practice Guidelines for the Diagnosis and Management of Skin and Soft Tissue Infections: 2014 Update by the Infectious Diseases Society of America

A panel of national experts was convened by the Infectious Diseases Society of America (IDSA) to update the 2005 guidelines for the treatment of skin and soft tissue infections (SSTIs). The panel's recommendations were developed to be concordant with the recently published IDSA guidelines for the treatment of methicillin-resistant Staphylococcus aureus infections. The focus of this guideline is the diagnosis and appropriate treatment of diverse SSTIs ranging from minor superficial infections to life-threatening infections such as necrotizing fasciitis. In addition, because of an increasing number of immunocompromised hosts worldwide, the guideline addresses the wide array of SSTIs that occur in this population. These guidelines emphasize the importance of clinical skills in promptly diagnosing SSTIs, identifying the pathogen, and administering effective treatments in a timely fashion.

Bite injuries to the hand: microbiology, virology and management

Bites to the human hand, be it from a pet, a stray animal or even a fellow human, may often have dire consequences for the person suffering the insult. Bites by mammals are a common problem and they account for up to 1% of all visits to hospital emergency rooms, in the UK. Clenched fist injuries to the mouth ('fight bite') are notorious for being the worst human bites. Bite injuries of the hand and their related infections must be monitored vigilantly and managed proactively, by experts in this field of surgery. In this review article we discuss the associated microbiology and virology of these injuries as well as their management.

An analytical study of Mammalian bite wounds requiring inpatient management

BACKGROUND

Mammalian bite injuries create a public health problem because of their frequency, potential severity, and increasing number. Some researchers have performed fragmentary analyses of bite wounds caused by certain mammalian species. However, little practical information is available concerning serious mammalian bite wounds that require hospitalization and intensive wound management. Therefore, the purpose of this study was to perform a general review of serious mammalian bite wounds.

METHODS

We performed a retrospective review of the medical charts of 68 patients who were referred to our plastic surgery department for the treatment of bite wounds between January 2003 and October 2012. The cases were analyzed according to the species, patient demographics, environmental factors, injury characteristics, and clinical course.

RESULTS

Among the 68 cases of mammalian bite injury, 58 (85%) were caused by dogs, 8 by humans, and 2 by cats. Most of those bitten by a human and both of those bitten by cats were male. Only one-third of all the patients were children or adolescents. The most frequent site of injury was the face, with 40 cases, followed by the hand, with 16 cases. Of the 68 patients, 7 were treated with secondary intention healing. Sixty-one patients underwent delayed procedures, including delayed direct closure, skin graft, composite graft, and local flap.

CONCLUSIONS

Based on overall findings from our review of the 68 cases of mammalian bites, we suggest practical guidelines for the management of mammalian bite injuries, which could be useful in the treatment of serious mammalian bite wounds.

Maxillofacial injuries due to animal bites

INTRODUCTION

Animal bites are a significant public health problem, with the majority of bites coming from dogs, cats and humans. These may present as punctures, abrasions, tears, or avulsions. The force and relative bluntness of the teeth also increases the possibility of a crush injury with devitalized tissue .The clinical presentation and appropriate treatment of infected bite wounds vary according to the animal and causative organisms. These wounds have always been considered complex injuries contaminated with a unique polymicrobial inoculum.

MATERIALS

This article reviews animal bite wound incidence, bacteriology, risk factors for complications, evaluation components, recommended treatment and prevention based on advanced PUBMED search of the English language literature from the years 1970 to present.

CONCLUSION

As the bite wounds are frequently located on the face, an oral and maxillofacial surgeon needs to be familiar with the treatment of animal bites, pitfalls in management and to educate patients on ways to avoid future bite injuries. The management of animal bites is an evidence poor area and most recommendations are based on small case series, microbiological data and expert opinion. The main controversies include whether wounds should or should not undergo primary closure and the use of prophylactic antimicrobials.

Hand infections

Many acute hand and upper extremity infections should be treated as surgical emergencies to avoid stiffness, contracture, pain, and amputation. Proper treatment requires understanding of anatomy and how this influences the behavior of certain infections, common offending organisms, antibiotic treatment, management of host factors, and surgical intervention. This article reviews the microbiology, antibiotic coverage, and surgical treatment of the most common infections in the hand: paronychia, felon, herpetic whitlow, flexor tenosynovitis, deep space infections, septic arthritis, bites from humans and animals, necrotizing fasciitis, mycobacterium infections, and fungal infections. Recommendations are based on the most recent available evidence.

Emergency treatment on facial laceration of dog bite wounds with immediate primary closure: a prospective randomized trial study

BACKGROUND

To investigate the emergency treatment on facial laceration of dog bite wounds and identify whether immediate primary closure is feasible.

METHODS

Six hundred cases with facial laceration attacked by dog were divided into two groups randomly and evenly. After thorough debridement, the facial lacerations of group A were left open, while the lacerations of group B were undertaken immediate primary closure. Antibiotics use was administrated only after wound infected, not prophylactically given. The infection rate, infection time and healing time were analyzed.

RESULTS

The infection rate of group A and B was 8.3% and 6.3% respectively (P>0.05); the infection time was 26.3 ± 11.6h and 24.9 ± 13.8h respectively (P>0.05), the healing time was 9.12 ± 1.30 d and 6.57 ± 0.49 d respectively (P<0.05) in taintless cases, 14.24 ± 2.63 d and 10.65 ± 1.69 d respectively (P<0.05) in infected cases.Compared with group A, there was no evident tendency in increasing infection rate (8.3% in group A and 6.3% in group B respectively) and infection period (26.3 ± 11.6h in group A and 24.9 ± 13.8h in group B respectively) in group B. Meanwhile, in group B, the wound healing time was shorter than group A statistically in both taintless cases (9.12 ± 1.30 d in group A and 6.57 ± 0.49 d in group B respectively) and infected cases (14.24 ± 2.63 d in group A and 10.65 ± 1.69 d in group B respectively).

CONCLUSION

The facial laceration of dog bite wounds should be primary closed immediately after formal and thoroughly debridement. And the primary closure would shorten the healing time of the dog bite wounds without increasing the rate and period of infection. There is no potentiality of increasing infection incidence and infection speed, compared immediate primary closure with the wounds left open. On the contrary, primary closure the wounds can promote its primary healing. Prophylactic antibiotics administration was not recommended. and the important facial organ or tissue injuries should be secondary reconditioned.

Ceftaroline versus isolates from animal bite wounds: comparative in vitro activities against 243 isolates, including 156 Pasteurella species isolates

More than 5 million Americans are bitten by animals, usually dogs, annually. Bite patients comprise ∼1% of all patients who visit emergency departments (300,000/year), and approximately 10,000 require hospitalization and intravenous antibiotics. Ceftaroline is the bioactive component of the prodrug ceftaroline fosamil, which is FDA approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs), including those containing methicillin-resistant Staphylococcus aureus (MRSA). There are no in vitro data about the activity of ceftaroline against Pasteurella multocida subsp. multocida and Pasteurella multocida subsp. septica, other Pasteurella spp., or other bite wound isolates. We therefore studied the in vitro activity of ceftaroline against 243 animal bite isolates. MICs were determined using the broth microdilution method according to CLSI guidelines. Comparator drugs included cefazolin, ceftriaxone, ertapenem, ampicillin-sulbactam, azithromycin, doxycycline, and sulfamethoxazole-trimethoprim (SMX-TMP). Ceftaroline was the most active agent against all 5 Pasteurella species, including P. multocida subsp. multocida and P. multocida subsp. septica, with a maximum MIC of ≤0.008 μg/ml; more active than ceftriaxone and ertapenem (MIC(90)s, ≤0.015 μg/ml); and more active than cefazolin (MIC(90), 0.5 μg/ml) doxycycline (MIC(90), 0.125 μg/ml), azithromycin (MIC(90), 0.5 μg/ml), ampicillin-sulbactam (MIC(90), 0.125 μg/ml), and SMX-TMP (MIC(90), 0.125 μg/ml). Ceftaroline was also very active against all S. aureus isolates (MIC(90), 0.125 μg/ml) and other Staphylococcus and Streptococcus species, with a maximum MIC of 0.125 μg/ml against all bite isolates tested. Ceftaroline has potential clinical utility against infections involving P. multocida, other Pasteurella species, and aerobic Gram-positive isolates, including S. aureus.

Anaerobic oral flora in the North American black bear (Ursus americanus) in eastern North Carolina

Microbial flora can provide insight into the ecology and natural history of wildlife in addition to improving understanding of health risks. This study examines the anaerobic oral flora of hunter killed black bears (Ursus americanus) in eastern North Carolina. Oral swabs from the buccal and lingual supragingival tooth surfaces of the first and second mandibular and maxillary molars of 22 black bears were inoculated onto Brucella Blood Agar plates supplemented with hemin and vitamin K after transport from the field using reduced oxoid nutrient broth. Sixteen anaerobic bacterial species, representing nine genera were identified using the RapID ANA II Micromethod Kit system and a number of organisms grown that could not be identified with the system. The most frequently identified anaerobes were Peptostreptococcus prevotii, Streptococcus constellatus, and Porphyromonas gingivalis. The diversity in the anaerobic oral flora of black bear in eastern North Carolina suggests the importance of including these organisms in basic health risk assessment protocols and suggests a potential tool for assessment of bear/habitat interactions.

Hand infections

Hand infections are commonly seen by orthopedic surgeons as well as emergency room and primary care physicians. Identifying the cause of the infection and initiating prompt and appropriate medical or surgical treatment can prevent substantial morbidity. The most common bacteria implicated in hand infections remain Staphylococcus aureus and Streptococcus species. Methicillin-resistant S aureus infections have become prevalent and represent a difficult problem best treated with empiric antibiotic therapy until the organism can be confirmed. Other organisms can be involved in specific situations that will be reviewed. Types of infections include cellulitis, superficial abscesses, deep abscesses, septic arthritis, and osteomyelitis. In recent years, treatment of these infections has become challenging owing to increased virulence of some organisms and drug resistance. Treatment involves a combination of proper antimicrobial therapy, immobilization, edema control, and adequate surgical therapy. Best practice management requires use of appropriate diagnostic tools, understanding by the surgeon of the unique and complex anatomy of the hand, and proper antibiotic selection in consultation with infectious disease specialists.

Microbiology of animal bite wound infections

The microbiology of animal bite wound infections in humans is often polymicrobial, with a broad mixture of aerobic and anaerobic microorganisms. Bacteria recovered from infected bite wounds are most often reflective of the oral flora of the biting animal, which can also be influenced by the microbiome of their ingested prey and other foods. Bacteria may also originate from the victim's own skin or the physical environment at the time of injury. Our review has focused on bite wound infections in humans from dogs, cats, and a variety of other animals such as monkeys, bears, pigs, ferrets, horses, sheep, Tasmanian devils, snakes, Komodo dragons, monitor lizards, iguanas, alligators/crocodiles, rats, guinea pigs, hamsters, prairie dogs, swans, and sharks. The medical literature in this area has been made up mostly of small case series or case reports. Very few studies have been systematic and are often limited to dog or cat bite injuries. Limitations of studies include a lack of established or inconsistent criteria for an infected wound and a failure to utilize optimal techniques in pathogen isolation, especially for anaerobic organisms. There is also a lack of an understanding of the pathogenic significance of all cultured organisms. Gathering information and conducting research in a more systematic and methodical fashion through an organized research network, including zoos, veterinary practices, and rural clinics and hospitals, are needed to better define the microbiology of animal bite wound infections in humans.

Necrotizing fasciitis resulting from human bites: A report of two cases of disease caused by group A streptococcus

Necrotizing fasciitis is a serious and potentially life-threatening condition. Although bite wounds are common, they are not frequently reported as a cause of necrotizing fasciitis. In the present article, two cases of bite-associated necrotizing fasciitis caused by group A streptococcus are reported. Previously published cases are also reviewed.

Cutaneous Mucormycosis Complicating a Polymicrobial Wound Infection Following a Dog Bite

We report a case of cutaneous mucormycosis and Enterobacter infection developing in a 50-year-old diabetic woman following a dog bite that showed delayed development and diagnosis in comparison with typical zygomycotic cutaneous lesions.

Maxillofacial Injuries due to Bear Mauling

Bear bite injuries have become a common occurrence as the forest covers and natural habitats are diminishing. Patients injured in bear attack present with different patterns of injuries. A common protocol may not be suitable for the management of injuries inflicted by these large wild animals. These animals usually attack in remote areas where composite trauma centres do not exist and urgent referrals of these patients will have significant effect on the final outcome. Limited literature is available describing bear bite management in maxillofacial practice. The goal of the present case reports is to document the injuries suffered in bear mauling and to add to the literature on the conservative management with minimal complications.

An unusual mechanism for brain abscess formation in a child

INTRODUCTION

Intracranial infection is an uncommon but serious complication of head injury.

CASE REPORT

This study describes a boy with a traumatic head injury caused by his mother's teeth stemming from a traffic accident, without initial alteration of consciousness or focal neurological signs, who subsequently developed an occipital lobe abscess 3 weeks later. Brain abscess culturing yielded human oral flora. To date, our case is the only report documenting skull fracture with subsequent brain abscess formation caused by human oral flora stemming from traumatic injury from his mother's teeth.

DISCUSSION

A high index of suspicion should be maintained, and early imaging such as computed tomography should be considered for patients with symptoms of intracranial infection or who are at high risk, even after a minor head injury. Early diagnosis, appropriate antibiotic therapy based on knowledge of the causative microbes, and surgery are the major prognostic factors for brain abscess.

[Bite injuries of the hand]

Bite injuries of the hand have a clearly increased risk for infection compared with other regions. Surgical treatment of the wound is indicated, and the debridement must be done thoroughly and with consideration of the wound closure. Antibiotic therapy may be indicated in addition to the surgery if signs of infection exist. Antibiotics alone are not a suitable treatment. Common complications in cases of deficient primary therapy are flexor tenosynovitis, purulent arthritis, and phlegmons of the dorsal hand. These are emergencies and need immediate surgical intervention.

Leptotrichia species in human infections

Leptotrichia species typically colonize the oral cavity and genitourinary tract. These anaerobic bacteria belong to the normal flora of humans and are seldom found in clinically significant specimens. However, on rare occasions, Leptotrichia has been isolated from blood cultures of patients with lesions in the oral mucosa, in particular from patients with neutropenia. These organisms should be considered potential pathogens in neutropenic patients, especially when breaks in the mucosal barriers are present through which they frequently spread to the bloodstream. Leptotrichia has also been recovered from immunocompetent persons, e.g. patients with endocarditis. Although their role in infections remains elusive and not much is known, they have been suggested as emerging pathogens. The present review deals with taxonomy, diagnosis, clinical importance, pathogenesis, host defence, infection control, and spectrum of Leptotrichia infections, and ends with a few typical case reports. Currently, six species have been validly published, but a number of yet uncultivable species exist. Molecular methods recovering uncultivable species should be used to get a real idea of their role as pathogens.

Hand Trauma Pitfalls: A Retrospective Study of Fight Bites

Clench fist or fight bite injuries are associated with some of the worst types of infective complications but their mechanism is often poorly understood. In a retrospective case series, 34 patients seen between 1998 and 2004 presented to a local hand surgery unit with confirmed human bite hand injuries. Seventy-six percent presented with infective complications with a mean delay in presentation of 4 days. Eighty percent of patients were clench fist injuries (CFI) (open joints in 59% and tendon injuries in 63%). Using an aggressive treatment policy including early surgical and antibiotic intervention, most patients achieved good results functionally (full range of movement was achieved in 83% of those with CFI which completed follow-up (44%)). High rates of non-compliance and incomplete follow-up was noted. Major long-term complications including limited range of movement and osteomyelitis was low and suggests the policy of prompt and comprehensive surgical and medical intervention is the optimal treatment option. A brief but in-depth discussion of the specific anatomical pitfalls is included.

Bacteriology of human bite wound infections

This study was designed to define the bacteriology of infected soft-tissue wounds from human bites, and to compare this with the bacteriology of infected animal bites in humans as determined in previous studies. The specimens were collected from 57 patients presenting to emergency rooms at 12 locations around the country. Three hundred and eighty organisms were isolated (224 aerobes and 156 anaerobes), for an average of 6.6 per specimen. The most prevalent anaerobes recovered were Prevotella spp. (34%), while streptococci comprised 44% of all aerobic organisms, over half of which were in the "Streptococcus milleri" group, particularly S. anginosus. The study demonstrated that the pathogens in human bite infections differ considerably from those present in animal bites.

Human bite injury in North East England--the impact of alcohol intake on a mode of violent assault

Ninety-two retrospective cases of human bite injury referred to a Plastic Surgery department are presented. Particular emphasis is placed on the relationship of alcohol intake to these injuries, their distribution and subsequent management. A review of the literature is conducted. The human bite is a leisure time injury of the young single male in the North East. It has been shown that there is a clear link to alcohol and in particular weekend drinking. Prompt operative intervention and wounds located at the head and neck have been shown to be associated with a decreased risk of subsequent infection, which reflects findings in the earlier literature. Fifteen cases were infected. One was the result of a postoperative complication. The remainder were infected on admission. The majority of infected cases were upper limb bites and were associated with a delayed presentation.

Comparison of the epidemiology of human bites evaluated at three US pediatric emergency departments

OBJECTIVES

(1) Using clearly defined methods, provide a current assessment of the epidemiology of human bites sustained by pediatric patients evaluated at a pediatric ED; (2) Compare the frequency, demography, locations, and management of these injuries from the results of the current study to the 2 prior ED studies on pediatric human bites; and (3) Determine if the frequency of these injuries varies by year, gender, or body location.

METHODS

The current study involved a retrospective analysis of all visits to an urban, northeastern, United States pediatric ED from 1995 to 2001. Visits for human bites were identified by International Classification of Disease, Ninth Revision, Clinical Modification codes using 2 separate computerized billing databases. Data were extracted from 2 prior published studies for the comparative portion of the study. Frequency estimates and 95% confidence intervals were created using STATA7.

RESULTS

For the current study, there were 115 visits for human bites, which comprised 0.04% [0.03-0.05] of total visits to this pediatric ED. Bite visits as a percentage of pediatric ED visits remained the same during the 7 years of the current study. For all 3 pediatric EDs, human bites consisted of much less than 1% of the overall patient volume. The majority (65% [55.8-73.9]) of the patients in the current study were male. When adjusted for the frequency of all patient visits by gender, there was no statistically significant difference in percentage of visits for human bites between males and females (0.05% [0.039-0.063] vs. 0.03% [0.023-0.044]) in the current study. Prior studies did not reveal a statistically significant predominance of males presenting for human bites. As a percentage of visits by age group, human bites were more frequent among adolescents in the current study. Altercations and child play were reported approximately equally as the circumstances contributing to the bites in the current study, although altercations were reported more often in older age groups. In all 3 studies, fewer than 14% of patients were admitted and over 80% presented within 12 or 24 hours after the bite.

CONCLUSIONS

Pediatric ED visits for human bites are infrequent and from the current study data, the frequency of visits for these injuries appears to be currently stable. Altercations may not be the main circumstances surrounding all pediatric human bites, yet altercations and human bites might be jointly associated with adolescence. The current study results suggest that most pediatric ED human bite patients are male, although males may not necessarily sustain human bites more frequently than females. Visits for human bite injuries may increase in frequency with age, in comparison to visits for other medical conditions.

Management of human and animal bite wounds: an overview

Serious infections can result from wounds that are caused by bites from animals and humans. Organisms recovered from bite wounds generally originate from the oral cavity of the biting animal, as well as from the patient's skin flora. Anaerobes have been isolated from animal and human bite wound infections, especially those associated with abscess formation. In addition to local wound infections, common complications, such as lymphangitis, septic arthritis, tenosynovitis, and osteomyelitis, and uncommon complications, such as endocarditis, meningitis, brain abscess, and sepsis, may occur. Wound management includes proper local care and, when needed, antimicrobial therapy.