Uncommon Organisms Research Articles

Acute vascular access catheters for haemodialysis: complications limiting technique survival.

The use of acute vascular access catheters (AVACs) has facilitated the delivery of haemodialysis to patients lacking functioning access. A review of the experience of a tertiary Australian renal treatment centre, consisting of 205 sequential AVACs in 93 patients, was undertaken over 1 year, to identify issues limiting technique survival. Acute vascular access catheters were inserted as acute dialysis access for patients with chronic renal failure (CRF; 21%), failed grafts or fistulae (18%), acute renal failure (12%), failed chronic ambulatory peritoneal dialysis (CAPD; 8%) or failed prior AVACs (37%). The majority of AVACs were on the right (74%), and the placement site was simple jugular (69%), tunnelled jugular (15%), femoral (12%), or subclavian (4%). During follow up, 198 of 205 AVACs were removed. The mean AVAC survival was superior (P < 0.0001, Fisher's protected least significant difference (PLSD) for tunnelled jugular AVACS (62 +/- 46 (SD) days) compared with simple jugular (20 +/- 19), subclavian (18 +/- 13) and femoral (7 +/- 6). Causes for AVAC removal were: elective (47%), blockage (31%), infection (20%) or cracked catheter (1%). Routine postremoval tip cultures grew coagulase negative Staphylococcus (CNS, 46%), negative culture (33%), methicillin-resistant Staphylococcus aureus (MRSA; 9%), Staphylococcus aureus (9%), Gram-negative rods (1%), Pseudomonas (0.5%) or other uncommon organisms (2%). Blood cultures were drawn through the AVAC in the setting of suspected bacteraemia in 42 of 198 AVACs. Blood cultures were negative in 40%. Positive cultures included Staphylococcus species in 55%: including MRSA (19%), Staphylococcus aureus (29%) and CNS (34%). Rare cultures identified Escherichia coli (2%) or Serratia (2%). Infection and blockage significantly reduced AVAC survival, affecting more than 50% of cases. Approaches to minimize these complications are likely to lead to improved clinical outcomes with AVAC use.

Pyogenic Spinal Epidural Abscess

Pyogenic Spinal Epidural Abscess

ATYPICAL HAND INFECTIONS

The diagnosis and treatment of an atypical hand infection present a distinctive challenge for the hand surgeon. Infections caused by these uncommon organisms occur more often in immunocompromised patients. This article emphasizes the salient features of mycobacterial, nocardial, and fungal infections of the hand. With an accurate and timely diagnosis, appropriate surgical and pharmacologic treatment may eradicate these unusual infections.

Fulminant infection by uncommon organisms in animal bite wounds.

In 1995 and 1996, 215 patients exposed to different species of animals were treated at the Amarnath Polyclinic, Balasore, in India. Among them were two children infected by uncommon organisms,...

Trends of childhood infective endocarditis in Israel with emphasis on children under 2 years of Age.

This study retrospectively analyzed the characteristics of infective endocarditis (IE) in children in light of recent advances in pediatric cardiology. We evaluated 25 consecutive patients with IE from 1980 to 1991 at a tertiary Children's Medical Center in Israel. The incidence of IE increased significantly over the second half of the study period, owing mainly to an increase in the number of patients less than 2 years old. Concomitantly, the causative microorganisms changed considerably, with a decrease in viridans streptococci, an increase in staphylococci and other uncommon causes of IE, and increased antibiotic resistance. Children under the age of 2 years, previously considered uncommon IE patients, accounted for 47% of the IE cases during the second half of the study period. The infection often (78%) appeared in children with complex congenital heart diseases, commonly after early palliative or definitive cardiac surgery. Infants who underwent systemic-to-pulmonary shunting, especially with implantation of foreign materials, were at highest risks. IE was more often hospital-acquired (56% versus 6%) and acute (56% versus 44%) in the younger children than in the older ones and often lacked the typical clinical presentation of the disease. In addition, uncommon causative organisms were noted more frequently (67% versus 13%; p = 0.009) in the younger group. The study shows a significant increase in IE in infants and young children with distinctive underlying conditions, clinical presentation, and microbiologic findings, all of which should be considered currently for the diagnosis and treatment of pediatric IE.

Escherichia coli infection of an abdominal aortic aneurysm

With the introduction of antibiotics and decrease in bacterial endocarditis mycotic aneurysms have become rare. Infection of a pre-existing aortic aneurysm is uncommon and Gram-negative organisms, especially Salmonellae, have been implicated in most of the cases reported. Infection usually follows episodes of bacteraemia. Escherichia coli infection has been reported as a rare causative agent. We describe a case of E. coli aortic aneurysm infection and discuss the problems associated with diagnosis and management .

Bacterial complications of transplantation: diagnosis and treatment

Bacterial complications develop mainly after transplantation during the period before engraftment takes place. Wound infections, urinary tract infection and pneumonia are the commonest complications of solid organ transplantation and generally involve Gram-negative bacilli and Staphylococcus aureus. However, Gram-positive cocci will predominate when selective oral antimicrobial prophylaxis is given as is frequently the case in bone marrow transplant recipients. Oromucositis, induced by total body irradiation or anthracyclines, result in more bacteraemia due to oral viridans streptococci. The use of central intravenous catheters leads to an increase in bacteraemia and infection due to coagulase-negative staphylococci. Patients requiring intensive care are also at risk of nosocomial infections including legionellosis. Once engraftment has occurred, there is much less risk of bacterial infection but patients remain vulnerable to the intracellular pathogens Listeria monocytogenes, non-typhoid salmonellae, Norcardia spp. and mycobacteria for as long as they require immunosuppression. Any rejection crisis must be treated aggressively with high-dose steroids or other agents which further undermine an already fragile immunity. In bone marrow transplant recipients, graft versus host disease and its treatment exerts a more profound effect on immunity and often coincides with cytomegalovirus infection which compromises the patient even further. Such patients are again at risk of infection with the same range of pathogens encountered during neutropenia since the oral mucosa, gut and catheter, if one is present, provide the same portals of entry. Immunosuppressive therapy, in some centres, is discontinued once the risk of graft versus host disease is reduced, although the reconstitution of the immune system is a lengthy process and there is a continued deficiency of IgG which renders patients unable to opsonise the encapsulated bacteria Streptococcus pneumonia and Haemophilus influenzae. In contrast to bone marrow transplant recipients, those with a solid organ transplant require life-long immunosuppression and so remain susceptible to infections with intracellular pathogens and, even with minimal immunosuppression, there will always be the risk that common bacteria will cause infection in unusual places and that uncommon organisms will be involved in apparently straightforward infections.

Salmonella paratyphi — an Unusual Cause of Primary Septic Arthritis of the Hip

Salmonella paratyphi is an extremely rare cause of primary septic arthritis of the hip, especially in the U.K. The presentation is no different from other causative organisms. A case is described illustrating that uncommon organisms can cause septic arthritis and that for successful treatment correct organism identification is paramount.

Infective endocarditis

The subject of infective endocarditis continues to attract the attention of many physicians. Optimal management of endocarditis requires integrated input from experts in diverse specialties: infectious diseases, cardiology and echocardiography, surgery, neurology, microbiology, and pathology. Areas of active investigation include defining the various uses of echocardiography; elucidating natural history of endocarditis in patients at increased risk, especially drug abusers; conducting follow-up studies on patient survival; evaluating new treatment options and prophylaxis; and defining the shifting spectrum of uncommon organisms that cause endocarditis. Decisions about the optimal timing of surgery remain challenging. New therapeutic options, including home therapy, are emerging. Although microbiologic cure can be achieved in most patients with endocarditis, the long-term prognosis remains surprisingly poor, and many patients require valve surgery.

Activity of meropenem and other antimicrobial agents against uncommon gram-negative organisms.

The in-vitro activity of meropenem and other antimicrobial agents was tested by agar dilution against 113 uncommon Gram-negative pathogens. Both meropenem and ceftriaxone showed the most activity against the test isolates. The potency of meropenem was greater than imipenem against Pasteurella multocida, Eikenella corrodens, Haemophilus parainfluenzae, Moraxella spp., Kingella spp., and Actinobacillus actinomycetemcomitans. Further work is necessary to assess the in-vivo activity of meropenem against these Gram-negative isolates.

The changing pattern of infective endocarditis in childhood

Forty-eight cases of infective endocarditis (IE) that occurred in 42 patients with congenital heart disease were reviewed from 1970 through 1990 and were compared with a 20-year review of 108 cases diagnosed between 1953 and 1972. The review demonstrates that the natural history of IE in children has changed over the last 2 decades, with half of the cases occurring after surgery for congenital heart disease. In the postoperative group, 46% of patients had undergone. valve replacement and 7 of these (29%) had a right ventricular to pulmonary artery valved conduit as the site for IE, suggesting significant additional risk in this setting. Among patients with nonsurgically treated congenital heart disease and IE, mitral valve prolapse has emerged as an important underlying heart lesion occurring in 29% of patients. The bacterial spectrum has shifted, with a significant increase in the incidence of uncommon causative organisms. Mortality has continued to decline with survivorship. of 90% in this series.

Rational Approaches to the Treatment of Culture-Negative Infective Endocarditis

The microorganism responsible for infective endocarditis may not be grown on blood culture in as many as 25% of cases. While this is to be expected with such relatively uncommon organisms as Coxiella burnetti, in most cases failure to grow the organism is likely to be due to either a low concentration of bacteria in the blood or because antibiotics were given before blood was taken for culture. The antibiotic treatment of culture-negative cases should be based on the assumption that the organisms responsible are the same as those found in cases with positive cultures, covering the most likely possibilities in such different circumstances as spontaneous infections of natural valves, endocarditis following cardiac surgery, early and late prosthetic valve endocarditis and infections associated with intravenous drug abuse.

Animal models for dermatomycotic infections.

Under natural conditions the skin of man and animals is exposed to numerous agents and may be subject to infections by various pathogenic organisms, including viruses, bacteria, and fungi. In predisposed individuals or those exposed to large concentrations of pathogens, the infection is more pronounced, more invasive, more extended, and less susceptible to therapeutic agents. There are a number of uncommon organisms that are often considered to be saprophytic yet turn to be infectious agents. In this chapter the most common fungal pathogens used as test species in animal models for dermatomycoses are discussed, and the usefulness of the animal models for studying infection and screening antifungal compounds is evaluated.

The Sore Throat: Pharyngitis and Epiglottitis

Sore throat can be caused by different microorganisms and dis- eases. Most cases of acute pharyngitis are caused by group A strepto- coccus or viruses; however, uncommon organisms may be suggested by other clinical information or the persistence of symptoms. A thor- ough history and physical examination are essential for the appro- priate selection of diagnostic tests for sore throat. Routine testing for the uncomplicated case should consist of a pharyngeal culture in most patients, with rapid streptococcal antigen testing only for the more severe cases. Those with positive streptococcal tests should be treated to prevent rheumatic fever and mitigate symptoms in severe cases. Sore throat caused by viruses usually resolves spontaneously. Cases that persist should be thoroughly re-evaluated, with alterna- tive causes being considered. Acute epiglottitis is a medical emer- gency and requires treatment with appropriate antibiotics for He- mophilus influenzae type b and intubation.

Utility of urine cultures in the emergency department

Urinary tract infection (UTI) is a common problem treated by emergency physicians. A midstream urine sample remains the most frequent method of culture collection. Although midstream urine culture growing more than 10(5) colony-forming units per milliliter (cfu/mL) has been considered diagnostic of UTI, high false-positive and false-negative rates as well as a lack of precision have been associated with this method of collection. Alternative methods of establishing the diagnosis of UTI have excellent sensitivity and may be utilized at the time of patient presentation. These include the detection of leukocyte esterase activity in urine and the presence of one or more bacteria on microscopic examination of an unspun urine sample. Women of child-bearing age represent the vast majority of patients seen with UTI. Uncomplicated infection of the urinary tract has a generally benign course in these patients, and is rarely associated with long-term complications. In addition, these patients are infected with a predictable spectrum of uropathogens that respond to the commonly used antibiotics. It appears that urine cultures provide little additional information in this patient population. Urine cultures should be obtained in patients at high risk for pyelonephritis or bacteremia/urosepsis, as well as in those expected to have uncommon or resistant organisms.

Puerperal mastitis: Causes, prevention, and management

Breast infection can be a pathologically based negative influence on breast feeding. There are basically five types of lactational mastitis: subclinical mastitis, acute puerperal mastitis (cellulitis and adenitis), supperative mastitis, mammary infection with uncommon organisms, and virus infection in mammary neoplasms. The first three types are seen most often. Mastitis patients present, along with fever, a rapid pulse, and hot, reddened, tender areas on one or both breasts. Symptoms are most severe in supperative mastitis. In these cases, the developing breast abscess may be clearly identifiable. Nipple trauma and engorgement are thought to be predisposing factors to mastitis. Nipple trauma may lead to fissured nipples, thereby facilitating entry of bacteria into the connective tissue of the breast and development of acute cellulitic mastitis. Engorgement leads to stasis of milk and plugged milk ducts, which may create a setting conclusive to development of acute adenitis. Nurse-midwives should be actively involved in prevention and early detection of mastitis. Prevention may include instruction in hand expression and breast massage; encouragement of early, unrestricted nursing; identification of mothers with increased risk of nipple trauma and engorgement; instruction in signs and symptoms of infection; identification of support and information sources; and scheduling of early postpartum clinic visits. Treatment of mastitis includes rest in bed, increased oral fluids, temperature monitoring, and either continuation of breast feeding or discontinuation with binding of breasts and application of ice packs. Research seems to indicate that continuation is preferable. Treatment with antibiotics, usually antistaphylococcal drugs, is also necessary.

Isolation ofKlebsiella ozaenaeandKlebsiella rhinoscleromatisin a General Hospital

Klebsiella ozaenae and Klebsiella rhinoscleromatis are uncommon organisms usually associated with granulomatous or necrotizing disease of the upper airways. Seven patients are described, non of whom had characteristic clinical manifestations of infection with these species. The organisms were recovered from mixed wound infections or sputum of five patients, and from the blood of three patients. Antibiotic sensitivity patterns were unusual and included susceptibility to both ampicillin and carbenicillin.

IMMUNOFLUORESCENCE TECHNIQUES FOR DEMONSTRATING BACTERIAL PATHOGENS ASSOCIATED WITH CEREBROSPINAL MENINGITIS. I. CLINICAL EVALUATION OF CONJUGATES ON SMEARS PREPARED DIRECTLY FROM CEREBROSPINAL FLUID SEDIMENTS.

Abstract Techniques were described for the cultivation and immunofluorescent identification of Hemophilus influenzae, Diplococcus pneumoniae, Neisseria meningitis, and eight less common pathogens in specimens of cerebrospinal fluid from 100 patients with bacterial meningitis. A comparison of the results obtained by conventional methods and by immunofluorescent staining indicated that the latter method was fully an sensitive as the former and was more accurate in treated cases. Some of the dangers involved in the use of the Gram stain of the sediment as a tool for presumptive diagnosis were discussed, as were shortcomings of fluorescent antibody staining, particularly in infections caused by uncommon gram-negative organisms. The immunofluorescent staining technique was recommended for the rapid screening of spinal fluid specimens, as well as of cultural isolates.