Histologic reactions to cutaneous infections by Mycobacterium haemophilum.

Mycobacterium haemophilum is an emerging pathogen in immunocompromised patients. We report the clinical and histologic findings of 16 skin biopsies from 11 patients with culture-proven infections by M. haemophilum. The patients had leukemia or non-Hodgkin's lymphoma. Ten of them had undergone bone marrow transplantation. When the skin biopsy specimens were taken, a portion of the skin was simultaneously submitted to a microbiology laboratory for cultures. The remaining skin was processed routinely. Acid-fast bacilli were found in 11 of 16 lesions. The number of histologically detectable organisms was typically low: nine biopsies had fewer than three bacilli per 50 oil immersion fields. The most common histologic pattern was a mixed suppurative and granulomatous reaction (7 of 16 biopsies). Four biopsies showed well-formed epithelioid granulomas. Two showed necrosis, one of which was ulcerated. One lesion was a subcutaneous abscess. Two biopsies showed a mixed lichenoid and granulomatous dermatitis. In one of them, the granulomatous reaction was focal and small. One biopsy lacked a granulomatous tissue reaction altogether; it showed an interface dermatitis, a perivascular and periadnexal lymphocytic infiltrate, and necrotizing lymphocytic small vessel vasculitis. A subsequent biopsy from the same patient additionally showed a focal granulomatous reaction. Our observation that infections by M. haemophilum can present with nongranulomatous or pauci-granulomatous reactions without necrosis is of note. Failure to suspect mycobacterial infection in such reactions contributes to probable underreporting of M. haemophilum and to misdiagnoses. Furthermore, our findings emphasize the importance of simultaneous biopsies for culture and histology in immunocompromised patients.     

Identification of HIV patients with active pulmonary tuberculosis using urine based polymerase chain reaction assay

BACKGROUND: Despite the increased dissemination of tuberculosis among HIV infected patients, the diagnosis is difficult to establish. Traditional microbiological methods lack satisfactory sensitivity. We have developed a highly sensitive and specific nested polymerase chain reaction (PCR) capable of detecting Mycobacterium tuberculosis DNA in urine specimens and have used this test to examine urine specimens from HIV patients with active pulmonary tuberculosis. METHODS: Urine specimens from 13 HIV infected patients with microbiologically proven active pulmonary tuberculosis, 10 AIDS patients with non-tuberculous mycobacterial infection (documented by blood culture), 53 AIDS patients with no evidence of mycobacterial disease, and 80 healthy subjects (25 with positive skin test to purified protein derivative) were tested for M tuberculosis using PCR, acid fast staining (AFS), and culture. RESULTS: Of the urine specimens from patients with active tuberculosis, all tested positive by PCR, two by culture, and none by AFS. No reactivity was observed in urine specimens from patients with non-tuberculous mycobacterial infection. Of the 53 AIDS patients without mycobacterial infection, one had a positive urine PCR. Normal subjects were all negative. CONCLUSIONS: Urine based nested PCR for M tuberculosis may be a useful test for identifying HIV patients with pulmonary tuberculosis.     

Lack of skin test reactivity to common mycobacterial antigens in human immunodeficiency virus infected individuals with high CD4 counts.

BACKGROUND: T cell response to mycobacterial antigens may be directed against those antigens common to all mycobacteria (group i), those restricted to slow (group ii) or fast growers (group iii), or those which are species- or subspecies-specific (group iv). These responses were assessed by skin testing patients infected with the human immunodeficiency virus (HIV) and healthy controls with reagents derived from different strains of mycobacteria. METHODS: Skin test responses to new tuberculins prepared from Mycobacterium tuberculosis, M avium serotypes 4 and 8, and either M intracellulare or M flavescens antigens were evaluated prospectively in 51 HIV infected patients and 67 healthy controls. RESULTS: Assessment of induration at 72 hours showed absence of skin test response to common mycobacterial antigens in all 27 HIV positive patients with CD4 counts of > or = 400/mm3 (range 400-1594, median 540) compared with 27% reactivity in controls; complete anergy was demonstrated in 24 patients with CD4 counts of < 400/mm3. By contrast, no difference in species or subspecies-specific responses was found between healthy controls and HIV positive patients with CD4 counts of > or = 400/mm3. CONCLUSIONS: Subsets of CD4+ T helper cells are instrumental in determining the balance between cell-mediated and humoral immunity. One T helper subset (TH1) produces cytokines that increase cellular immunity and is stimulated by group i common mycobacterial antigens. Lack of this response, but preservation of responses to species-specific antigens while CD4 counts are near normal, may indicate an early failing of TH1 immunity and explain the increased susceptibility of HIV positive patients to mycobacterial infection early on in the evolution of their HIV infection.     

Rapidly growing nontuberculous mycobacteria: a new enemy of the cardiac surgeon

A review of atypical mycobacterial infections complicating cardiac operations is presented. Proven sources of infections at different institutions include contaminated porcine valves and municipal water supply, but the mode of transmission in the great majority of patients remains unclear. There are two principal clinical forms of atypical mycobacterial infections after cardiac operations--endocarditis and sternal osteomyelitis. The latter has characteristics resembling tuberculotic "cold abscess." Specialized laboratory testing is necessary to confirm the diagnosis, and surgeons may have to take the initiative to request special microbiological investigation in cases where infection is clinically suspected but routine cultures are reported as "negative." The prognosis for patients who have any atypical mycobacterial infection after a heart operation is severe. Those infected with the strain chelonei and those whose cardiac chambers were entered during operation fare worse. This dim clinical prognosis may be improved by appropriate and aggressive antibiotic and surgical therapy. Awareness of the urgency of special bacteriological studies is the key to successful management.     

Atypical mycobacterial infection of the parotid gland

A localized atypical mycobacterial infection of the major salivary gland is a rare disease. In this report the cases of three patients with this lesion are presented. The diagnosis was based on the clinical picture, skin testing with specific antigens, bacteriologic culture, and histopathologic findings. The patients were successfully treated by total parotidectomy with facial nerve preservation, which in our opinion is the therapy of choice in localized atypical mycobacterial infections.     

A prospective, randomized trial of abdominal wound drainage in gastric bypass surgery.

A prospective, randomized trial was conducted in 194 morbidly obese patients who had gastric bypass to determine the effect of subcutaneous closed suction drainage on wound infection rates. There was no difference in the incidence of postoperative wound infection with the use of drains compared with simple abdominal closure. Organisms isolated from infected wounds were predominantly skin flora and did not differ between the two groups. Patients with wound infections had significantly prolonged hospitalizations compared with those without infections, but in the subgroup with wound infections there was no difference in hospitalization time between the drainage or control groups.     

Histoplasmosis infection presenting as an isolated subcutaneous periarticular upper limb swelling in the immunosuppressed patient

Atypical mycobacterial and fungal infections may occur in immunosuppressed patients. The impaired host response can make the clinical presentation atypical. Blood and tissue cultures may be negative in the acute phase of the illness, which can lead to a delay in diagnosis. In those patients with AIDS or other underlying immunosuppressive conditions, histoplasmosis cannot always be eradicated, but treatment that achieves chronic suppression may be adequate to maintain functional capacity. This report describes two immunosuppressed patients who presented with isolated subcutaneous histoplasmosis infection around the wrist.     

Reduction of infection rates in abdominal incisions by delayed wound closure techniques.

A low incidence of infection in abdominal wounds after contaminated, infected, and selected clean-contaminated operations was achieved after delayed wound closure of the skin and subcutaneous tissue. An effective method of delayed primary closure is described. Four days of open wound management with Xeroform gauze between the skin and subcutaneous tissue is followed on the 5th day be removal of the Xerform and skin approximation with Steri-Strips. Proper use of this technique is based upon appropriate assessment of wound contamination and infection risk factors. All contaminated and infected wounds are best managed with delayed primary closure and, when not possible, with healing by secondary intention. Delayed primary closure should be applied to clean-contaminated wounds if the patients are older than 60 years or have associated diabetes mellitus, malnutrition, or obesity.     

Mycobacterial soft tissue infections in North Queensland

BACKGROUND: Mycobacterial soft tissue infections are a heterogeneous group of infections that usually require a variety of therapeutic methods for cure. North Queensland has an environment, which predisposes to several such infections. The aim of this study was to assess the incidence and epidemiology of mycobacterial soft tissue infections in North Queensland and to review surgical and non-surgical interventions in these conditions. METHODS: This study was a retrospective review of all patients with a proven mycobacterial soft tissue infection, seen between 1997 and 2005 in a tertiary referral centre in North Queensland. RESULTS: In total, 34 patients were identified. The most common causative organisms were Mycobacterium fortuitum (44%), M. ulcerans (17.6%) and M. abscessus (11.8%). The risk factors identified were the male sex, lower-limb involvement and preceding trauma including surgery. Twenty-four (70.6%) patients had surgical excision or debridement with a variety of adjuvant antimicrobial therapies. There were eight (23.5%) local recurrences. CONCLUSION: The optimal management of soft tissue mycobacterial infections includes early microbiological identification based on tissue biopsy, appropriate combination antimicrobial therapy and early wide surgical excision where appropriate. North Queensland has a unique environment, which may predispose to these infections. An awareness of this is essential to surgical practice in the region.     

A radical approach to bacterial panniculitis of the abdominal wall in the morbidly obese

The morbidly obese patient, although at risk for many perioperative complications of radical surgery, paradoxically presents the opportunity for wide excision of abdominal soft-tissue infections. This report describes the successful radical surgical management of bacterial panniculitis of the abdominal wall occasioned by a variety of extrafascial and intraperitoneal sources in 13 patients. All patients were followed up for a minimum of 2 years, except for one patient who died 2 months after hospital discharge. The remainder are alive with intact fascial closure and no pannicular infection. A radical approach to the infected abdominal wall, incorporating wide en-bloc excision of skin, subcutaneous tissue, muscle, and strangulated intestine, facilitates successful fascial and skin closure in a noninfected field in the morbidly obese.     

Is umbilical flora responsible for wound infection after laparoscopic surgery?

To our knowledge, the association of umbilical flora and infections has not been studied yet. The aim of this study was to identify the causative agents for trocar site infections and to highlight whether there is association between umbilical flora and trocar site infections. One hundred consecutive patients who had undergone laparoscopic surgery were studied. Microbiological samples were taken from the umbilicus before (group 1) and after (group 2) antisepsis with povidone-iodine. Microbiological assessment was done for wounds suspected to be infected, and the wounds with positive cultures were classified as group 3. The incidence of wound infection was 8%. One hundred percent of the infections were associated with the extraction trocar. Eighty-nine percent of all of the infections occurred after laparoscopic cholecystectomy, whereas 11% occurred after laparoscopic appendectomy. The micro-organisms in group 3 did not belong to the skin flora, unlike the micro-organisms in groups 1 and 2, but hospital-acquired pathogens were responsible for the infections. The umbilical flora and the bile are not the source of the surgical site infections after laparoscopic surgery in our study despite the considerations in the literature.     

Surgical management of resistant mycobacterial tuberculosis and other mycobacterial pulmonary infections

Between August 1983 and October 1990, 42 patients with resistant Mycobacterium tuberculosis underwent 44 pulmonary resections. During the same time, 38 patients with mycobacterial infections other than tuberculosis had 41 pulmonary resections. All patients either were poor candidates for medical therapy alone or had existing complications requiring surgical intervention. There was one operative death in each group, both from adult respiratory distress syndrome (postpneumonectomy pulmonary edema). Complications were high, with bronchopleural fistula most commonly occurring after right pneumonectomy in patients infected with Mycobacterium avium with superimposed infection with nonmycobacterial pathogens. In patients undergoing pneumonectomy for resistant Mycobacterium tuberculosis, the left lung was most often resected. It is recommended that if localized disease is present and medical treatment is likely to fail, pulmonary resection should be performed for resistant Mycobacterium tuberculosis infection after 3 months of drug-specific therapy. Muscle flaps were used frequently to avoid residual space and bronchial stump problems. Earlier resection in patients with indolent nontuberculous mycobacterial pulmonary infections is advocated before extensive polymicrobial contamination and right lung destruction.     

Pulmonary infection in immunocompromised hosts

While typical pulmonary infections can be cured with antimicrobial agents, three types require surgical lung resection: those in immunocompromised patients; those with acquired resistance to medication; and those caused by microorganisms against which there are no effective drugs. We discuss these three types from the viewpoint of physicians. With the development of chemotherapy for malignant disease, patients with leukemia can be cured with bone marrow transplantation. During the leukopenia accompanying chemotherapy, Aspergillus sp. can infect the lungs. Aspergillus infections are resistant to antimicrobial agents, and thus surgical resection is necessary. Aspergillus infections may occur in previous sites of pulmonary tuberculosis lesions after the tuberculosis is cured producing massive hemoptysis. In this case, surgical resection is also needed. When patients who are immunocompromised due to various underlying diseases become infected with multidrug-resistant tuberculosis, they require surgical resection. Finally, when lesions of nontubercular mycobacterial infection are found, these patients also require surgical lung resection.     

Mycobacterial infections in marrow transplant patients

Bone marrow transplant recipients undergo ablation of host immune defenses with total-body irradiation or high dose chemotherapy, or both. Over a 5.6-year period, mycobacterial infections were observed in 7 of 682 patients with leukemia who received marrow grafts. Four patients had pulmonary and three extrapulmonary infection. Granulomas were observed in the lungs of three patients, in the liver of one patient, and in the skin of one patient. Cultures revealed Mycobacterium tuberculosis in two patients, Mycobacterium fortuitum in two patients, and Mycobacterium kansasii in one patient. In the six patients treated with antimycobacterial therapy in either the pretransplant or posttransplant period, complete resolution of the infection was achieved. Pretransplant chest radiograph abnormalities suggesting mycobacterial infections should be aggressively evaluated in these immunocompromised hosts. Prophylaxis should be considered in marrow graft recipients with a well-established history of inadequately treated tuberculosis, previous Bacille Calmette-Guerin immunotherapy, known family contacts, recent skin test conversion, or past skin test positivity.     

Hand infections caused by delayed inoculation of Vibrio vulnificus: does human skin serve as a potential reservoir of vibrios?

Vibrio vulnificus may cause severe soft tissue infections of the upper extremity. This pathogen usually gains access to soft tissues either by direct inoculation through a penetrating injury by an infected marine animal or by exposing abraded skin to contaminated water. We report five patients with Vibrio vulnificus hand infections following superficial hand injuries incurred within 24 hours after uneventful handling of fish. This clinical observation, together with the fact that the physiologic characteristics of human sweat simulate the natural environment of the Vibrio vulnificus, support the assumption that human skin may serve as a reservoir for Vibrios. The anamnesis in patients presenting with hand infection should essentially include an inquiry regarding recent, albeit uneventful, fish handling.     

Pneumonectomy for nontuberculous mycobacterial infections

Background

Pneumonectomy is considered in the treatment of nontuberculous mycobacterial infections when an entire lung is affected. However, this procedure carries high morbidity. We report on our experience in using pneumonectomy for treating patients with nontuberculous mycobacterial infections.

Methods

Between 1983 and 2002, 53 patients infected with nontuberculous mycobacteria underwent 55 pulmonary resections. Of these patients, 11 (3 men, 8 women) underwent pneumonectomy (5 right, 6 left). Median age was 57 years (range, 43 to 69 years). Mycobacterium avium complex disease occurred in 10 patients and Mycobacterium abscessus disease in 1. Indications for pneumonectomy included multiple cavities in one lung and destruction of an entire lung. The bronchial stump was covered with a latissimus dorsi muscle flap in 7 patients and with an intercostal pedicle flap in 2.

Results

Operating time ranged from 142 to 477 minutes (median, 360 minutes). The median intraoperative blood loss was 555 mL (range, 130 to 1,245 mL). There was no operative mortality. Bronchopleural fistula occurred in 3 patients. All fistulas were observed after right pneumonectomy, and were treated by reclosure of the bronchus. Empyema occurred in 1 patient, who was treated with irrigation. All patients achieved sputum-negative status after surgery. Two late deaths occurred. One patient died of respiratory failure 11 months after surgery. A second patient, the only patient who had recurrent disease, died of respiratory failure 4 years postoperatively.

Conclusions

Despite bronchial stump protection, right pneumonectomy carries a risk for bronchopleural fistula. Nonetheless, pneumonectomy can result in high cure rates in patients with nontuberculous mycobacterial infections.     

Spindle cell tumors associated with mycobacteria in lymph nodes of HIV-positive patients: 'Kaposi sarcoma with mycobacteria' and 'mycobacterial pseudotumor'.

Patients infected with HIV often have unusual manifestations of common infections and neoplasms. One such example is "mycobacterial pseudotumor," an exuberant spindle cell lesion induced in lymph nodes by mycobacteria. Kaposi sarcoma also produces a spindle cell proliferation in lymph nodes of HIV-positive patients. These two entities must be differentiated from one another because of differences in treatment and prognosis. We report here, however, three cases of intranodal Kaposi sarcoma with simultaneous mycobacterial infection, the occurrence of which has not been clearly documented. For comparison, we also studied three cases of mycobacterial pseudotumor, of which 14 cases have been described to date. There was considerable histologic overlap between these two lesions. Acid-fast bacilli were present in all cases, predominantly in the more epithelioid histiocytes in the cases of Kaposi sarcoma, and in spindle and epithelioid cells in the cases of mycobacterial pseudotumor. The morphologic features that favored Kaposi sarcoma over mycobacterial pseudotumor were the prominent fascicular arrangement of spindle cells and slitlike spaces, the lack of granular, acidophilic cytoplasm, and the presence of mitoses. Immunohistochemistry was a reliable adjunct study in the differential diagnosis, as the spindle cells in mycobacterial pseudotumor were positive for S-100 protein and CD68 whereas those of Kaposi sarcoma were CD31- and CD34-positive but negative for S-100 protein and CD68. Awareness that Kaposi sarcoma may coexist with mycobacterial infection in the same biopsy specimen is important because these lesions may be misdiagnosed as mycobacterial pseudotumor. The clinical impact of distinguishing between Kaposi sarcoma with mycobacteria and mycobacterial pseudotumor is significant because the presence of Kaposi sarcoma alters treatment and prognosis.     

Atypical mycobacterial infections of the hand: report of eight cases and literature review

INTRODUCTION: Atypical mycobacteria are an uncommon cause of hand infections in immunocompetent patients. Diagnosis is often delayed, with consequent increased morbidity. Better awareness would allow earlier diagnosis and treatment. MATERIAL AND METHODS: Eight patients with atypical mycobacterial hand infections treated in our department over a 21 year period have been retrospectively identified. Their charts have been searched for the general characteristics of these infections, treatment and outcome. Our findings have been compared to the data collected from a literature review. RESULTS: These pathogens have caused soft tissue infections in otherwise healthy patients. Clinical signs were those of chronic finger or wrist synovitis or skin granulomas. Carpal tunnel syndrome was a common finding. Diagnosis relied on surgical biopsy. Germ identification required specific incubation temperature and media. Antibiotics and synovectomy have been the mainstay of therapy. DISCUSSION: In a patient with achronic, relapsing, superficial or deep skin infection or tenosynovitis, aquatic and farm exposures are important anamnestic keys to diagnosis. Extensive synovectomy is both diagnostic and therapeutic. Specific cultures should be ordered without delay. Oral pharmacotherapy should be initiated upon clinical suspicion.     

Atypical mycobacterial spondylitis in HIV-negative patients identified by genotyping

Non-tuberculous mycobacterial infections pose a significant diagnostic and therapeutic challenge. We report two cases of such infection of the spine in HIV-negative patients who presented with deformity and neurological deficit. The histopathological features in both specimens were diagnostic of tuberculosis. The isolates were identified as Mycobacterium intracellulare and M. fortuitum by genotyping (MicroSeq 16S rDNA Full Gene assay) and as M. tuberculosis and a mycobacterium other than tuberculosis, respectively, by culture. There is a growing need for molecular diagnostic tools that can differentiate accurately between M. tuberculosis and atypical mycobacteria, especially in regions of the developing world which are experiencing an increase in non-tuberculous mycobacterial infections.     

Postoperative infection after duraplasty with expanded polytetrafluoroethylene sheet

Dural reconstruction is a significant problem in many cases of decompressive craniotomy and dural defect. Expanded polytetrafluoroethylene (ePTFE) sheet have been used as a dura mater substitute for duraplasty. The outcomes of 83 consecutive patients at our institution were reviewed who underwent external decompression and closure with the ePTFE sheet between August 1995 and December 2000. Eight cases of infection occurred. Seven patients had infection with subdural empyema after cranioplasty with autologous bone. Three patients improved after removal of only the infected bone. One patient improved after removal of the infected bone and ePTFE sheet. One patient experienced wound infection after the original operation. Four patients subsequently developed local and severe inflammation with skin erythema until the ePTFE sheet was removed. Four patients had severe recurrent infections which required subsequent therapy such as vascularized free rectus abdominis muscle flap transfer. Duraplasty with ePTFE sheet might promote infection and poor circulation in the skin flap. The ePTFE sheet should be removed at an early stage in a patient with infection.