[An epidemiological study on the ecological environment related to Nontuberculous mycobacteria in Shenzhen city of Guangdong province]

OBJECTIVE

To investigate the distribution of Nontuberculous mycobacteria in the environment of Shenzhen city and its related sensitivity to drugs.

METHODS

145 samples in the environment of Shenzhen city were collected and the samples were isolated, identified and its drug sensitivity were detected according to the "Procedure of Bacteriological Determination Regulation for Tuberculous Diagnosis", issued in 1995 by the Antituberculosis Association of China.

RESULTS

All together, 53 strains of Mycobacteria were detected from the 145 sample, including 6 of them isolated from the polluted water in the hospital before disinfected, 4 from the polluted water in the hospital after disinfected, 4 from the dirt of air condition in the hospital, 34 from the polluted water in the residential area, 3 from the ocean water and 2 from the fountain. M. nonchromogenicum, M. avium, M. fortuitum, M. gordonae, M. genavense, M. chelonae and M. intracellulare were identified.

CONCLUSION

Nontuberculous mycobacteria seemed to widely exist in the environment of Shenzhen city and the ratio of drug-resistant was high. Attention should be paid to the influence of Nontuberculous mycobacteria on humans in order to formulate effective control measure.

Infection withMycobacterium simiaecomplex in four captive Micronesian kingfishers

CASE DESCRIPTION

4 captive adult Micronesian kingfishers (Halcyon cinnamomina cinnamomina) at 3 zoologic institutions were examined routinely or because of dyspnea or lethargy.

CLINICAL FINDINGS

All birds had marked hepatomegaly. Two birds had dyspnea caused by compression of air sacs by the enlarged liver, and 1 bird had generalized weakness and lethargy. Three birds had distended coelomic cavities, and 3 birds were thin or had lost weight. There were no consistent abnormalities in blood analytes. Results of most ancillary diagnostic tests such as acid-fast staining of cloacal or fecal swab specimens and culture of feces for acid-fast bacteria were negative. Results of examination of hepatic biopsy specimens in 2 of 4 birds were suggestive of mycobacteriosis.

TREATMENT AND OUTCOME

3 birds died or were euthanized soon after diagnosis. One kingfisher was isolated and monitored for 4 months without treatment and died during anesthesia for disease monitoring. Postmortem histologic examination revealed histiocytic hepatitis and acid-fast bacteria in all 4 birds. Bacteriologic culture of liver specimens yielded Mycobacterium simiae complex in all 4 birds.

CLINICAL RELEVANCE

Infection with M simiae complex should be considered in ill Micronesian kingfishers, and further monitoring is warranted to determine whether this is an emerging pathogen in this species.

Mycobacterium tuberculosis infection in First Nations preschool children in Alberta: implications for BCG (bacille Calmette-Guérin) vaccine withdrawal

BACKGROUND

On April 1, 2004, BCG (bacille Calmette-Guérin), a tuberculosis (TB) control vaccine, was discontinued in all but four high-risk communities in Alberta. To confirm the safety of vaccine withdrawal, and for future planning, the annual risk of infection (ARI) was determined in preschool First Nations children.

METHODS

First Nations children born into reserve communities in Alberta between April 1, 1998 and March 31, 2004, and still living on reserve in 2004-2005, were identified. Health centre TB histories were validated by cross-referencing the birth cohort with the provincial TB Registry. Children that were not BCG vaccinated and not known to be tuberculin skin test (TST) positive underwent a TST. Birth cohort children were grouped as follows: (i) BCG vaccinated; (ii) BCG non-vaccinated, no TST; (iii) BCG non-vaccinated, TST; (iv) BCG vaccination status unknown. The ARI was calculated and the age and community characteristics of the groups were compared.

RESULTS

There were 8447 children in the 6-year birth cohort, 4699 (55.6%) vaccinated, 2696 (31.9%) non-vaccinated, and 1052 (12.5%) whose vaccination status was unknown. Of the non-vaccinated children, 1921 (71.3%) were tested and only 2 were TST positive. No other TST positive, BCG non-vaccinated children were identified in the TB Registry cross-match. The prevalence of infection in 2004-2005 was 0.1% and the ARI was 0.03%. The community risk of TB exposure was comparable in tuberculin-tested and non-tested BCG non-vaccinated children.

CONCLUSION

In low BCG-uptake First Nations communities in Alberta, the ARI is low and it is safe to withdraw BCG.

Disseminated Mycobacterium bovis infection after BCG vaccination

The Calmette-Güerin vaccine (BCG) is administered to all the newborns in Iran in order to prevent tuberculosis. Complications of this vaccine are uncommon. We report disseminated BCG disease in 17 patients less than 10 years old. This is a retrospective study of total of 17 cases who were admitted in Children Medical Center Hospital with systemic syndrome compatible with Mycobacterium disease with evidence of histopathologic demonstration of acid-fast bacilli during 1995-2004. Fourteen cases occurred in children younger than 1 year old. Nine patients were female. Ten of the 17 total cases were associated with an immune deficiency including severe combined immunodeficiency, chronic granulomatous disease and cell mediated immune defect. Response to therapy was ineffective and 10 of them (58.8%) died. Disseminated BCG disease is an uncommon but devastating complication of vaccination that should be considered in the appropriate clinical setting. Immune-compromised infants are at greatest risk and they respond poorly to standard therapies.

Environmental mycobacteria in soil and water on beef ranches: association between presence of cultivable mycobacteria and soil and water physicochemical characteristics

Exposure to environmental mycobacteria has been reported to be a factor contributing to false-positive results on bovine serological tests detecting antibodies to Mycobacterium avium subsp. paratuberculosis (Mptb). This study was conducted to investigate the association between recovery of mycobacteria from the environment of cattle and both (i) historically high or low seroprevalence to Mptb, and (ii) soil and water physicochemical characteristics. Eighty-two samples (soil and water) from nine beef cattle ranches in South-central and South Texas were assessed for the presence of mycobacteria. Twelve mycobacterial species were cultured from soil and water from four herds; no Mptb were detected in environmental samples. A positive culture of environmental mycobacteria from soil was significantly associated with lower pH and calcium as well as higher iron, zinc and manganese contents. Beef cattle are likely to be exposed to environmental mycobacteria that may contribute to false-positive results on ELISAs for Mptb infection. Exposure rates to these mycobacteria likely vary across small geographical areas and may be related to soil and/or water physicochemistry.

Identification of an emerging pathogen, Mycobacterium massiliense, by rpoB sequencing of clinical isolates collected in the United States

Mycobacterium massiliense is a rapidly growing mycobacterium that is indistinguishable from Mycobacterium chelonae/M. abscessus by partial 16S rRNA gene sequencing. We sequenced rpoB, sodA, and hsp65 genes from isolates previously identified as being M. chelonae/M. abscessus and identified M. massiliense from isolates from two patients with invasive disease representing the first reported cases in the United States.

Asociación Micobacterias-VIH/SIDA en Pacientes Atendidos en un Hospital Universitario en Bogotá, Colombia

OBJECTIVE

Evaluating the frequency of mycobacterium infection in an HIV-positive population and its influence on medium-term survival, along with clinical and epidemiological factors associated with co-infection.

METHODS

Several clinical specimens were studied for mycobacteria in a sample of 92 HIV+ patients at the San Juan de Dios teaching-hospital in Bogota, Colombia, during 1996. Factors associated with infection were measured using a prevalence ratio (PR), CI=95%, and logistic regression was used in the multivariable models. The likelihood of survival for three months was measured using Kaplan-Meir curves and factors associated with survival were assessed using Rate ratios and Cox's model.

RESULTS

Eight percent of the patients had tuberculosis and 6% of them were found to be infected with atypical mycobacterium. Mycobacterium avium complex (MAC) was the most frequent species, followed by M. fortuitum and M. chelonae. Mixed infections with M. tuberculosis and MAC were diagnosed in one patient and two different species of atypical mycobacterium were isolated in other two cases. Patients suffering from tuberculosis and stages III or IV HIV infection had a 16% survival rate.

CONCLUSIONS

Tuberculosis-HIV/AIDS frequency and atypical Mycobacterium-HIV/AIDS' association were very similar. The most frequently isolated atypical mycobacterium specie in this study was MAC. Survival rate was lower for patients infected by M. tuberculosis and even lower when a multi-resistant strain was involved. The most important clinical factor associated with M. tuberculosis was the presence of fever and loss of weight with mycobacterial infection. Blood provided the best samples for isolating mycobacteria.

Adenitis por micobacterias no tuberculosas

OBJECTIVE

To study the clinical features, epidemiology and outcome of nontuberculous mycobacterial lymphadenitis (NTML).

METHODS

A retrospective study was performed on 54 patients under 14 years old diagnosed with atypical mycobacterial lymphadenitis between 1987 and 2004. Inclusion criteria were: (i) positive polymerase chain reaction (PCR) test or culture; (ii) positive sensitin skin test 6 mm above Mantoux; (iii) histopathologic features compatible with mycobacterial infection and/or positive direct smear for acid-fast bacilli, Mantoux reaction less than 15 mm, a normal chest radiograph, absence of exposure to an adult with tuberculosis, negative Mantoux test reactions in family members, and exclusion of other causes of granulomatous adenitis.

RESULTS

Fifty-four patients were included in the study. The number of NTML cases increased notably from 1996, coinciding with a decrease in cases of tuberculous adenitis. The mean age was 35 months (range: 14 months-6 years). Submandibular nodes were involved in 22 of 63 cases of adenitis (34.9%) and cervical nodes were involved in 21 (33.3%). In 8/42 patients (19%) the tuberculin skin test was larger than 10 mm. Cultures were positive in 52.9% of the cases (18/34) and PCR in 53.3% (8/15). The most frequently isolated mycobacteria was Mycobacterium avium (61%). Therapy failed in 8/21 patients receiving antibiotics (38%), in 10/13 patients with drainage alone (77%) and in none of the patients who underwent surgery (8/8).

CONCLUSIONS

Nontuberculous mycobacterial adenitis has become more frequent in our hospital since 1996. Cultures do not always allow isolation of mycobacteria and the Mantoux test frequently yields false positive results, thus hampering diagnosis. The most effective treatment was surgical excision. Nevertheless, when the surgical approach is difficult or there is postoperative recurrence, pharmacological treatment can be useful.

Isolation prevalence of pulmonary non-tuberculous mycobacteria in Ontario, 1997 2003

BACKGROUND

The prevalence of pulmonary non-tuberculous mycobacteria (NTM) infection is reportedly increasing. A study was undertaken of the "isolation prevalence" of pulmonary NTM in Ontario, Canada between 1997 and 2003 and the frequency of pulmonary NTM "disease".

METHODS

In a retrospective cohort, the "isolation prevalence" was studied by reviewing all positive NTM culture results from the Tuberculosis and Mycobacteriology Laboratory, Ministry of Health and Long-Term Care in Toronto from 1997 to 2003. This laboratory identifies at least 90% of NTM isolates in Ontario, Canada. Prevalence was compared between years using a negative binomial model. To study the frequency of "disease" (defined by American Thoracic Society criteria), the records of patients who had an isolate in 2003 and had been assessed at our hospital were reviewed.

RESULTS

22,247 pulmonary isolates were obtained from 10,231 patients. The "isolation prevalence" of all species (excluding Mycobacterium gordonae) was 9.1/100,000 in 1997, rising to 14.1/100,000 by 2003 (p<0.0001) with a mean annual increase of 8.4%. Similar increases were observed for individual species. 200 patients assessed at our institution were studied using American Thoracic Society criteria for "disease". Microbiological criteria were fulfilled by 37%. Of patients with adequate data, 74% fulfilled clinical criteria, 77% fulfilled radiological criteria and 33% fulfilled all criteria.

CONCLUSIONS

The "isolation prevalence" of pulmonary NTM has significantly and rapidly increased in Ontario; a sizeable proportion of patients are likely to have "disease".

The new mycobacteria: an update

The continuous evolution of mycobacterial taxonomy may represent a source of confusion for laboratories and clinicians. Apart from the obvious pathogenic strains of the Mycobacterium tuberculosis complex, Mycobacterium leprae and Mycobacterium ulcerans, the role of other mycobacteria may be associated with varying conditions ranging from contamination to specific disease processes. Of the more than 120 mycobacterial species recognized currently, very few have not been reported as pathogenic in humans or animals. Although the attempt to keep pace with the steadily increasing number of mycobacterial species seems hopeless, a careful review of the recent literature relevant to the newly described species may be advantageous. The aim of this present update is to provide epidemiological and clinical information along with major phenotypic and genotypic characteristics of the species described in the last 3 years.

Prevalence of non-tuberculous mycobacteria in a hospital environment

In recent years, non-tuberculous mycobacteria (NTM) have emerged as an important cause of opportunistic nosocomial infections but there is little known about the isolation and identification of NTM in Korea. The aim of this study was to assess the prevalence of NTM in the hospital environment and identify the species. A total of 150 samples were collected from different parts of the hospital. NTM were isolated and identified by restriction fragment length polymorphism analysis of the gene encoding rpoB and partial sequencing analysis of hsp65 and rpoB. In this study, 60 strains of NTM were isolated from 50 of the 150 samples. Half of the tap water samples (50 of 100) were positive for mycobacteria. An estimated 73.3% of the isolates were saprophytic, 21.7% were potentially pathogenic and 5% were unidentified. The presence of NTM in hospital tap water is not uncommon. Such water isolates might cause true nosocomial infection in immunocompromised patients, in addition to the risk of false-positive culture results.

A low incidence of nontuberculous mycobacterial infections in pediatric hematopoietic stem cell transplantation recipients

Hematopoietic stem cell transplantation (HSCT) is being used to treat a wide spectrum of clinical disorders but opportunistic infection remains an important factor determining outcomes for these patients. Nontuberculous mycobacterial (NTM) infections are being reported more frequently in HSCT recipients and the incidence of NTM infections in adult recipients is reported to be 0.4%-4.9%. However, the incidence and severity of NTM infections are less well described in pediatric HSCT recipients. Centers for Disease Control and Prevention guidelines were used to define definite and probable NTM infection among 132 children undergoing 169 HSCT between January 2000 and December 2004 at our institution. NTM infection was diagnosed in 5 of 132 pediatric recipients (3.8%). There were no NTM infections diagnosed in the autologous HSCT recipients and the incidence of NTM in allogeneic HSCT recipients was 6.4% (95% confidence interval, 0.8-11.9). The mean age of the HSCT recipients who developed NTM infections was 8 years (range, 2-19 years); 3 were male and 2 were female. Four conditioning regimens included alemtuzumab and 3 had antithymocyte globulin. Of the 5 patients with NTM infections, 2 met the criteria for definite infection and 3 for probable infection. Of the 2 patients with definite NTM infection, 1 had disseminated disease with Mycobacterium avium complex and the other had Mycobacterium chelonae catheter-related bloodstream infection. The probable NTM infections were 1 skin infection with Mycobacterium kansasii and 2 lower respiratory tract infections with M avium complex. Median time to NTM infection was 115 days (range, 14-269 days) after HSCT. Two patients had graft-versus-host disease at the time of NTM infection. All 5 patients received 3-4 antimycobacterial drugs and all NTM infections resolved. In summary, the incidence of NTM infection in pediatric HSCT recipients appears similar to that described in adult HSCT recipients and the outcome appears to be excellent with the proper antibiotic therapy. The increased use of anti-T cell antibodies appears to be associated with an increased risk of NTM infections in pediatric HSCT recipients. Multicenter studies are needed to identify the risk factors, early diagnostic criteria, and optimal therapy.

An outbreak of mycobacteriosis in Gouldian finches caused by Mycobacterium peregrinum

An outbreak of mycobacteriosis was detected in an aviary containing Gouldian finches (Erythrura gouldiae) and golden shouldered parrots (Psephotus chrysopterygius). Affected birds developed granulomatous lesions, usually of the liver and intestine. Mycobacterium peregrinum, a species of the Mycobacterium fortuitum group, was cultured on pooled samples of intestinal tract from 31 euthanized finches. These rapid-growing mycobacteria are saprophytic organisms that are generally not associated with clinical disease in immunocomponenet hosts. This is the first report of mycobacteriosis in finches implicating M peregrinum as a causative agent.

[The centralized mycobacteriological laboratory is a necessary component of a phthisiological service in large towns of Russia]

The paper presents the main points of the authors' own concept of the centralization of mycobacteriological service in large towns of the Russian Federation. The main points of step-by-step organizational and methodological measures required to solve this problem are described in detail. Consecutive measures to realize the proposed mycobacteriological service centralization model originated in January 2004 on a model of the Moscow Eastern Administrative District with 1380 thousand inhabitants are described.

Isolation of non-tuberculous mycobacteria in children investigated for pulmonary tuberculosis

Objective

To evaluate the frequency and clinical significance of non-tuberculous mycobacteria (NTM) isolates among children investigated for pulmonary tuberculosis in a rural South African community.

Methods

Children were investigated for pulmonary tuberculosis as part of a tuberculosis vaccine surveillance program (2001–2005). The clinical features of children in whom NTM were isolated, from induced sputum or gastric lavage, were compared to those with culture-proven M. tuberculosis.

Results

Mycobacterial culture demonstrated 114 NTM isolates from 109 of the 1,732 children investigated, a crude yield of 6% (95% CI 5–7). The comparative yield of positive NTM cultures from gastric lavage was 40% (95% CI 31–50), compared to 67% (95% CI 58–76) from induced sputum. 95% of children with NTM isolates were symptomatic. Two children were HIV-infected. By contrast, M. tuberculosis was isolated in 187 children, a crude yield of 11% (95% CI 9–12). Compared to those with culture-proven M. tuberculosis, children with NTM isolates were less likely to demonstrate acid-fast bacilli on direct smear microscopy (OR 0.19; 95% 0.0–0.76). Children with NTM were older (p<0.0001), and more likely to demonstrate constitutional symptoms (p = 0.001), including fever (p = 0.003) and loss of weight or failure to gain weight (p = 0.04), but less likely to demonstrate a strongly positive tuberculin skin test (p<0.0001) or radiological features consistent with pulmonary tuberculosis (p = 0.04).

Discussion

NTM were isolated in 6% of all children investigated for pulmonary tuberculosis and in more than one third of those with a positive mycobacterial culture. NTM may complicate the diagnosis of PTB in regions that lack capacity for mycobacterial species identification. The association of NTM isolates with constitutional symptoms suggestive of host recognition requires further investigation.

Skin and soft tissue infections due to rapidly growing mycobacteria: comparison of clinical features, treatment, and susceptibility

OBJECTIVE

To compare the demographics, clinical features, susceptibility patterns, and treatment for skin and soft tissue infections due to Mycobacterium fortuitum and Mycobacterium chelonae or Mycobacterium abscessus.

DESIGN

Retrospective medical record review.

SETTING

Mayo Clinic, Rochester, Minn.

PATIENTS

All patients seen at our institution with a positive culture for M chelonae, M abscessus, or M fortuitum from skin or soft tissue sources between January 1, 1987, and October 31, 2004.

MAIN OUTCOME MEASURES

Patient demographics, clinical characteristics, therapeutic data, microbiological data, and outcomes.

RESULTS

The medical records of 63 patients with skin or soft tissue infections due to rapidly growing mycobacteria were reviewed. Patients with M chelonae or M abscessus were older (61.5 vs 45.9 years, P<.001) and more likely to be taking immunosuppressive medications (60% vs 17%, P = .002) than patients with M fortuitum. Mycobacterium fortuitum tended to manifest as a single lesion (89% vs 38%, P<.001), while most M chelonae or M abscessus manifested as multiple lesions (62% vs 11%, P<.001). More patients with M fortuitum had a prior invasive surgical procedure at the infected site (56% vs 27%, P = .04). Patients with multiple lesions were more likely to be taking immunosuppressive medications than those with single lesions (67% vs 30%, P = .006). Seven patients failed treatment, several of whom were immunocompromised and had multiple comorbidities.

CONCLUSIONS

Skin and soft tissue infections due to rapidly growing mycobacteria are associated with systemic comorbidities, including the use of immunosuppressive medications. There are significant differences in the demographic and clinical features of patients who acquire specific organisms, including association with immunosuppression and surgical procedures.

Nontuberculous mycobacterial infections in King Chulalongkorn Memorial Hospital

BACKGROUND

Nontuberculous mycobacteria (NTM) can cause infections in both human immunodeficiency virus (HIV)-infected and HIV-noninfected patients. The incidence of NTM infections has been increasing since the acquired immunodeficiency syndrome (AIDS) epidemics. However, the epidemiologic and clinical data of NTM infections in Thailand are limited.

OBJECTIVE

Determine the epidemiology, clinical manifestations, treatment, and outcome of NTM infections in King Chulalongkorn Memorial Hospital from January 2000 to December 2003.

MATERIAL AND METHOD

One hundred and fourteen patients had positive NTM cultures; however, complete medical records were available in only 103 (90.3%) patients.

RESULTS

There were 71 (68.9%) HIV-infected patients, and 38 (87%) of them had the CD4 counts of < 200 cells/microL (range 4-360). Among HIV-infected patients, the most common previous opportunistic infections included tuberculosis (36.6%), Pneumocystis jirovecii pneumonia (25.3%), cryptococcal meningitis (15.5%), penicilliosis (5.6%), and cytomegalovirus infection (5.6%). Most patients presented with prolonged fever (67%), chronic cough (54.4%), lymphadenopathy (52.4%), weight loss (50.5%), or chronic diarrhea (31%). The clinical manifestations included disseminated (17.4%) and localized (82.6%) infections. The localized infection included pulmonary infection (82.3%), followed by gastrointestinal infection (34.1%), skin infection (12.9%), lymphadenitis (8.2%), genitourinary tract infection (2.4%), central nervous system infection (2.4%), and keratitis (1.2%). Mycobacterium avium complex (MAC) was the predominant species (48.5%), followed by M. kansasii (19.4%), and rapidly growing mycobacteria (16.4%). Diffuse reticular infiltration was most commonly observed on chest radiography (53.4%). Abnormal laboratory findings included anemia (48.5%), hyponatremia (42.7%), and elevated alkaline phosphatase (39.8%). The overall mortality rate was 34.8% (45.9% and 11.1% in HIV- and HIV-noninfected patients).

CONCLUSION

A diagnosis of NTM infection requires a high index of suspicion in patients especially with AIDS or immunocompromised status who present with prolonged fever, with or without organ-specific symptoms and signs. Therefore, clinical specimens must be sent for mycobacterial cultures for a definite diagnosis, a determination of the species of NTM, and an appropriate management. In addition to four standard antituberculous drugs, clarithromycin should be added for the treatment of MAC in patients with AIDS who presented with disseminated opportunistic infections before obtaining the microbiologic results.

Prevalence of viral and mycobacterial co-infections in perinatally HIV-infected children

The progression of HIV disease may be affected by co-infection with other viruses. This study investigates the prevalence of Epstein-Barr virus (EBV); cytomegalovirus (CMV); herpes simplex virus (HSV) types 1 and 2; hepatitis A, B, and C (HA, HB, HC); and tuberculosis in perinatally HIV-infected children. Electrochemiluminescence Immunoassay (EIA) against EBV, CMV, HSV 1 and 2, HAV HBV HCV, and skin testing with purified protein derivative was performed on 45 perinatally HIV-infected children. CMVwas positive in 51%, EBVin 93.3%, HSV-1 in 62.2%, HSV-2 in 48.9%, HAV in 15.6%, HBVand HCV in 6.7% and PPD in 0%. HSV-2 prevalence was higher in females and Hispanics. The prevalence of CMV, EBV HSV-1, and tuberculosis was equivalent to rates reported in the general population. Prevalence of HSV-2 was significantly higher than in the general population (p < 0.001). Higher rates of HSV-2 infection and hepatitis may be secondary to high maternal co-infection rate and subsequent vertical transmission.

INFECTIONS CAUSED BY MYCOBACTERIUM AVIUM SUBSPECIES AVIUM, HOMINISSUIS, AND PARATUBERCULOSIS IN FREE-RANGING RED DEER (CERVUS ELAPHUS HIPPELAPHUS) IN AUSTRIA, 2001–2004

Between 2001 and 2004, 14 Austrian free-ranging red deer (Cervus elaphus hippelaphus) infected by Mycobacterium avium species were observed. Eight of the cases were from different geographical regions, and six originated from the same hunting area. The affected animals had signs of diarrhea, severe weight loss, and emaciation. On post-mortem examination, lymphadenitis associated with grossly enlarged mesenteric lymph nodes as well as multiple caseous or purulent nodular lesions in the thickened wall of the intestines were present in all animals. In 10 cases M. avium subsp. avium and in four cases M. a. hominissuis were isolated. In three red deer, a mixed infection with M. a. hominissuis and M. a. paratuberculosis was evident. Typing of M. a. avium and M. a. hominissuis isolates was performed by polymerase chain reaction (PCR) detection of insertion sequence IS901 and the virulence-associated macrophage-induced gene (mig), inverted repeat (IR) typing (IS1245/IS1311), and random amplified polymorph DNA (RAPD) analysis. While all M. a. avium and M. a. hominissuis contained the mig gene, IS901 was detected only in M. a. avium. The prevalence of IS901-positive isolates correlated well with the geographic location of affected animals. The IS901-containing isolates were shown to be genotypically closely related, as they exhibit similar patterns in IR-typing and in RAPD analysis. In contrast, IS901-negative isolates (M. a. hominissuis) displayed distinct profiles in both molecular systems.

The sonographic characteristics of nontuberculous mycobacterial cervicofacial lymphadenitis in children

BACKGROUND

Nontuberculous mycobacteria (NTM) are a common cause of chronic cervicofacial lymphadenitis in young children. The differential diagnosis includes other infections, lymphoepithelial cysts and malignancies.

OBJECTIVE

To assess the sonographic findings of NTM cervicofacial lymphadenitis in children.

MATERIALS AND METHODS

We analysed the sonograms of cervicofacial lymph nodes of 145 children with microbiologically proven NTM lymphadenitis.

RESULTS

The size of the involved lymph nodes ranged from 1.9 cm to 4.4 cm. Most of the NTM patients (85%) presented in a stage of lymph node fluctuation with violaceous skin discoloration. On sonography, marked decreased echogenicity was seen in all cases. In 133 of the patients (92%) liquefaction with intranodal cystic necrosis, nodal matting and adjacent soft-tissue oedema were present. 66 children received antibiotic treatment, and the other children underwent surgical excision of the involved lymph nodes. In 69% of the patients successfully treated with antibiotics, multiple intranodal calcifications were present on sonography after 1 year.

CONCLUSIONS

Sonographic findings can provide additional diagnostic clues for NTM lymphadenitis in childhood. A marked decrease of echogenicity in the early stages, with intranodal liquefaction in the advanced stages, are universal features, albeit not entirely specific. Multiple intranodal calcifications are rather characteristic of end-stage mycobacterial infection.

An outbreak of Mycobacterium jacuzzii infection following insertion of breast implants

BACKGROUND

Surgical wound infections caused by rapidly growing mycobacteria developed in 15 women after insertion of breast implants from August to November 2003 at a single medical center.

METHODS

A case-control study was conducted that included the identified patients, as well as women who underwent breast operations at the same center who did not develop infections. The study was accompanied by an extensive environmental investigation. Isolates were identified by standard bacteriological methods and by comparison of their 16S rRNA, HSP65, RPOB, SODA, and RECA gene sequences. Isolates were compared by random amplified polymorphic DNA analysis and by pulsed-field gel electrophoresis.

RESULTS

The risk factors for infection included surgery performed by 1 specific surgeon (odds ratio, 21.3; 95% confidence interval, 3.64-125.6). Identical strains of mycobacteria were isolated from the infected wounds of the patients; from the eyebrows, hair, face, nose, ears, and groin of this particular surgeon; and from this surgeon's outdoor whirlpool. The isolates exhibited a biochemical profile overlapping that of Mycobacterium wolinskyi, but their sequences of 16S rRNA and HSP65, RPOB, SODA, and RECA genes differed. We propose the name "Mycobacterium jacuzzii" for this new species. DNA fingerprints of cultured isolates from the surgical wounds, areas of the surgeon's body that grow hair, and the surgeon's whirlpool were identical. When the surgeon discontinued his use of the whirlpool and began cleaning the hairy areas of his body with a shampoo containing triclosan, the outbreak ended.

CONCLUSIONS

This outbreak brings to light the possibility of the colonization of human skin and human-to-human transmission of environmental mycobacteria during surgery that involves implant insertion.

Globally distributed mycobacterial fish pathogens produce a novel plasmid-encoded toxic macrolide, mycolactone F

Mycobacterium ulcerans and Mycobacterium marinum are closely related pathogens which share an aquatic environment. The pathogenesis of these organisms in humans is limited by their inability to grow above 35 degrees C. M. marinum causes systemic disease in fish but produces localized skin infections in humans. M. ulcerans causes Buruli ulcer, a severe human skin lesion. At the molecular level, M. ulcerans is distinguished from M. marinum by the presence of a virulence plasmid which encodes a macrolide toxin, mycolactone, as well as by hundreds of insertion sequences, particularly IS2404. There has been a global increase in reports of fish mycobacteriosis. An unusual clade of M. marinum has been reported from fish in the Red and Mediterranean Seas and a new mycobacterial species, Mycobacterium pseudoshottsii, has been cultured from fish in the Chesapeake Bay, United States. We have discovered that both groups of fish pathogens produce a unique mycolactone toxin, mycolactone F. Mycolactone F is the smallest mycolactone (molecular weight, 700) yet identified. The core lactone structure of mycolactone F is identical to that of M. ulcerans mycolactones, but a unique side chain structure is present. Mycolactone F produces apoptosis and necrosis on cultured cells but is less potent than M. ulcerans mycolactones. Both groups of fish pathogens contain IS2404. In contrast to M. ulcerans and conventional M. marinum, mycolactone F-producing mycobacteria are incapable of growth at above 30 degrees C. This fact is likely to limit their virulence for humans. However, such isolates may provide a reservoir for horizontal transfer of the mycolactone plasmid in aquatic environments.

Emergence of disseminated infections due to nontuberculous mycobacteria in non-HIV-infected patients, including immunocompetent and immunocompromised patients in a university hospital in Taiwan

OBJECTIVES

Although disseminated nontuberculous mycobacteria (NTM) infection has been increasingly reported in patients with AIDS, this condition is still considered rare in non-HIV-infected patients.

METHODS

We retrospectively reviewed the medical records of non-HIV-infected patients treated at National Taiwan University Hospital from January 1997 to December 2004 to search for epidemiological trends in disseminated NTM infection. Data analyzed included etiology, demographic characteristics, underlying disease, initial symptoms and signs, treatment, and outcomes.

RESULTS

Disseminated NTM infections occurred in 15 non-HIV-infected patients during the study period. The mean age of these patients was 51 years (range 13-80). Among these patients, eight were males, and eight had various immunocompromised conditions. Fever was an initial presentation in 12 patients (80%). Diagnosis was made by positive blood (seven patients) or bone marrow culture (five patients) in the majority (73%) of patients. Infectious etiologies included Mycobacterium avium complex (MAC) in eight, rapidly growing mycobacteria (RGM) in four and Mycobacterium kansasii in three. The mean time from initial presentation to initiation of anti-NTM therapy was 130 days (ranged from 9 days to 17 months). Mortality was highest in patients with M. kansasii (100%), followed by RGM (25%) and MAC (12.5%).

CONCLUSIONS

Although disseminated NTM infection is an emerging condition among patients without HIV infection, it is a condition which is associated with immune deficiency. A high level of clinical suspicion should be maintained for avoiding delayed diagnosis, especially in patients with underlying immunosuppression. Blood culture might play an important role in the early diagnosis of disseminated NTM disease. Early diagnosis can lead to appropriate diagnosis and reduce mortality.

Environmental risk factors for infection with Mycobacterium avium complex

Infection with Mycobacterium avium complex is acquired from the environment, but risk factors for M. avium complex infection and disease are poorly understood. To identify risk factors for infection, the authors performed a 1998-2000 cross-sectional study in western Palm Beach County, Florida, using a population-based random household survey. M. avium complex infection was identified by use of the M. avium sensitin skin test. Of 447 participants, 147 (32.9%) had a positive test reaction, 186 (41.6%) had a negative test reaction, and, for 114 (25.5%), test results were indeterminate. Among the 333 participants with positive or negative M. avium sensitin skin tests, age-adjusted independent predictors of M. avium complex infection in a multivariate model included Black race (odds ratio = 3.8, 95% confidence interval: 2.2, 6.6), birth outside the United States (odds ratio = 2.1, 95% confidence interval: 1.1, 3.9), and more than 6 years' cumulative occupational exposure to soil (odds ratio = 2.7, 95% confidence interval: 1.3, 6.0). Exposure to water, food, or pets was not associated with infection. Results indicate that soil is a reservoir for M. avium complex associated with human infection and that persons whose occupations involve prolonged soil exposure are at increased risk of M. avium complex infection.