Involvement of Fusobacterium nucleatum in malignancies except for colorectal cancer: A literature review

Fusobacterium nucleatum (F. nucleatum) is originally an oral opportunistic pathogen and accumulating evidence links the presence of F. nucleatum with the pathogenicity, development, and prognosis of colorectal cancer (CRC). However, only limited preliminary data is available dealing with the role of F. nucleatum in other malignancies except for CRC. The present review aims to update and systematize the latest information about the mechanisms of F. nucleatum-mediating carcinogenesis, together with the detection rates, clinicopathological, and molecular features in F. nucleatum-associated malignancies. Comparing with adjacent non-tumorous tissue, previous studies have shown an overabundance of intratumoural F. nucleatum. Although the prognostic role of F. nucleatum is still controversial, a higher prevalence of F. nucleatum was usually associated with a more advanced tumor stage and a worse overall survival. Preliminary evidence have shown that epithelial-to-mesenchymal transition (EMT) and relevant inflammation and immune response aroused by F. nucleatum may be the probable link between F. nucleatum infection and the initiation of oral/head and neck cancer. Further studies are needed to elucidate the etiologic role of the specific microbiota and the connection between the extent of periodontitis and carcinogenesis in different tumor types. The mechanisms of how the antibiotics exerts the critical role in the carcinogenesis and antitumor effects in malignancies other than CRC need to be further explored.

Fusobacterium nucleatum colonization is associated with decreased survival of helicobacter pylori-positive gastric cancer patients

BACKGROUND

An increased amount of Fusobacterium nucleatum (F. nucleatum) is frequently detected in the gastric cancer-associated microbiota of the Taiwanese population. F. nucleatum is known to exert cytotoxic effects and play a role in the progression of colorectal cancer, though the impact of F. nucleatum colonization on gastric cancer cells and patient prognosis has not yet been examined.

AIM

To identify F. nucleatum-dependent molecular pathways in gastric cancer cells and to determine the impact of F. nucleatum on survival in gastric cancer.

METHODS

Coculture of F. nucleatum with a gastric cancer cell line was performed, and changes in gene expression were investigated. Genes with significant changes in expression were identified by RNA sequencing. Pathway analysis was carried out to determine deregulated cellular functions. A cohort of gastric cancer patients undergoing gastrectomy was recruited, and nested polymerase chain reaction was performed to detect the presence of F. nucleatum in resected cancer tissues. Statistical analysis was performed to determine whether F. nucleatum colonization affects patient survival.

RESULTS

RNA sequencing and subsequent pathway analysis revealed a drastic interferon response induced by a high colonization load. This response peaked within 24 h and subsided after 72 h of incubation. In contrast, deregulation of actin and its regulators was observed during prolonged incubation under a low colonization load, likely altering the mobility of gastric cancer cells. According to the clinical specimen analysis, approximately one-third of the gastric cancer patients were positive for F. nucleatum, and statistical analysis indicated that the risk for colonization increases in late-stage cancer patients. Survival analysis demonstrated that F. nucleatum colonization was associated with poorer outcomes among patients also positive for Helicobacter pylori (H. pylori).

CONCLUSION

F. nucleatum colonization leads to deregulation of actin dynamics and likely changes cancer cell mobility. Cohort analysis demonstrated that F. nucleatum colonization leads to poorer prognosis in H. pylori-positive patients with late-stage gastric cancer. Hence, combined colonization of F. nucleatum and H. pylori is a predictive biomarker for poorer survival in late-stage gastric cancer patients treated with gastrectomy.

[A 'Trivial' Angina with Serious Consequences]

A 'Trivial' Angina with Serious Consequences Abstract. A 21-year old man presented with a septic shock two weeks after a pharyngitis. A thrombosis oft the internal jugular vein, septic systemic metastatic lesions and bacteriamia with Fusobacterium necrophorum led to the diagnosis of a Lemierre's syndrome - a rare complication of a pharyngitis with high morbidity and mortality, defined by a septic thrombophlebitis of the internal jugular vein with high risk of embolisation. A streptococcal-negative pharyngitis with red flags should therefore also be treated with antibiotics.

Fusobacterium nucleatum transports noninvasive Streptococcus cristatus into human epithelial cells

Analysis of human buccal epithelial cells frequently reveals an intracellular polymicrobial consortium of bacteria. Although several oral bacteria have been demonstrated to invade cultured epithelial cells, several others appear unable to internalize. We hypothesized that normally noninvasive bacteria may gain entry into epithelial cells via adhesion to invasive bacteria. Fusobacterium nucleatum is capable of binding to and invading oral epithelial cells. By contrast, Streptococcus cristatus binds weakly to host cells and is not internalized. F. nucleatum and S. cristatus coaggregate strongly via an arginine-sensitive interaction. Coincubation of KB or TERT-2 epithelial cells with equal numbers of F. nucleatum and S. cristatus bacteria led to significantly increased numbers of adherent and internalized streptococci. F. nucleatum also promoted invasion of KB cells by other oral streptococci and Actinomyces naeslundii. Dissection of fusobacterial or streptococcal adhesive interactions by using sugars, amino acids, or antibodies demonstrated that this phenomenon is due to direct attachment of S. cristatus to adherent and invading F. nucleatum. Inhibition of F. nucleatum host cell attachment and invasion with galactose, or fusobacterial-streptococcal coaggregation by the arginine homologue l-canavanine, abrogated the increased S. cristatus adhesion to, and invasion of, host cells. In addition, polyclonal antibodies to F. nucleatum, which inhibited fusobacterial attachment to both KB cells and S. cristatus, significantly decreased invasion by both species. Similar decreases were obtained when epithelial cells were pretreated with cytochalasin D, staurosporine, or cycloheximide. These studies indicate that F. nucleatum may facilitate the colonization of epithelial cells by bacteria unable to adhere or invade directly.

Lemierre's and Lemierre's-like syndromes in children: survival and thromboembolic outcomes

OBJECTIVE

Lemierre's syndrome, or jugular vein thrombosis (JVT) associated with anaerobic infection of the head and neck and frequently complicated by septic pulmonary embolism (PE), has historically been described as a disease of young adults. In recent years, an increasing number of case reports of childhood Lemierre's syndrome have been published, focusing mostly on the clinical and laboratory findings at disease presentation and the outcomes of infection. Given the potentially life-threatening thromboembolic complications of this disorder, we reviewed our single-institutional experience with pediatric Lemierre's and Lemierre's-like syndromes (LALLS) from within the context of a larger cohort study of thrombosis in children.

METHODS

Children who were aged from birth to 21 years and had received a diagnosis of JVT and Lemierre's syndrome at the Children's Hospital (Denver, CO) between 2001 and 2005 were identified for inclusion. Case designation of LALLS required all the following: (1) radiologic confirmation of JVT, (2) clinical diagnosis of pharyngitis or other febrile illness, and (3) intraoperative evidence of loculated infection in the head and neck region or radiologic demonstration of bilateral pulmonary infiltrates. Isolation of a causative organism by microbiologic culture of blood, tissue, or purulent fluid was also a necessary diagnostic criterion among patients who had not been treated with antibiotics before culture. A designation of classic Lemierre's syndrome was reserved for documented cases of anaerobic infection. Children in whom JVT was associated with the presence of an ipsilateral central venous catheter were excluded from the analysis. Analysis included information on underlying medical conditions, microbiologic and radiologic findings, and comprehensive hypercoagulability testing results from the time of diagnosis, as well as antimicrobial and anticoagulant therapies administered. In addition, clinical outcomes were evaluated via serial follow-up and included bleeding complications, thrombus resolution on serial radiologic studies, symptomatic recurrent venous thromboembolism (VTE), and mortality.

RESULTS

From January 2001 to January 2005, 9 children with LALLS were identified. Median age was 15 years (range: 2.5-20 years). Clinical presentation was consistent with septic PE in 5 cases and septic shock in 2. Thrombophilia was present in 100% (7 of 7) of children tested, consisting principally of antiphospholipid antibodies and elevated factor VIII activity. Anticoagulation was given in 89% (8 of 9), for a median duration of 3 months (range: 7 weeks-1 year). After a median follow-up time of 1 year, all children had survived without recurrent VTE or anticoagulant-associated major hemorrhage. JVT failed to resolve at 3 to 6 months in 38% of anticoagulated children.

CONCLUSIONS

Our experience suggests that LALLS is an emerging pediatric concern with serious acute (eg, septic PE) and chronic (eg, persistent vascular occlusion) complications. Septic JVT may not be uniquely anaerobic, and the inflammatory prothrombotic state is often characterized by antiphospholipid antibodies and elevated factor VIII levels. Early diagnosis and aggressive antimicrobial and antithrombotic therapies in LALLS may be necessary for optimal long-term outcomes.

Efficient gene transfer and targeted mutagenesis in Fusobacterium nucleatum

Fusobacterium nucleatum is a Gram-negative anaerobe important in dental biofilm ecology and infectious diseases with significant societal impact. The lack of efficient genetic systems has hampered molecular analyses in this microorganism. We previously reported construction of a shuttle plasmid, pHS17, using the native fusobacterial plasmid pFN1 and an erythromycin resistance cassette. However, the host range of pHS17 was restricted to F. nucleatum, ATCC 10953, and the transformation efficiency was limited. This study was undertaken to improve genetic systems for molecular analysis in F. nucleatum. We identified a second F. nucleatum strain, ATCC 23726, which is transformed with improved efficiency compared to ATCC 10953. Two novel second generation pFN1-based shuttle plasmids, pHS23 and pHS30, were developed and enable transformation of ATCC 23726 at 6.2 x 10(4) and 1.5 x 10(6) transformants/mug plasmid DNA, respectively. The transformation efficiency of pHS30, which harbors a catP gene conferring resistance to chloramphenicol, was more than 1000-fold greater than that of pHS17. The improved transformation efficiency facilitated disruption of the chromosomal rnr gene using a suicide plasmid pHS19, the first demonstration of targeted mutagenesis in F. nucleatum. These results provide significant advances in the development of systems for molecular analysis in F. nucleatum.

Effect of intrauterine administration of oestradiol on postpartum uterine bacterial infection in cattle

After parturition fewer first dominant follicles are selected in the ovary ipsilateral to the previously gravid uterine horn in cattle. However, the presence of a large oestradiol-secreting follicle in the ipsilateral ovary is a predictor of fertility, possibly due to a localised effect of oestradiol which increases the rate of elimination of the ubiquitous uterine bacterial contamination that occurs after calving. The present study tested the hypothesis that oestradiol reduces uterine bacterial contamination when administered into the uterine lumen around the expected time for selection of the first postpartum dominant follicle. Animals were infused with saline (n=15) or 10mg oestradiol benzoate (n=15) into the previously gravid uterine horn on Days 7 and 10 postpartum. Peripheral coccygeal blood samples were collected daily and oestradiol concentrations measured by radioimmunoassay (RIA). Uterine lumen swabs were collected 7, 14 and 21 days postpartum for aerobic and anaerobic culture, bacteria were identified and growth scored semi-quantitatively. Plasma oestradiol concentrations were higher for treated animals between Days 7 and 14 (1.4+/-0.1 versus 2.0+/-0.2 pg/ml, P<0.05). Control animals had a similar bacterial growth score on Days 7 and 14, with a lower value on Day 21 (5.7+/-1.0 and 6.1+/-0.7 versus 0.3+/-0.1, P<0.05). However, treated animals had a surprising higher bacterial load on Day 14, than on Days 7 or 21 (7.1+/-0.9 versus 4.0+/-0.6 or 3.6+/-0.6, P<0.05). The increased score was attributable to more pathogens associated with endometritis on Day 14 than Day 7 (5.1+/-1.0 versus 2.5+/-0.5, P<0.05), in particular Prevotella melaninogenicus (1.5+/-0.5 versus 0.7+/-0.2, P<0.05) and Fusobacterium necrophorum (1.5+/-0.4 versus 0.3+/-0.2, P<0.05). In conclusion, administration of oestradiol into the uterine lumen surprisingly increased uterine pathogenic anaerobic bacterial contamination. Thus, it is unlikely that increased fertility associated with a first dominant follicle in the ipsilateral ovary is a consequence of the elimination of bacterial contamination by ovarian oestradiol.

[A case of Lemierre syndrome]

We present a case of Lemierre syndrome characterized by thrombophlebitis of the internal jugular vein with multiple metastatic foci after acute otopharyngeal infection in a 30-year-old woman. Despite treatment with tonsillectomy leading to a diagnosis of peritonsillar abscess, her condition worsened and she was admitted with high fever. Chest radiograph and CT scan of the thorax revealed multiple pulmonary cavities and pleural effusion on the right side. On neck CT, a thrombus was detected in the left internal jugular vein. She received with intravenous clindamycin (CLDM) and cefepime (CFPM) and progressively improved. Although Lemierre syndrome is a relatively uncommon disease with the potentially life-threatening complication of acute pharyngotonsillitis, this syndrome should be considered in cases of severe tonsillitis or pharyngitis.

Concurrent assessment of calpain and caspase-3 activation after oxygen-glucose deprivation in primary septo-hippocampal cultures

The contributions of calpain and caspase-3 to apoptosis and necrosis after central nervous system (CNS) trauma are relatively unexplored. No study has examined concurrent activation of calpain and caspase-3 in necrotic or apoptotic cell death after any CNS insult. Experiments used a model of oxygen-glucose deprivation (OGD) in primary septo-hippocampal cultures and assessed cell viability, occurrence of apoptotic and necrotic cell death phenotypes, and protease activation. Immunoblots using an antibody detecting calpain and caspase-3 proteolysis of alpha-spectrin showed greater accumulation of calpain-mediated breakdown products (BDPs) compared with caspase-3-mediated BDPs. Administration of calpain and caspase-3 inhibitors confirmed that activation of these proteases contributed to cell death, as inferred by lactate dehydrogenase release. Oxygen-glucose deprivation resulted in expression of apoptotic and necrotic cell death phenotypes, especially in neurons. Immunocytochemical studies of calpain and caspase-3 activation in apoptotic cells indicated that these proteases are almost always concurrently activated during apoptosis. These data demonstrate that calpain and caspase-3 activation is associated with expression of apoptotic cell death phenotypes after OGD, and that calpain activation, in combination with caspase-3 activation, could contribute to the expression of apoptotic cell death by assisting in the degradation of important cellular proteins.

Macrophage colony-stimulating factor is expressed in neuron and microglia after focal brain injury

In a previous study, we have demonstrated that damaged neurons within a boundary area around necrosis fall into delayed neuronal death owing to the cytotoxic effect of microglial nitric oxide (NO), and these neurons are finally eliminated by activated microglia. In this process, microglia are activated to release NO, increase in number, and accumulate toward the damaged area. In this study, we investigated the expression of macrophage colony-stimulating factor (M-CSF, also called colony stimulating factor-1; CSF-1) and other cytokines, which are reported to relate to activation, proliferation, or migration of microglia. The mRNA of M-CSF arose biphasically from 30 min to 1 hr and from 6 to 72 hr after the injury, as demonstrated by semiquantitative RT-PCR. However, another cytokine of granulocyte-macrophage CSF (GM-CSF) or interleukin-3 (IL-3), which causes proliferation of microglia in vitro, was not detected. From immunohistochemical studies, positive staining of M-CSF was observed mainly in neuron-specific enolase (NSE)-positive cells from 1 to 12 hr after the injury, and after that M-CSF became positive in Griffonia simplicifolia isolectin-B4 (GSA-I-B4)-positive cells from 24 to 72 hr in the boundary area around necrosis. These results suggest that neurons around the damaged area express M-CSF in the early phase after injury, which may initially activate microglia, and these activated microglia also express M-CSF later, causing further proliferation or migration of microglia themselves to eliminate damaged neurons or necrotic brain tissue.

The dangerous needles in the haystack of sore throats

The two reports of patients with sore throat published this month (p. 435, 436) highlight life-threatening aspects of that condition. Such rare but clinically highly significant entities remain buried among the far more common sore throats usually associated with the cold and wet British winter; but just because they are rare manifestations of a common disease leaves no room for complacency when assessing the patient with pharyngitis.

Isolation of fusobacteria from the oral cavities of malnourished Nigerian children living in agricultural and herding villages

A previous study demonstrated the presence and possible involvement of Fusobacterium necrophorum in the pathogenesis of noma lesions of children living in agricultural and herding villages in northwestern Nigeria. In order to determine if F. necrophorum was part of the oral flora of malnourished children with no noma lesions, a study of the fusobacteria present in the oral cavities of 30 children, 2-6 years of age in Sokoto State, was undertaken. Swabs taken of the oral cavity were cultured on selective fusobacteria medium using conventional anaerobic microbiological techniques. F. nucleatum was recovered from each child and F. necrophorum was isolated from the oral cavity of only one child. The presence of F. nucleatum and the lack of F. necrophorum, except in one case, suggests that the latter is not normal flora in the children at risk for noma. F. necrophorum, a putative trigger organism for noma may gain a foothold only when certain staging conditions (i.e., lowered host resistance and/or oral lesion) are present.

Fusobacterium pneumonia and death following uvulo-palato-pharyngoplasty

A case with a fatal outcome caused by infection with Fuso-bacterium species was seen in a patient recently operated on for heavy snoring with uvulo-palato-pharyngoplasty (UPPP). The mechanism of infection is discussed. It is concluded that a febrile episode seen in patients less than 2 weeks postoperatively should be considered a serious symptom and be treated intensively after thorough examination.

Mastoiditis, meningitis and venous sinus thrombosis caused by Fusobacterium necrophorum

The authors report a case of septic venous sinus thrombosis (VST) and meningitis occurring as an early complication of mastoiditis caused by Fusobacterium necrophorum. CT scan was normal, and cerebral angiography was required to diagnose the VST. The evolution was favourable with appropriate antimicrobial therapy and steroids.

Osteomyelitis of the pelvis due to Fusobacterium nucleatum

Anaerobic pelvic osteomyelitis occurs rarely in children. A case of Fusobacterium nucleatum osteomyelitis of the right ilium [correction of ileum] in a child without apparent risk factors is described. This case emphasizes the value of diagnostic aspirates. Therapy with a combination of intravenous and oral clindamycin led to successful resolution of the infection.

[Isolation and identification of oral spirochaetes and Fusobacterium in juvenile periodontitis]

Periodontal pocket specimens of 40 juveniles periodontitis (JP) and specimens from gingival sulcus in 40 normal juveniles (NP) were examined. 25 strains of anaerobic oral spirochaete (62.5%) (17 strains were Treponema microdentium, 3 strains macrodentium, 2 strains T orale, 3 strains Borrelia) and 21 strains of fusobacterium were isolated in 40 JP. In 40 NP, 2 strains of spirochaetes (5%) and 3 strains fusobacterium (7.5%) were found. This study shows that there is a relationship between the infection of spirochaeta, fusobacterium and JP.

Parietal lobe abscess after routine periodontal recall therapy. Report of a case

This paper reports on a case of a 70-year-old physician diagnosed with a parietal lobe abscess following such treatment. After stereotactic biopsy and drainage and a 6-week course of intravenous antibiotic treatment, the patient recovered with minimal neurologic deficits. Although brain abscesses are not commonly encountered in practice, clinicians must be aware of the potential virulence of the anaerobic components of the periodontal pocket and the possibility of resulting systemic infection, which can produce a life-threatening situation.

Lemierre's postanginal septicemia: internal jugular vein thrombosis related to pharyngeal infection

We have described a case of septic thrombophlebitis of the internal jugular vein after an anaerobic pharyngeal infection. This and other septic thrombophlebitides are a part of Lemierre's postanginal septicemia. Early diagnosis and appropriate antimicrobial therapy are important to avoid sequelae.

Tropical ulcer--a reappraisal based on recent work

Tropical ulcer is a disease which predominantly affects young children in the tropics. The course of the disease can be interrupted in the early stages by the administration of antibiotics so it seems likely that infection may play a role. The disease extends rapidly from the initial lesion, a tiny papule, to a large area of necrosis. This makes a toxic factor likely in the pathogenesis. The epidemiology and some of the causative factors of this disease are currently being investigated. Patients with tropical ulcers were assessed, in areas where the disease is still endemic (Gambia, Papua New Guinea, southern India and Fiji), by a paediatrician or a dermatologist. All patients had swabs taken from the ulcers for bacteriological examination. Skin biopsies were taken from the edge of the ulcers as often as possible. The bacteriological samples were transported anaerobically to London where the laboratory work was performed. The results are discussed in relation to previously reported work.

Anaerobic septicemia secondary to Fusobacterium mortiferum

A case of anaerobic sepsis associated with Fusobacterium mortiferum is reported. Blood cultures from a 60-year-old man with type II diabetes mellitus, hypertension, severe atherosclerotic cardiovascular disease, and renal insufficiency revealed on a gramstained smear highly pleomorphic gram-negative bacilli with bizarre forms and round bodies. Growth of the organism on nonselective anaerobic media and analysis of its pattern produced results characteristic of Fusobacterium mortiferum.

Anaerobic bacterial endophthalmitis in the rabbit

Anaerobic bacterial endophthalmitis was studied in rabbits following intravitreal injection of live Fusobacterium necrophorum. Clinical response, bacterial recovery, and histopathology were studied. An inoculum of approximately 50 organisms produced endophthalmitis in 59% of injected eyes, while 1000 or more organisms produced endophthalmitis in 100% of injected eyes. The course and severity of disease seemed to be independent of the concentration of bacteria above a minimal inoculum size. Affected eyes showed progressive endophthalmitis. Histopathologic changes corresponded to the clinical gradation of endophthalmitis, including progressive retinal necrosis.

Dissecting retropharyngeal abscess due to Fusobacterium necrophorum in an adult

I have described an adult patient who had dissecting retropharyngeal abscess complicated by pneumonia, mediastinitis, pericarditis, sepsis, and status epilepticus.

Anaerobic orbital cellulitis

A 10-year-old boy with orbital cellulitis died seven weeks after admission to the hospital despite intensive surgical intervention and medical therapy. We isolated many anaerobic bacteria from the orbit, frontal sinus, and epidural space. Orbital cellulitis, which often occurs by direct extension from infected paranasal sinuses, commonly affects children and young adults, and is a potentially lethal disease, if left untreated. Heightened awareness of the role of anaerobes in chronic sinusitis and of the possibility of an anaerobic orbital cellulitis may lead to the identification of more cases. Penicillin G appears to be the first drug of choice in cases with suspected anaerobic orbital cellulitis. Chloramphenicol and clindamycin should be considered, if treatment with penicillin fails. Antibiotics alone should not be considered as a panacea, and surgical drainage is often the most compelling consideration.

Fusobacterium nucleatum pericarditis

A pericardial effusion was diagnosed by echocardiography in a 49 year old man who suffered acute cough, orthopnea, and chest pain. Because of a positive tuberculin skin test, mycobacteria were initially suspected as the cause of the pericarditis. The patient was therefore treated with antituberculosis drugs. The pericardial effusion failed to resolve, however, and pericardiectomy was performed. Culture of the pericardial fluid yielded pure Fusobacterium nucleatum growth. The patient responded to antibiotic therapy and was in good health 3 weeks after being discharged from the hospital. This represents the first report of F. nucleatum pericarditis.

Fusobacterium necrophorum septicemia following oropharyngeal infection

Fusobacterium necrophorum septicemia developed in five patients after an oropharyngeal infection. Four patients had sore throat or neck pain, and two had findings of jugular vein septic thrombophlebitis. Metastatic abscesses, including embolic pneumonia, empyema, septic arthritis, and osteomyelitis, also occurred. Four patients recovered and one died. Proper treatment requires recognition of the oropharyngeal source of the septicemia and its differentiation from endocarditis. Antibiotic therapy should be prolonged, and metastatic abscesses drained.

Fatal peritonitis following IUD-associated salpingitis

Previous reports have implicated the Dalkon shield intrauterine device (IUD) in septic second trimester abortion and maternal death from sepsis. In the case reported here, Fusobacterium necrophorum, a rarely pathogenic vaginal anaerobe, gained access to the uterus in a woman wearing a Dalkon shield and caused acute parametritis, overwhelming peritonitis, systemic sepsis, and death. It is well known that IUDs can contribute to the development of serious pelvic infections, and in this case it is possible that the Dalkon shield was the cause of the ascending infection into the uterus.

Anaerobic bacteria in pediatric infections

Anaerobic bacteria normally outnumber aerobic bacteria in the oral cavity and the gastrointestinal tract. They have been isolated from pediatric patients with various diseases. Anaerobic bacteria have been shown to colonize newborns immediately after delivery. These organisms are associated with cellulitis at the site of fetal monitoring, neonatal aspiration pneumonia bacteremia, conjunctivitis and omphalitis. Clostridial spores have been found in cases of necrotizing enterocolitis. Botulism of the newborn has been reported.

The gram-negative bacillary pneumonias

With increasing age, chronic underlying disease, and debility, the oropharyngeal flora are colonized with aerobic gram-negative bacilli. In this debilitated population, gram-negative bacillary pneumonias (GNBP) are increasingly common. GNBP account for two of every three pneumonia deaths today. As a group, the mortality of GNBP is about 50%. Although the original epidemiologic surveys were done 15 years ago, there is little evidence for an improving case fatality rate despite the appearance of aminoglycoside antibiotics, carbenicillin, and cephalosporins. In susceptible patients, GNBP pneumonias occur both in the community and as nosocomial infections. Recognition of the dangers of contaminated reservoir nebulizers or other similar devices used in inhalation therapy has led to epidemiologic measures within hospitals that have markedly decreased the incidence of this nosocomial GNBP. The role of Gram stain and culture of expectorated sputum and similar examinations of specimens obtained by transtracheal aspiration, fiberoptic bronchoscopy, and lung biopsy in the diagnosis of GNBP are discussed in this review (see Criteria for Diagnosis). In the presence of pulmonary emphysema, congestive heart failure, mixed gram-negative bacillary infections, or the use of immunosuppressive drugs, typical characteristics of individual GNBP may not be apparent. Typical features of Pseudomonas aeruginosa, Escherichia coli, Enterobacter, Proteus, Hemophilus, and anaerobic pulmonary infections are described. Early recognition and institution of appropriate antibacterial agents are emphasized, particularly in GNBP caused by Pseudomonas aeruginosa, Escherichia coli, or Friedländer's bacillus, where the mortality approaches 70%. The mortality of GNBP, including Enterobacter, Proteus, Hemophilus, and anaerobic GNBP, is about 20%. The latter figure is the same as the mortality of pneumococcal pneumonia in similar patients.

Primary meningitis caused by Bacteroides fragilis and Fusobacterium necrophorum

A fatal case of meningitis due to Bacteroides fragilis and Fusobacterium necrophorum is reported. This appears to be the first case in which meningitis due to these organisms was not secondary to a disease elsewhere in the body. The organisms are difficult to culture and strict anaerobic methods should be used whenever they are suspected. Intravenous metronidazole is probably the antibiotic of choice.

Acute suppurative parotitis caused by anaerobic bacteria: report of two cases

Staphylococcus aureus is the predominant pathogen in acute suppurative parotitis. Although anaerobic bacteria are prevalent in the normal oral and upper respiratory tract flora and frequently are involved in oral and facial infections, they have seldom been isolated from patients with suppurative parotitis. It may be that a role for anaerobes in parotitis has not been documented because of inadequate specimen transport or anaerobic culture techniques. We describe two cases of acute suppurative parotitis in which cultures yielded anaerobic bacteria. In one case, no aerobes were isolated; in the other, the anaerobe was the predominant organism numerically.

Anaerobic spinal epidural abscess. Case report

An acute spinal epidural abscess is reported from which a pure growth of the anaerobe Fusobacterium necrophorum was isolated. The mode of infection and pathogen makes it unique. The literature concerning the bacteriology of epidural abscess and the implications of anaerobic epidural infection are discussed.