Pathogenesis and Microbiology

Microbiologically, patients suffering from adenoiditis harbor an abnormal NP and oropharyngeal microflora. Typically, this flora is characterized by the persistent presence of two to five bacterial species that are frequently associated with clinical infections of the head and neck GABHS, S. aureus, H. influenzae, Streptococcus pneumoniae, Candida albicans, enteric gramnegative aerobes and AGNB. The viruses often present are adenoviruses and Epstein-Barr virus (85,86). The adenoids are believed...

Abscesses Of The Head And Neck General Considerations

Staphylococcus aureus and Group A beta-hemolytic streptococci (GABHS) were established as the predominant pathogens in abscesses of the head and neck in most studies done until 1970 (1). However, when methodologies suitable for recovery of anaerobic bacteria were used, these organisms were found to predominate especially in infections that originated from sites where these organisms are the predominant flora (i.e., dental, sinus, and tonsillar infections) (2,3). The recovery of anaerobes from...

Role of Beta LactamaseProducing Bacteria

Bacterial resistance to the antibiotics used for the treatment of sinusitis has consistently increased in recent years. Production of the enzyme beta-lactamase is one of the most important mechanisms of penicillin resistance. Several potential aerobic and anaerobic BLPB occur in sinusitis. BLPB have been recovered from over a third of patients with acute and chronic sinusitis (8-11,18). H. influenzae and M. caterrhalis are the predominate BLPB in acute sinusitis (18) and S. aureus, pigmented...

Odontogenic Infections

The complexity of the oral and gingival flora has prevented the clear elucidation of specific etiologic agents in most forms of oral and dental infections. In the gingival crevice, there are approximately 1.8 X1011 anaerobes per gram (1). Because anaerobic bacteria are part of the normal oral flora and outnumber aerobic organisms by a ratio of 1 10 to 1 100 at this site, it is not surprising that they predominant in dental infections. There are at least 350 morphological and biochemically...

Chronic Sinusitis

Symptoms of chronic sinusitis vary considerably. Fever may be absent or be of low grade. Frequently symptoms are protracted and include malaise, easy fatigability, difficulty in mental concentration, anorexia, irregular nasal or postnasal discharge, frequent headaches, and pain or tenderness to palpation over the affected sinus. Plain radiography and especially CT scanning can assist in diagnosing chronic infection and its complications. CT is useful in investigating any anatomical finding that...

Sinusitis

Sinusitis is defined as an inflammation of the mucous membrane lining the paranasal sinuses (Fig. 1). Sinusitis can be classified chronologically into five categories (1) acute exacerbation of chronic sinusitis (AECS). Acute sinusitis is a new infection that may last up to four weeks and can be subdivided symptomatically into severe and non-severe. Recurrent acute sinusitis is diagnosed when four or more episodes of acute sinusitis, which all resolve completely in response to antibiotic...

Chronic Bacterial Sinusitis Antiinflammatories

Long-term, low dose macrolide therapy represents one attempt at controlling the inflammation associated with chronic sinusitis (80). Medicines that have anti-inflammatory properties and are well tolerated are sought to help ease the reliance on systemic corticosteroids that affect both the number and function of inflammatory cells. When used in a topical form, nasal steroid sprays have been shown to be safe and effective in reducing the symptoms of alleric rhinitis (81). Their use in patients...

Adjuvant Therapies Acute Bacterial Sinusitis

Patients with a viral URTI may benefit from symptomatic therapy, aimed at improving their quality of life during the acute illness. The use of normal saline as a spray or lavage can provide symptomatic improvement by liquefying secretions to encourage drainage. The short-term (three days) use of topical alpha-adrenergic decongestants can also provide symptomatic relief, but their use should be restricted to older children and adults due to the potential for undesirable systemic effects in...

Antimicrobial Therapy of Chronic Sinusitis

Many of the pathogens found in chronically inflamed sinuses are resistant to penicillins through the production of beta-lactamase (8-11). These include both aerobic (S. aureus, H. influenzae, and M. catarrhalis) and anaerobic isolates (B. fragilis group and over half of the TABLE 6 Empirical Antimicrobial Therapy in Acute Bacterial Sinusitis Amoxicillin Therapy (high-dose) Mild illness No history of recurrent acute sinusitis During summer months When no recent antimicrobial therapy has been...

Antimicrobial Treatment of Acute Sinusitis

Treatment is aimed at establishing good drainage by using decongestants, nasal saline irrigation spray, humidification, and mucolytic agents. Systemic decongestants or antihistamines may be helpful, especially in allergic individuals. Anatomic deformities should be corrected. Appropriate antibiotic therapy is of paramount importance. Antimicrobial therapy has been shown to be beneficial and effective in preventing septic complications (49,73). Endoscopic examination and culture can assist in...

Bacteriology of Sinusitis of Odontogenic Origin

Odontogenic sinusitis is a well-recognized condition and accounts for approximately 10 to 12 of cases of maxillary sinusitis. Brook (16) studied the microbiology of 20 acutely and 28 chronically infected maxillary sinuses that were associated with odontogenic infection. Polymicrobial infection was very common with 3.4 isolates specimen and 90 of the isolates were anaerobes in both acute and chronic infections. The predominant anaerobic bacteria were AGNB, Peptostreptococcus spp., and...

Bacteriology of Sinusitis in the Immunocompromised Hosts

Sinusitis occurs in a wide range of immunocompromised hosts including neutropenics, diabetics, patients in critical care units, and patients infected with HIV. Fungal and P. aeruginosa are the most common forms of sinusitis in neutropenic patients. Aspergillus spp. is frequently the causative organism, although mucor, rhizopus, alternaria, and other molds have been implicated (50). Fungi and S. aureus, streptococci and gram-negative enterics are the most common isolates in diabetics (51). The...

Bacteriology of Nosocomial Sinusitis

Nosocomial sinusitis often develops in patients who require extended periods of intensive care (postoperative patients, burn victims, and patients with severe trauma) involving prolonged endotracheal or nasogastric intubation. P. aeruginosa and other aerobic and facultative gramnegative rods are common in sinusitis of nosocomial origin (especially in patients who have nasal tubes or catheters), the immunocompromised, patients with human immune deficiency viral infection and patients who suffer...

Bacteriology of Acute Exacerbation of Chronic Sinusitis

Brook et al. evaluated the microbiology of maxillary AECS by performing repeated endoscopic aspirations in seven patients over a period of 125 to 242 days (45). Bacteria were recovered from all aspirates and the number of isolates varied between two and four. The aerobes isolated were H. influenzae, S. pneumoniae, M. catarrhalis, S. aureus, and K. pneumoniae. The anaerobes included pigmented Prevotella and Porphyromonas, Peptostreptococcus, Fusobacterium spp., and Propionibacterium acnes. A...

Bacteriology of Chronic Sinusitis

Although the etiology of the inflammation associated with chronic sinusitis is uncertain, bacteria can be isolated in the sinus cavity in these patients (18,19). Bacteria are believed to play a major role in the etiology and pathogenesis of most cases of chronic sinusitis, and antimicrobials are often prescribed for the treatment of this infection. Numerous studies have examined the bacterial pathogens associated with chronic sinusitis. However, most of these studies did not employ methods that...

Microbiology of Acute Sinusitis

Viral infection (mostly Rhino, influenza, adeno, and para-influenza viruses) is the most common predisposing factor for URTIs, including sinusitis. Viral infection can also concur with the bacterial infection. The mechanism whereby viruses predispose to sinusitis may involve viral-bacterial synergy, induction of local inflammation that blocks the sinus ostia, increase of bacterial attachment to the epithelial cells, and disruption of the local immune defense. The bacteria recovered from...

Cellulitis

GABHS is the major and S. aureus is a minor cause of the classic erysipelas. Streptococci other than group A were isolated in lower extremity cellulitis involved in post-saphenous venectomy (groups C, G, and B) (2) and in neonatal cellulitis. Cellulitis due to Streptococcus pneumoniae through bacteremic route were also described (21). Enterobacteriaceae and fungi (Cryptococcus neoformans) were recovered from cellulitis in the immunocompromised host. E. coli was recovered from children with...

Mixed Infections Involving Anaerobic BLPB

Anaerobic BLPB can be isolated from a variety of infections in adults and children, sometimes as the only isolates and sometimes mixed with other flora (Table 3). Table 4 summarizes our experience in the recovery of these organisms from skin and soft tissue infections (157-166), upper respiratory tract (167-179), lower respiratory tract (180-183), obstetric and gynecologic (184), intra-abdominal (184-186), and miscellaneous infections (187-190). The rate of isolation of these organisms varies...

Complications

Sinus infection when not treated promptly and properly may spread via anastomosing veins or by direct extension to nearby structures (Fig. 5). Orbital complication was categorized by Chandler et al. (67) into five separate stages according to its severity (see chapter 11). Contiguous spread could reach the orbital area, resulting in periorbital cellulitis, subperiosteal abscess, orbital cellulitis, and abscess. Orbital cellulitis may complicate acute ethmoiditis if a thrombophlebitis of the...

Aspiration Pneumonia and Lung Abscess

The aspiration of saliva and oropharyngeal secretions that contain many aerobic and anaerobic bacteria introduces these organisms into the lower respiratory tract (1). A breakdown of the normal host protective mechanisms predisposes to anaerobic infection and is the common denominator of patients who develop this infection. Aspiration of food and vomitus is common in those who are prone to aspirate because of debilitation, dysphagia, alcoholism, nasogastric tube feeding, congenital...

Acute Salpingitis And Pelvic Inflammatory Disease Pathogenesis and Microbiology

PID usually begins with cervical infection that is caused by C. trachomatis, N. gonorrhoeae, or both. Acute salpingitis and PID occur after extension of the infection from the lower parts of the female genital tract to higher structures. Organisms infecting the cervix can spread to involve the uterus and fallopian tubes in two ways by causing a transient endometritis that extends to involve the endosalpinx or by reaching the tubes via lymphatic spread. Acute salpingitis and PID may be...

Acute Otitis Externa Swimmers

External otitis is defined as a varying degree of an inflammation of the auricle, external ear canal, or outer surface of the tympanic membrane (67). The etiology of the inflammation can be an infection, inflammatory dermatoses, trauma, or a combination of these. The clinical infection is divided to be either localized or diffuse, and acute or chronic. Predisposing factors to infection include extraneous trauma, loss of the canal's protective water-repellent coating provided by the cerumen,...

Ear Infections

Otitis media is one of the most common diseases of early childhood. The incidence is highest between 6 and 18 months. There are four defined types of otitis media (1) (z) acute otitis media (AOM) is characterized by a rapid onset of signs and symptoms of middle-ear inflammation. Earache, bulging of the tympanic membrane, and purulent exudate characterize the early phase of infection. Even though clinical signs and symptoms resolve rapidly, the effusion can persist (ii) otitis media with...

BL in Clinical Infections

Several studies demonstrate the activity of the enzyme BL produced by anaerobic bacteria in polymicrobial infections. De Louvois and Hurley (206) demonstrated degradation of penicillin, ampicillin, and cephaloridine by purulent exudates obtained from 4 of 22 patients with abscesses. Studies by Masuda and Tomioka (207) demonstrated BL activity in empyema fluid. Most infections were polymicrobial and involved both K. pneumoniae and P. aeruginosa. The presence of the enzyme BL in clinical...

Studies in Children

Anaerobes were recovered in three studies, the only one that employed methods for their isolation (7,31,32). Brook (7) studied 40 children with chronic sinusitis. The sinuses infected were the maxillary (15 cases), ethmoid (13), and frontal (7). Pansinusitis was present in five patients. A total of 121 isolates (97 anaerobic and 24 aerobic) were recovered. Anaerobes were recovered from all 37 culture-positive specimens, and in 14 cases (38 ) they were mixed with aerobes. The predominant...

Microbiology

Microorganisms usually gain access to burns directly because microbiota are normally present on the skin, and the skin is the interface with the outside world. The source of colonization of the burn wound usually is the patient's own endogenous flora as well as environmental organisms (4). These organisms can reach the wound directly through the skin or the blood stream. Soon after a burn injury, surface cultures may reveal multiple organisms. Within three to five days, the wound will become...

Introduction to Anaerobes

Anaerobic bacteria differ in their pathogenicity. Not all of them are believed to be clinically significant, while others are known to be highly pathogenic. Table 1 lists the major anaerobes that are most frequently encountered clinically. The taxonomy of anaerobic bacteria has changed in recent years because of their improved characterization using genetic studies (1). The ability to differentiate between similar strains enables better characterization of type of infection and predicted...

Pathogenesis

Cholesteatoma that accompanies CSOM induces absorption of the underlying bone, but the mechanism by which this occurs is not well understood. Various theories attempt to explain the possible role of different factors in the process of expansion of the cholesteatoma and the collagen degradation that occurs in its vicinity. The volatile acids produced by anaerobic bacteria may play a role in this process (59). TABLE 4 Recovery of BLPB and free Beta-Lactamase in Chronically Infected Ear Aspirates...

Myositis

Infectious myositis caused by bacteria can invade from contiguous sites such as skin and subcutaneous abscesses, ulcers, penetrating wounds, and osteomyelitis or through hematogenous spread. Trauma is a common cause in children (36,47). Vascular insufficiency in an extremity can also facilitate the process. However, primary muscle abscess can also occur in the absence of a predisposing site of infection (48). No conclusive evidence exists, which relate tropical pyomyositis causality to...

Periodontitis

All forms of periodontitis are polymicrobial aerobic-anaerobic bacterial infection. Periodontal disease develops usually because of two events in the oral cavity an increase in bacterial quantity of AGNB and a change in the balance of bacterial types from harmless to disease-causing bacteria. Among the bacteria most implicated in periodontal disease and bone loss are Actinobacillus actinomycetemcomitans and P. gingivalis. Other bacteria associated with periodontal disease are B. forsythus, T....

Management

The threshold of suspicion for the diagnosis and empiric treatment of PID should be low. Salpingitis and PID are managed primarily with antimicrobial therapy. This can be achieved by penicillin plus probenecid, ampicillin, or tetracycline. In areas where resistance of gonococci to penicillin has been observed, spectinomycin can be used. Surgical intervention may be required if the patient fails to respond to medical therapy. Adolescents are at particularly high risk for future reproductive...

Endometritis and Pyometra

Endometritis and pyometra are seen more commonly in older females who suffer from cervical canal obstruction or carcinoma or following delivery. However, they can also be seen occasionally in adolescent females. Endometritis occurs when bacteria invade the uterine cavity, and pyometra develops when pus is collected within the uterus. Regardless of the etiology, anaerobes are predominant in endometritis and pyometra. Hillier et al. (26) obtained endometrial biopsies for histologic and...

Fusobacterium Species

Cells of Fusobacterium spp. are moderately long and thin with tapered ends and have typical fusiform morphology. The species of Fusobacterium seen most often in clinical infections are Fusobacterium nucleatum, Fusobacterium necrophorum, Fusobacterium mortiferum, and Fusobacterium varium. F. nucleatum is the predominant Fusobacterium from clinical specimens, often associated with infections of the mouth, lung (38,60), and brain (37). They are often isolated from abscesses, obstetrical and...

Classification And Diagnosis Impetigo

Streptococcal impetigo manifests itself as appearance of small vesicles that rapidly pustulate and rupture. After the purulent discharge dries, a golden-yellow crust forms. The lesions remain superficial and do not ulcerate or infiltrate the dermis. Pain and scarring do not occur. The bullous form of impetigo is due to Staphylococcus aureus (phage group II, usually type 71). The initial vesicles turn into fluid bullae that quickly rupture, leaving a moist red surface, which then generates...

Gingivitis And Periodontitis Pathogenesis and Complications

The healthy gingiva is a pink, keratinized mucosa, attached to the teeth and alveolar bone that forms the interdental papilla between the teeth. A 1-2 mm deep crevice of free gingiva surrounds each tooth. The gingival crevice is heavily colonized by anaerobic gram-negative bacilli and spirochetes. Periodontal disease is a term referring to all diseases involving the supportive structures of the teeth (periodontium). It most commonly begins as gingivitis and progresses to period-ontitis. How...

Microbiology Impetigo

Most cases of impetigo and cellulitis are attributed to S. aureus and GABHS alone or in combination (Table 2) (19). A retrospective study investigated both the aerobic and anaerobic Impetigo and cellulitis, diabetic, and chronic skin ulcers Streptococcus group A Staphylococcus aureus Anaerobic oral flora (Prevotella, Fusobacterium, and Peptostreptococcus spp.) around oral area and head and neck Colonic flora Enterobacteriaceae and anaerobes (i.e., Escherichia coli and Bacteroides fragilis...

Conjunctivitis And Dacryocystitis Conjunctivitis

Conjunctivitis in the newborn infant usually is due to chemical and mechanical irritation caused by the instillation of silver nitrate drops or ointment into the eye in order to prevent gonorrheal ophthalmia. Chemical conjunctivitis differs from infective forms in that it becomes apparent almost immediately after the instillation. The most common causes of infectious conjunctivitis in descending order of frequency are Chlamydia trachomatis, Neisseria gonorrhoeae, Staphylococcus spp., inclusion...

Specific Infections Vulvovaginitis

VV is considered to be a disturbance in vaginal flora rather than a true infection (6). Prepubertal females are particularly susceptible to bacterial VV because of anatomic, physiologic, and hygienic considerations (6) including the relative unprotected location of the vaginal introitus and its proximity to the anus, lack of estrogen-induced mucosal cornification, and the neutral to alkaline pH of the vagina (6). Behavioral factors include the tendency of some females to wipe the perineum from...

Carbapenems Imipenem Meropenem and Ertapenem

Imipenem, a thienamycin, is a beta-lactam antibiotic that is effective against a wide variety of aerobic and anaerobic gram-positive and gram-negative organisms including normally multiresistant species such as P. aeruginosa, Serratia spp., Enterobacter spp., Acinetobacter spp., and enterococcus (41,42). It also possesses excellent activity against beta-lactamase-producing Bacteroides. It has the lowest MIC for B. fragilis group and is also most effective against Entero-bacteriaceae. About...

Elimination Of Gabhs

Antimicrobials that are effective against BLPB as well as GABHS have been shown to be effective in the elimination of GABHS in acute and chronic infections or the eradication of GABHS carrier state. These include lincomycin, clindamycin (54-69), penicillin plus rifampin, and the combination of amoxicillin and clavulanic acid (65) (Table 3). Other drugs that may also be effective are the combination of metronidazole and a macrolide. Clindamycin was also found to be superior to penicillin in...

Bacteroides fragilis Group

B. fragilis group is the most prevalent bacteriodaceae isolated. B. fragilis is the most prevalent organism in the B. fragilis group, accounting for 41 to 78 of the isolates of the group. However, it should be remembered that the other members of the group account for the rest of the B. fragilis group isolates. The relative distribution of the different B. fragilis group has important clinical implications in the management of infections involving anaerobic bacteria. This is because of the...

Animal Bites

Almost any aerobic and anaerobic oral flora isolate is a potential pathogen, and therefore the bacteriology of these bite wounds varies and needs individual study (33-38). Holst et al. (14) investigated the distribution of 159 P. multocida isolates from bite wounds. P. multocida accounted for 60 of the isolates and was recovered from all cases of bacteremia. Pasteurella septica, accounted for 13 of isolates, was more commonly isolated from cat than from dog bites and caused more central nervous...

Acute Otitis Media Microbiology

Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are the principal etiologic agents in bacterial AOM accounting for about 80 of the bacterial isolates 2,3 . S. pneumoniae has constantly been found more commonly, irrespective of age group, but its predominance has tended to decrease following the introduction of the pneumococcal conjugate vaccine in 2000 4 , where the frequency of isolation of H. influenzae increased. Of special concern is the increased rate of...

Anaerobes as Part of the Human Indigenous Microbial Flora

The human mucous and epithelial surfaces are colonized with aerobic and anaerobic microorganisms 1 . These surfaces are the skin, conjunctiva, mouth, nose, throat, lower intestinal tract, vagina, and the urethra. The trachea, bronchi, esophagus, stomach, and upper urinary tract are not normally colonized by indigenous flora. However, a limited number of transient organisms may by present at these locations. Differences in the environment, such as oxygen tension and pH and variations in...

Collection Transportation and Processing of Specimens for Culture

Portacul Bacteria Collection

The perception that anaerobes have little or no role in many infections originates from the fact that many past studies did not attempt to identify such a role or used improper methods for collecting specimens for anaerobes. Therefore, carefully assessing studies for methodological properties before judging their ability to determine the role of anaerobes in an infectious process is essential. Multiple examples of differences in the rate of recovery of anaerobic bacteria between studies that...

Clinical Clues to Diagnosis of Anaerobic Infections

Infections caused by anaerobic bacteria are common and may be serious and life-threatening. Anaerobes are the predominant components of the bacterial flora of normal human skin and mucous membranes, and are therefore a common cause of bacterial infections of endogenous origin. Infections due to anaerobic bacteria can evolve all body systems and sites 1 . The predominant ones include abdominal, pelvic, respiratory, and skin and soft tissues infections. Because of their fastidious nature, they...

Virulence of Anaerobic Bacteria and the Role of Capsule

Bacterial Encapsulation

Most anaerobic infections are pyogenic and arise from the normal flora of the skin, oropharynx, the large intestine, or the female genital tract. Such infections typically involve multiple species of bacteria, some strict anaerobes, some strict aerobes and others that are facultative anaerobes i.e., able to grow aerobically or anaerobically . The polymicrobial nature of infections involving anaerobic bacteria is apparent in infections of the respiratory tract, abdomen, pelvis, and soft tissue,...