Mycobacterium Mucogenicum Research Articles

Studies of antimicrobial resistance in rare mycobacteria from a nosocomial environment

BackgroundNontuberculous mycobacteria (NTM) are ubiquitous in nature and recognized agents of opportunistic infection, which is often aggravated by their intrinsic resistance to antimicrobials, poorly defined therapeutic strategies and by the lack of new drugs. However, evaluation of their prevalence in anthropogenic environments and the associated antimicrobial resistance profiles have been neglected. In this work, we sought to determine minimal inhibitory concentrations of 25 antimicrobials against 5 NTM isolates recovered from a tertiary-care hospital surfaces. Antimicrobial susceptibilities of 5 other Corynebacterineae isolated from the same hospital were also determined for their potential clinical relevance.ResultsOur phylogenetic study with each of the NTM isolates confirm they belong to Mycobacterium obuense, Mycobacterium mucogenicum and Mycobacterium paragordonae species, the latter initially misidentified as strains of M. gordonae, a species frequently isolated from patients with NTM disease in Portugal. In contrast to other strains, the M. obuense and M. mucogenicum examined here were resistant to several of the CLSI-recommended drugs, suggestive of multidrug-resistant profiles. Surprisingly, M. obuense was susceptible to vancomycin. Their genomes were sequenced allowing detection of gene erm (erythromycin resistance methylase) in M. obuense, explaining its resistance to clarithromycin. Remarkably, and unlike other strains of the genus, the Corynebacterium isolates were highly resistant to penicillin, ciprofloxacin and linezolid.ConclusionsThis study highlights the importance of implementing effective measures to screen, accurately identify and control viable NTM and closely related bacteria in hospital settings. Our report on the occurrence of rare NTM species with antibiotic susceptibility profiles that are distinct from those of the corresponding Type strains, along with unexpected resistance mechanisms detected seem to suggest that resistance may be more common than previously thought and also a potential threat to frail and otherwise vulnerable inpatients.

Inactivation of two Mycobacteria by free chlorine: Effectiveness, influencing factors, and mechanisms

Chlorination is one of the most widely used disinfection techniques, and the problem of “chlorine-resistant bacteria” (CRB) has attracted more attention recently. In this study, the deactivation of typical CRB in water, Mycobacterium fortuitum (M. fortuitum) and Mycobacterium mucogenicum (M. mucogenicum), by free chlorine was investigated with Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) as the reference. The chlorination effectiveness of chlorine on M. fortuitum and M. mucogenicum and the effect of chlorine concentration, pH, and humic acid were studied. It was found that M. mucogenicum was more resistant to chlorine than M. fortuitum, both of which were much more resistant than E. coli and B. subtilis. The effect of disinfectant concentration on the inactivation efficiency was positive, whereas the influence of pH and humic acid was negative. The inactivation mechanisms were explored by analyzing the bacteria morphology, the destruction of cell membrane, the cell hydrophobicity, as well as total adenosine triphosphate (ATP), superoxide dismutase (SOD) activity. The slight destruction of the cell membrane was observed after deactivation with chlorine, and high hydrophobicity of the cell membrane combined with metabolic changes might lead to the chlorine tolerance of Mycobacteria.

Isolation and characterization of nontuberculous mycobacteria from patients with pulmonary tuberculosis in Ghana.

Nontuberculous mycobacterial (NTM) species are assuming public health importance in pulmonary diseases; they are increasingly being isolated, and importantly, most NTMs do not respond to routine tuberculosis (TB) drugs. This study aimed to identify NTMs isolated from pulmonary TB cases and also determine their susceptibility to streptomycin (STR), isoniazid (INH), and rifampicin (RIF). A total of 1755 mycobacterial isolates, obtained between August 2012 and July 2014, from 2036 smear-positive pulmonary cases were identified using polymerase chain reaction amplification of IS6110, and hsp65 gene sequencing analysis. Drug susceptibility testing (DST) was then performed for the identified NTMs against STR, INH, and RIF using microplate Alamar blue assay. The results were analyzed against patients' biodata for statistical associations. Of the 1755 analyzed isolates, we identified 43 (2.5%) NTMs, which included 18 (41.9%) Mycobacterium intracellulare, 13 (30.2%) Mycobacterium avium subs. paratuberculosis, 5 (11.3%) Mycobacterium abscessus, 3 (7.0%) each of Mycobacterium mucogenicum and Mycobacterium colombiense, and 1 (2.3%) Mycobacterium simiae. Patients infected with NTMs (52.0%) were more likely to be human immunodeficiency virus-positive (P = 0.001, odds ratio = 6.6, 95% confidence interval = 2.7-16.2) than those infected with M. tuberculosis complex (5.8%). All the 43 (100%) NTMs were resistant to INH, whereas 32 (74%) and 19 (44%) were resistant to RIF and STR, respectively. Furthermore, 16 (37.2%) NTMs were resistant to all three drugs, 20 were resistant to INH and RIF, and 3 were resistant to STR and INH. All the M. abscessus isolates were resistant to all the three drugs, whereas all the M. avium isolates were resistant to INH and RIF, but only three were resistant to STR. Among the M. intracellulare isolates, 8, 18, and 15 isolates were resistant to STR, INH, and RIF, respectively. The observed high-resistance level to INH and RIF supports the need for rapid species identification and DST of nonresponding TB cases before retreatment.

Microbiological Quality and Occurrence of Nontuberculous Mycobacteria in Fresh-Squeezed Orange Juice Samples Purchased from Street Vendors in Mexico City

Nontuberculous mycobacteria (NTM) are potentially pathogenic agents commonly found in a natural ecosystem. For this reason, food is considered another source of NTM transmission for humans. The aims of this study were to evaluate the microbiological quality and the occurrence of NTM in fresh-squeezed orange juice samples purchased from street vendors. All 102 samples analyzed were positive for aerobic mesophilic bacteria (AMB), with limits ranging from 1.8 to 6.2 log CFU/ml. A total of 55 (54%), 25 (25%), and 13 (13%) orange juice samples were positive for total coliforms (TC), fecal coliforms (FC), and Escherichia coli , respectively. TC, FC, and E. coli were present with limits ranging from <3 to >1,100 most probable number (MPN)/ml, <3 to 460 MPN/ml, and <3 to 11 MPN/ml, respectively. Six orange juice samples harbored NTM. These NTM were identified by using three molecular markers (hsp65, rrs, and rpoB genes) and corresponded to the fast-growing mycobacteria: Mycobacterium fortuitum (n = 3), Mycobacterium rhodesiae (n = 1), Mycobacterium obuense (n = 1), and a mixture of M. fortuitum and Mycobacterium mucogenicum in an additional sample (n = 1). No correlation was found between the presence NTM in orange juice samples with the presence and concentration of the indicator microorganisms (aerobic mesophilic bacteria, TC, and FC). Overall, these results suggest that fresh-squeezed orange juice might represent a vehicle for NTM transmission in humans. Therefore, prevention of contamination by humans (proper handling and washing of oranges) during juice preparation should be recommended.

Toxic anterior segment syndrome caused by autoclave reservoir wall biofilms and their residual toxins

To identify etiology of toxic anterior segment syndrome (TASS) after uneventful phacoemulsification. EyeMD Laser and Surgery Center, Oakland, California. Retrospective case series. Patient charts with TASS were reviewed. Reservoirs of 2 autoclaves associated with these cases were cultured for bacterial contamination. Cultures were performed on 23 other autoclave reservoirs at surgery centers in the local area. The main outcome measures were the incidence of TASS and prevalence of bacterial biofilm contamination of autoclave reservoirs. From 2010 to 2013, 11 935 consecutive cataract surgeries were performed at 1 center by multiple surgeons with no reported TASS. Between January 1, 2014, and January 15, 2015, 10 cases of TASS occurred out of 3003 cataract surgeries; these patients' charts were reviewed. Cultures of 2 Statim autoclave reservoir walls grew Bacillus species, Williamsia species, Mycobacterium mucogenicum, and Candida parapsilosis. Scanning electron microscopy of reservoir wall sections showed prominent biofilm. The 2 autoclaves were replaced in January 2015. Subsequently, 2875 cataract surgeries were performed with no reported TASS (P<.001, χ2 test). Eighteen of 23 additional regional autoclaves were also contaminated with bacterial biofilms. Toxic anterior segment syndrome was strongly associated with bacterial biofilm contamination of autoclave reservoirs. An etiological mechanism might involve transport of heat-stable bacterial cell antigens in the steam with deposition on surgical instrumentation. Data suggest widespread prevalence of bacterial biofilms on fluid-reservoir walls, despite adherence to manufacturer guidelines for cleaning and maintenance. Prevention or elimination of autoclave fluid-reservoir biofilms might reduce the risk for postoperative TASS. None of the authors has a financial or proprietary interest in any material or method mentioned.

English

Mycobacterium ulcerans (MU), the causative agent of Buruli ulcer (BU), skin disease, is considered to be an environmental pathogen. The pathogenic virulence of MU is being linked to the expression of toxin called Mycolactone. Genetic analyses have shown the high diversity with variable number tandem repeats (VNTR) and mycobacterial interspersed repetitive units (MIRU) in M. ulcerans and in mycolactone producing Mycobacteria (MPMs). The purpose of this study is the molecular characterization of potentially pathogenic environmental mycobacteria strain, apart from the M. ulcerans, from aquatic environments in Cote d’Ivoire. A total of 473 samples were collected comprising of 251 water and 222 sediment based on sampling sites. The sediments were the most contaminated by mycobacteria with 60% as against 43.3% in water samples from the hyper endemic areas. In hypo-endemic areas, water was the most contaminated with 53.57% against 43.24% in sediment. Microscopy by Ziehl-Neelsen-staining, and PCR diagnostics using IS2404 and KR were performed on strains. 20% fast growing isolated mycobacteria species including Mycobacterium mucogenicum, Mycobacterium peregrinum and Mycobacterium sp. was found carrying the IS2404 gene previously found in M. ulcerans. 9.23% of strains carry the ketoreductase (KR) genes, one of the synthesis of mycolactone enzymes. In terms of genetic analysis using the MIRU/VNTR, the MIRU 1 was the most amplified sequence, and LOCUS 6 less amplified; no known profile have been identified in this study. This study is the first step taken in order to understand different skin infections encountered in Cote d’Ivoire. Key words: Mycobacterial interspersed repetitive units-variable number tandem repeats (MIRU-VNTR; ketoreductase, LOCUS 6, IS2404, Mycobacteria, Buruli ulcer.

Verification of Frequency in Species of Nontuberculous Mycobacteria in Kermanshah Drinking Water Supplies Using the PCR-Sequencing Method.

Nontuberculous mycobacteria are habitants of environment, especially in aquatic systems. Some of them cause problems in immunodeficient patients. Over the last decade, 16S rRNA gene sequencing was established in 45 novel species of nontuberculous mycobacteria. Experiences revealed that this method underestimates the diversity, but does not distinguish between some of mycobacterium subsp. To recognize emerging rapidly growing mycobacteria and identify their subsp, rpoB gene sequencing has been developed. To better understand the transmission of nontuberculous mycobacterial species from drinking water and preventing the spread of illness with these bacteria, the aim of this study was to detect the presence of bacteria by PCR-sequencing techniques. Drinking water samples were collected from different areas of Kermanshah city in west of IRAN. After decontamination with cetylpyridinium chloride, samples were filtered with 0.45-micron filters, the filter transferred directly on growth medium waiting to appear in colonies, then DNA extraction and PCR were performed, and products were sent to sequencing. We found 35/110 (32%) nontuberculous mycobacterial species in drinking water samples, isolates included Mycobacterium goodii, Mycobacterium aurum, and Mycobacterium gastri with the most abundance (11.5%), followed by Mycobacterium smegmatis, Mycobacterium porcinum, Mycobacterium peregrinum, Mycobacterium mucogenicum, and Mycobacterium chelonae (8%). In this study, we recognized the evidence of contamination by nontuberculous mycobacteria in corroded water pipes. As a result of the high prevalence of these bacteria in drinking water in Kermanshah, this is important evidence of transmission through drinking water. This finding can also help public health policy makers control these isolates in drinking water supplies in Kermanshah.

Mycobacterium mucogenicum Causing Central line-related sepsis in a home parenteral nutrition patient

Long-term home parenteral nutrition is associated with increased risk of line infection and subsequent sepsis. Line infections involving rapidly growing mycobacteria are almost exclusively found in immunocompromised patients. The authors report a case of opportunistic line-sepsis caused by Mycobacterium mucogenicum in a home parenteral nutritional patient with overt immunocompromise. Following a prolonged clinical course and molecular sequencing this infection was eventually diagnosed. The importance of awareness of rapidly growing mycobacteria as a causative agent of line infection in both immunocompromised and immunocompetent patients, the need for immediate removal of the line in such diagnosed infections, and the use of molecular techniques to identify atypical pathogens are emphasised. J Microbiol Infect Dis 2017; 7(2): 93-97 Parenteral, Nutrition, Central Line, Mycobacterium, Sepsis, Infection

Microbial pathogens in source and treated waters from drinking water treatment plants in the United States and implications for human health

An occurrence survey was conducted on selected pathogens in source and treated drinking water collected from 25 drinking water treatment plants (DWTPs) in the United States. Water samples were analyzed for the protozoa Giardia and Cryptosporidium (EPA Method 1623); the fungi Aspergillus fumigatus, Aspergillus niger and Aspergillus terreus (quantitative PCR [qPCR]); and the bacteria Legionella pneumophila (qPCR), Mycobacterium avium, M. avium subspecies paratuberculosis, and Mycobacterium intracellulare (qPCR and culture). Cryptosporidium and Giardia were detected in 25% and in 46% of the source water samples, respectively (treated waters were not tested). Aspergillus fumigatus was the most commonly detected fungus in source waters (48%) but none of the three fungi were detected in treated water. Legionella pneumophila was detected in 25% of the source water samples but in only 4% of treated water samples. M. avium and M. intracellulare were both detected in 25% of source water, while all three mycobacteria were detected in 36% of treated water samples. Five species of mycobacteria, Mycobacterium mucogenicum, Mycobacterium phocaicum, Mycobacterium triplex, Mycobacterium fortuitum, and Mycobacterium lentiflavum were cultured from treated water samples. Although these DWTPs represent a fraction of those in the U.S., the results suggest that many of these pathogens are widespread in source waters but that treatment is generally effective in reducing them to below detection limits. The one exception is the mycobacteria, which were commonly detected in treated water, even when not detected in source waters.

Mycobacterium Mucogenicum in Hematopoeitic Stem Cell Transplant Recipients and in High-Risk Patients Wit H Hematologic Malignancies, 2008-2013

Mycobacterium Mucogenicum in Hematopoeitic Stem Cell Transplant Recipients and in High-Risk Patients Wit H Hematologic Malignancies, 2008-2013

Epidemiology of Rapidly Growing Mycobacteria Bloodstream Infections

BackgroundRapidly growing mycobacteria (RGM) bloodstream infections (BSI) are an emerging problem often associated with therapeutic challenges. We review the epidemiology, treatment and outcomes over a 5-year period of a heterogeneous group presenting to our institution with RGM BSI. Materials and MethodsA retrospective cohort study of patients with primary RGM BSI from January 2006-December 2011 was conducted. Patient characteristics (age, race, sex and comorbidities), infection characteristics (catheter associated, hospital acquired, microbiology and antimicrobial susceptibilities), therapy and outcomes were recorded and compared by species. ResultsAmong 32 patients, 33 RGM BSI occurred. Patients had an average of 3-4 comorbidities, most commonly malignancy (45.5%). Most isolates (30.3%) were Mycobacterium fortuitum or Mycobacterium mucogenicum (27.2%), followed by Mycobacterium abscessus/chelonae (18.2%) and Mycobacterium immunogenum (12.2%). In all, 85% were catheter associated and 27.3% were hospital acquired. Empiric therapy was started in 19 (57.6%) patients and among these, it was adequate (at least 2 active agents based on susceptibilities) in 12 (63.2%). Among 21 patients with outcome data, cure was assumed for 14 (66.7%). One death was attributable to RGM BSI. Cure rates were higher among those who received adequate empiric therapy compared to those who did not (83.3% versus 42.9%). In general, antibiotic susceptibility was favorable across species for clarithromycin, amikacin and imipenem. ConclusionsRGM BSI occurred in a population with multiple comorbidities, most commonly malignancy, and most were catheter associated. Higher cures were seen among those who received adequate empiric therapy and based on susceptibility data, a broad empiric regimen of clarithromycin, amikacin and imipenem would be expected to be adequate.

Mycobacterium mucogenicum bacteremia in immune-compromised patients, 2008–2013

Mycobacterium mucogenicum (MM) is a rapidly growing nontuberculous mycobacterium that may rarely cause bacteremia in immune-compromised hosts. All MM cases from 2008 to 2013 were analyzed across 4 risk groups: stem cell transplantation (SCT), hematologic malignancy, solid tumors, and others. Descriptive analysis was performed, as well as comparative analysis of neutropenic patients (absolute neutrophil count ≤1000/μL) with nonneutropenic patients. Of 39 MM cases, 27 patients had undergone SCT. Neutropenia was present in 12 patients. There was a significant difference in the presence of fever at the time of MM bacteremia between neutropenic and nonneutropenic groups (92% versus 42%; P=0.005). Central venous catheter (CVC) was present in 33 cases. All patients were treated with >1 antibiotic. Most frequently used combination antibiotic regimen involved clarithromycin and amikacin. Median duration of antibiotic treatment was 42days. Bacteremia resolved in all cases with CVC removal and combination antibiotic treatment.

Mycobacterium mucogenicum in Stem Cell Transplant Recipients and in High-Risk Patients With Hematological Malignancies, 2008-2013.

Mycobacterium mucogenicum in Stem Cell Transplant Recipients and in High-Risk Patients With Hematological Malignancies, 2008-2013.

Utility of the MALDI-TOF MS method to identify nontuberculous mycobacteria.

In comparison to the conventional real-time polymerase chain reaction method (PCR method) or the DNA-DNA hybridization method (DDH method), the utility of NTM identification by the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method has seldom been reported. In this study, 75 clinical NTM isolates from our hospital between April 2013 and July 2014 were identified and analyzed using PCR, DDH, and MALDI-TOF MS methods, and the results for the MALDI-TOF MS method were compared with the others. Identification at the species level was in agreement for 71 (94.5%) of the 75 isolates. For further details, identification was possible for 23 (95.8%) of 24 Mycobacterium avium, 11 (100%) of 11 Mycobacterium intracellulare, and 1 (50%) of 2 isolates mixed with M.avium and M. intracellulare. Mycobacterium ksansasii, Mycobacterium abscessus, Mycobacterium fortuitum, Mycobacterium gordonae, and Mycobacterium chelonae identified by DDH method were same result by MALDI-TOF MS. Additionally, Mycobacterium mucogenicum, which could not be identified by the DDH method, was identified by the MALDI-TOF MS method. However, two isolates identified as Mycobacterium terrae by DDH method could not be identified by the MALDI-TOF MS method and were determined to be Mycobacterium arupense by 16S ribosomal RNA (rRNA) sequence analysis. The present findings show that, for rare bacterial species, identification is sometimes not possible, but, in most cases, the results of identification by the MALDI-TOF MS method have a high concordance rate with the results of the PCR and DDH methods.

Mycobacterium mucogenicum Central Venous Line Infection: Successful Treatment in a 2-Year-Old Child without Line Removal

We report the first case of successful treatment of Mycobacterium mucogenicum central venous line (CVL) infection which did not require removal and replacement of the line. A 2-year-old boy with type 3 intestinal failure on long-term home parenteral nutrition via CVL, presented to the emergency department with fever and tachycardia. CVL infection was suspected and amikacin and piperacillin/tazobactam were started immediately in line with local protocol. Consecutive blood cultures grew M. mucogenicum, a rapidly growing nontuberculous mycobacterium species. Following consultation with microbiology, the agreed course of action was to treat the infection with antibiotics while leaving the CVL in place. Clarithromycin and ciprofloxacin were added, and subsequent blood culture on day 6 of treatment showed no bacterial growth. He completed 14 days of antibiotics and has remained well with no further line infection to date (6 months postpresentation). Knowledge that this infection may be successfully treated with the appropriate antibiotics could give clinicians confidence to leave a CVL in place if the patient is clinically stable and immunocompetent. This is of significant importance when preserving vascular access is crucial.

Increased Frequency of Nontuberculous Mycobacteria Detection at Potable Water Taps within the United States.

Nontuberculous mycobacteria (NTMs) are environmental microorganisms that can cause infections in humans, primarily in the lung and soft tissue. The prevalence of NTM-associated diseases is increasing in the United States. Exposure to NTMs occurs primarily through human interactions with water (especially aerosolized). Potable water from sites across the U.S. was collected to investigate the presence of NTM. Water from 68 taps was sampled 4 times over the course of 2 years. In total, 272 water samples were examined for NTM using a membrane filtration, culture method. Identification of NTM isolates was accomplished by polymerase chain reaction (PCR) amplification of the 16S rRNA and hsp65 genes. NTMs were detected in 78% of the water samples. The NTM species detected most frequently were: Mycobacterium mucogenicum (52%), Mycobacterium avium (30%), and Mycobacterium gordonae (25%). Of the taps that were repeatedly positive for NTMs, the species M. avium, M. mucogenicum, and Mycobacterium abscessus were found to persist most frequently. This study also observed statistically significant higher levels of NTM in chloraminated water than in chlorinated water.

Absence of a functional erm gene in isolates of Mycobacterium immunogenum and the Mycobacterium mucogenicum group, based on in vitro clarithromycin susceptibility.

Macrolide resistance has been linked to the presence of a functional erythromycin ribosomal methylase (erm) gene in most species of pathogenic rapidly growing mycobacteria (RGM). For these Mycobacterium isolates, extended incubation in clarithromycin is necessary to determine macrolide susceptibility. In contrast, the absence of a detectable erm gene in isolates of M. chelonae, M. senegalense, and M. peregrinum and a nonfunctional erm gene in M. abscessus subsp. massiliense and 15% to 20% of M. abscessus subsp. abscessus isolates renders these species intrinsically macrolide susceptible. Not all RGM species have been screened for the presence of an erm gene, including the Mycobacterium mucogenicum group (M. mucogenicum, M. phocaicum, and M. aubagnense) and Mycobacterium immunogenum. A total of 356 isolates of these two pathogenic RGM taxa from two reference laboratories (A.R.U.P. Reference Laboratories and the Mycobacteria/Nocardia Laboratory at the University of Texas Health Science Center at Tyler) underwent clarithromycin susceptibility testing with readings at 3 to 5 days and 14 days. Only 13 of the 356 isolates had resistant clarithromycin MICs at initial extended MIC readings, and repeat values on all available isolates were ≤2 μg/ml. These studies suggest that these two additional RGM groups do not harbor functional erm genes and, like M. chelonae, do not require extended clarithromycin susceptibility testing. We propose to the Clinical Laboratory and Standards Institute that isolates belonging to these above-mentioned six rapidly growing mycobacterial groups based on molecular identification with no known functional erm genes undergo only 3 to 5 days of susceptibility testing (to exclude mutational resistance).

Rapidly Growing Mycobacterium Infections in Cancer Patients

Background Rapidly growing mycobacterium (RGM) is a group of ubiquitous organisms mostly found in soil and water. In the immunocompromised population, they are considered to be opportunistic and cause systemic illness, which leads to higher mortality. Methods Our study entailed a retrospective chart review conducted at the Moffitt Cancer Center. The computerized epidemiology report provided by the microbiology laboratory identified patients who had been diagnosed with an RGM infection from January 1990 to October 2008. Results Of the 45 patients included, 24 were women and 21 were men. The median age of these patients was 58 years. Twenty-one (46.7%) of the 45 patients had a hematologic malignancy consisting of multiple myeloma, acute and chronic leukemia, myelodysplastic syndrome, and lymphoma. We collected data from 10 patients (22.2%) who had breast cancer and five (11.1%) with lung cancer. Eight of the patients (17.8%) had other forms of malignancy consisting of ovarian, thyroid, skin, sinuses, scalp, and gastrointestinal malignancies. Of the 45 cases analyzed, 4 species of RGM were identified including 26 cases (57.8%) of Mycobacterium abscessus, 13 (28.9%) with Mycobacterium fortuitum, two (4.4%) with Mycobacterium chelonae, and two (4.4%) with Mycobacterium mucogenicum. Two patients (4.4%) were diagnosed with Mycobacterium abscessus/chelonae complex. Conclusions Our study demonstrates the diversity of malignancies associated with RGM infections. We add 45 more documented cases to the current collection of data correlating malignancies and RGM infections. Future research regarding treatment options for RGM infections is much needed due to high levels of resistance and limited treatment options.

Non-tuberculous mycobacteria, amoebae and bacterial indicators in swimming pool and spa

Non-tuberculous mycobacteria are microorganisms commonly living in the environment. Nevertheless, most of them are opportunistic pathogens. To verify their concentrations in swimming pool and spa, analyses were performed on water and biofilm samples and the data were correlated to the global microbiological quality of water.The 93% of samples were found positive for the investigated bacteria. All water samples were positive for mycobacteria with higher densities in the whirlpool (105cfu/L). Swimming pool samples showed variable counts ranging from 29 to 7×104cfu/L while similar levels of mycobacteria (around to 102cfu/L) characterized water samples from the spa.The 80% of the biofilm samples were positive and one of them was characterized by very high densities (3.7×103cfu/cm2).The most frequently isolated species was Mycobacterium mucogenicum followed by Mycobacterium immunogenum.Free-living amoebae were never detected in swimming pools and in the whirlpool, while they were found in 75% of spa samples and in 67% of biofilm samples.The mean values of heterotrophic bacteria in swimming pool water were similar to those observed in spa water at both temperatures. Higher values were detected in the whirlpool. Microbial indicators of fecal contamination, Staphylococcus aureus and Pseudomonas aeruginosa were never detected both in water and in biofilm samples.No correlation exists between the monitoring controls carried out by law and the occurrence of mycobacteria that may represent a potential risk in facilities such as those investigated.

A case of Mycobacterium mucogenicum infection in a liver transplant recipient and a review of the literature

Bacterial, viral, and fungal infections can be devastating in a postoperative liver transplant recipient on multidrug immunosuppressive therapy. Various atypical (nontuberculous mycobacteria [NTM]) mycobacterial infections have been reported in the solid organ transplant population, but to our knowledge, no cases of Mycobacterium mucogenicum infections have been reported. Here, we report a case of a patient with end-stage liver disease secondary to primary biliary cirrhosis, model for end-stage liver disease score of 29, who underwent deceased-donor orthotopic liver transplantation, with her postoperative course complicated by multiple pleural effusions and peritonitis. Despite numerous courses of antibiotics, her condition did not improve. Acid-fast bacilli cultures grew M.mucogenicum, which was then treated with appropriate antimicrobical therapy. M.mucogenicum, a rapidly growing NTM that can be present in water contamination, should be recognized as a potential source of infection, especially in the immunocompromised population.