Mycobacterium Mucogenicum Research Articles

Investigation of Healthcare-Associated Infection Risks from Ice: Summary of CDC Consultations 2016-2023

Background: Nonsterile ice is frequently used in healthcare settings for a wide array of patient care activities and clinical procedures. However, this ice can harbor pathogenic organisms which can threaten patient safety and cause outbreaks. We sought to characterize recent Centers for Disease Control and Prevention (CDC) consultations involving ice leading to healthcare-associated infections (HAIs). Methods: We reviewed internal CDC records from the Division of Healthcare Quality Promotion (DHQP) to identify investigations of outbreaks and potential outbreaks involving the use of ice in healthcare facilities. We searched records from January 1, 2016, through November 30, 2023, for keywords related to ice. We excluded consultations in which ice was not thought to be a potential transmission pathway as well as those in which only sterile ice products (e.g., saline slush) were investigated. Results: We identified 45 consultations for ice-related investigations, involving a total of 533 patients. Nontuberculous mycobacteria were the most frequently implicated organisms, appearing in 40% (n=18) of investigations. Eighty-four percent (n=38) of investigations occurred in acute care hospitals. The most frequently implicated hospital settings were intensive care units (13%, n=6), operating rooms (13%, n=6), and bronchoscopy suites (13%, n=6). We identified a variety of plausible exposure pathways, including direct ingestion of ice by patients, use of ice during the bronchoscopy procedure, use of nonsterile ice in heater-cooler devices during cardiothoracic surgery, and the use of ice to chill saline for respiratory care. Environmental sampling directly of ice machines was performed in 62% of investigations (n=28) and nonsterile ice from these machines was sampled in 9% of investigations (n=4). Among those investigations in which ice machines were sampled, the organism implicated in the outbreak was isolated in 54% of investigations (n=15). Among those investigations in which ice itself was sampled, the organism implicated in the outbreak was isolated in 75% of investigations (n=3). These organisms included Mycobacterium mucogenicum, Burkholderia multivorans, and Acanthamoeba spp. Conclusions: The use of nonsterile ice during clinical care is a potential source of pathogens that cause patient infections and HAI outbreaks. Healthcare personnel should be aware of the risk posed by nonsterile ice and consider avoiding its use, especially when caring for patients who are critically ill or immunocompromised. Healthcare facilities should ensure regular cleaning and disinfection of ice machines to decrease their microbial burden. When HAI outbreaks involving water-associated organisms are identified, nonsterile ice should be considered as a potential mode of transmission.

Beyond the Needle: Unmasking Atypical Mycobacteria in Postvaccination Abscesses in Children.

Atypical or nontuberculous mycobacteria (NTM) are an environmental organism responsible for opportunistic infection. Rapid-growing NTM are more commonly associated with hospital-acquired infections. Many of the organisms responsible for diseases in immunocompromised patients and hospital-acquired infections originate from tap water, such as Mycobacterium kansasii, Mycobacterium xenopi, Mycobacterium gordonae, Mycobacterium simiae, Mycobacterium mucogenicum, Mycobacterium fortuitum, Mycobacterium chelonae, and Mycobacterium abscessus. NTM is a rare organism responsible for the injection abscess. Considering low incidents, not much clinical data are available for this condition. Here, we discuss such cases which can be helpful to spread awareness and provide data for future policy makers. This was a retrospective study. Data on patients with injection abscess were collected from the last 6 years. Detailed history and clinical examination findings were analyzed. Children with injection abscess were operated and their further management and outcome were studied. A total of 13 cases with confirmed culture of NTM were treated over 6 years. The age ranged from 2½ months to 5¾ years with male:female ratio of 7:6. All patients hailed from the same geographical area. All children were healthy with no history of any long-term or chronic illness, without additional symptoms and had received Bacillus Calmette-Guérin vaccination at birth. The total duration of illness varied from 1 to 5 months, with a mean of 3 months. All patients had a history of intramuscular age-appropriate vaccination as per the national immunization schedule. All patients were followed up to 6 months after intervention and none of our patients developed relapse. Patient who does not respond with optimum treatment should have a high suspicion of such opportunistic infection, which is crucial to their management. Hospital-acquired NTM infections often result from contaminated instruments or fluids. Adherence to strict aseptic precautions, hand hygiene and environmental precautions are the key to preventing these infections. In case of skin and soft tissue infections / abscesses, surgical intervention plays a significant role for managing the patient.

Occurrence and diversity of nontuberculous mycobacteria affected by water stagnation in building plumbing

Abstract Nontuberculous mycobacteria (NTM) refer to mycobacteria other than Mycobacterium tuberculosis and Mycobacterium leprae. Some NTM are known to cause pulmonary and skin diseases. As NTM are prevalent in water supply systems, the health burden of waterborne NTM is concerned. However, little is known about NTM in building plumbing. This study revealed the abundance and diversity of NTM in building plumbing by using culture-dependent and culture-independent approaches. Moreover, the chlorine susceptibility of NTM isolates in tap water was evaluated. The increase in the abundance of Mycobacterium spp. was observed in some taps after 24 h of stagnation, indicating that NTM could have the potential to regrow in building plumbing. While Mycobacterium mucogenicum and Mycobacterium avium were detected by cultivation, amplicon sequencing of NTM-specific hsp65 genes revealed that Mycobacterium gordonae was dominant in most of the samples, which was not detected by cultivation. The chlorine susceptibility experiment demonstrated that NTM strains related to M. avium and M. mucogenicum were 119 and 426 times more tolerant to chlorine than Escherichia coli, respectively. As M. mucogenicum, M. avium, and M. gordonae are regarded as opportunistic pathogens, intensive monitoring of NTM in tap water in building plumbing is necessary.

Deciphering the diversity and assemblage mechanisms of nontuberculous mycobacteria community in four drinking water distribution systems with different disinfectants

Nontuberculous mycobacteria (NTM) represent an emerging health concern due to their escalating infections worldwide. Although drinking water distribution systems (DWDSs) have been considered as NTM reservoirs and a potential infection route, NTM community at the species level remain largely elusive in DWDSs. This study employed high-throughput sequencing coupled with qPCR to profile NTM community and estimate their abundances at the species level in water and biofilm samples in four DWDSs using three different disinfectants (i.e. free chlorine, chloramine and chlorine dioxide). Results demonstrated the dominance of Mycobacterium paragordonae and Mycobacterium mucogenicum in both biofilm and water across four DWDSs, whereas Mycobacterium abscessus and Mycobacterium chelonae, the two clinically significant species, exhibited low abundance but high prevalence. Comparable NTM community was observed in biofilm across these four DWDSs. Distinct separation of NTM community between SH-chloramine DWDSs water and other DWDSs highlighted the selective pressure of chloramine on NTM community. Furthermore, the research revealed that biofilm and water exhibited distinct NTM community structures, with biofilm harboring more diverse NTM community. Certain NTM species displayed a preference for biofilm, such as Mycobacterium gordonae, while others, like Mycobacterium mucogenicum, were more abundant in water samples (P < 0.05). In terms of NTM community assembly, stochastic processes dominated biofilm, while comparable role of stochastic and deterministic processes was observed in water. In conclusion, this study offers a pioneering and comprehensive insight into the dynamics and assembly mechanisms of NTM community within four DWDSs treated with three distinct disinfectants. These findings serve as a critical foundation for assessing NTM exposure risks and devising effective management strategies within DWDSs.

A bronchoscopy-associated pseudo-outbreak of Mycobacterium chelonae and Mycobacterium mucogenicum associated with contaminated ice machine water and ice.

A pseudo-outbreak of bronchoscopy-associated Mycobacterium chelonae and M. mucogenicum was traced to contaminated ice machine water and ice. A nonsterile ice bath was used to cool uncapped, sterile, saline syringes used to slow procedural bleeding. Joining the growing evidence of bronchoscopy pseudo-outbreaks, our investigation describes several lessons for future prevention.

Shower water contributes viable nontuberculous mycobacteria to indoor air.

Nontuberculous mycobacteria (NTM) are frequently present in municipal drinking water and building plumbing, and some are believed to cause respiratory tract infections through inhalation of NTM-containing aerosols generated during showering. However, the present understanding of NTM transfer from water to air is insufficient to develop NTM risk mitigation strategies. This study aimed to characterize the contribution of shower water to the abundance of viable NTM in indoor air. Shower water and indoor air samples were collected, and 16S rRNA and rpoB genes were sequenced. The sequencing results showed that running the shower impacted the bacterial community structure and NTM species composition in indoor air by transferring certain bacteria from water to air. A mass balance model combined with NTM quantification results revealed that on average 1/132 and 1/254 of NTM cells in water were transferred to air during 1 hour of showering using a rain and massage showerhead, respectively. A large fraction of the bacteria transferred from water to air were membrane-damaged, i.e. they had compromised membranes based on analysis by live/dead staining and flow cytometry. However, the damaged NTM in air were recoverable as shown by growth in a culture medium mimicking the respiratory secretions of people with cystic fibrosis, implying a potential infection risk by NTM introduced to indoor air during shower running. Among the recovered NTM, Mycobacterium mucogenicum was the dominant species as determined by rpoB gene sequencing. Overall, this study lays the groundwork for future pathogen risk management and public health protection in the built environment.

Comparison of Macrophage Immune Responses and Metabolic Reprogramming in Smooth and Rough Variant Infections of Mycobacterium mucogenicum.

Mycobacterium mucogenicum (Mmuc), a rapidly growing nontuberculous mycobacterium (NTM), can infect humans (posttraumatic wound infections and catheter-related sepsis). Similar to other NTM species, Mmuc exhibits colony morphologies of rough (Mmuc-R) and smooth (Mmuc-S) types. Although there are several case reports on Mmuc infection, no experimental evidence supports that the R-type is more virulent. In addition, the immune response and metabolic reprogramming of Mmuc have not been studied on the basis of morphological characteristics. Thus, a standard ATCC Mmuc strain and two clinical strains were analyzed, and macrophages were generated from mouse bone marrow. Cytokines and cell death were measured by ELISA and FACS, respectively. Mitochondrial respiration and glycolytic changes were measured by XF seahorse. Higher numbers of intracellular bacteria were found in Mmuc-R-infected macrophages than in Mmuc-S-infected macrophages. Additionally, Mmuc-R induced higher levels of the cytokines TNF-α, IL-6, IL-12p40, and IL-10 and induced more BMDM necrotic death. Furthermore, our metabolic data showed marked glycolytic and respiratory differences between the control and each type of Mmuc infection, and changes in these parameters significantly promoted glucose metabolism, extracellular acidification, and oxygen consumption in BMDMs. In conclusion, at least in the strains we tested, Mmuc-R is more virulent, induces a stronger immune response, and shifts bioenergetic metabolism more extensively than the S-type. This study is the first to report differential immune responses and metabolic reprogramming after Mmuc infection and might provide a fundamental basis for additional studies on Mmuc pathogenesis.

Outcomes of Nontuberculous Mycobacterial Keratitis After Clear Corneal Incision Phacoemulsification Surgery: A Case Series of 6 Eyes in South Florida.

The purpose of this study was to present the successful management and outcomes in a series of 6 cases of culture-positive nontuberculous mycobacterial keratitis after clear corneal incision phacoemulsification surgery. This is a case series of 6 consecutive eyes that presented at the Cornea Division at an academic institution, diagnosed with culture-positive nontuberculous mycobacterial keratitis after phacoemulsification surgery. Six eyes of 5 patients were included. The mean interval from cataract surgery to presentation was 7.7 weeks. All cases presented with intrastromal abscesses adjacent to corneal incisions, and 2 had scleral extension of the infection. Isolated organisms were Mycobacterium abscessus (n = 4), Mycobacterium chelonae (n = 1), and Mycobacterium mucogenicum (n = 1). All cases were treated with topical amikacin 8 mg/mL for 10.5 weeks on average. All cases received either oral clarithromycin at 500 mg twice-daily dosage or oral azithromycin at 500 mg daily. Two patients with scleral abscesses underwent surgical debridement with amniotic membrane grafts. All 6 eyes achieved infection resolution and good visual recovery, with the final visual acuity ranging from 20/20 to 20/60. None of the patients experienced recurrence of infection. Prompt medical treatment with combined topical and oral therapy can lead to infection resolution and favorable visual recovery. Early surgical intervention can ensure good outcomes in cases of scleral extension.

Identification of Nontuberculous Mycobacteria in Drinking Water in Cali, Colombia

Nontuberculous mycobacteria (NTM) are ubiquitous microorganisms naturally resistant to antibiotics and disinfectants that can colonize drinking water supply systems. Information regarding the spread of NTM in specifically South America and Colombia is limited. We aimed to identify and characterize NTM present in tap water samples from Cali, Colombia. Drinking water samples and faucet biofilm swabs were collected in 18 places, including the city’s three main water treatment plants (WTPs). Filter-trapped material and eluates (0.45 μm) from swab washes were plated in 7H11 agar plates. Suspected colonies were evaluated microscopically, and NTM species were identified based on the rpoB gene. Antibiotic susceptibility testing was also performed. Fifty percent (9/18) of sampling points were positive for NTM (including two WTPs), from which 16 different isolates were identified: Mycobacterium mucogenicum (8/16), M. phocaicum (3/16), M. chelonae (2/16), M. mageritense (2/16), and M. fortuitum (1/16), all rapidly growing mycobacteria. A susceptibility profile was obtained from 68.75% (11/16) of the isolates. M. chelonae was the most resistant species. All NTM isolated are potentially responsible for human diseases; our findings might provide a baseline for exploring NTM transmission dynamics and clinical characterization, as well as potential associations between NTM species found in drinking water and isolates from patients.

Mycobacterium mucogenicum and Klebsiella pneumoniae Pulmonary Infection in a Patient Following Cardiac Surgery: A Case Report

Introduction: Mycobacterium mucogenicum belongs to the rapidly growing mycobacteria, and it is a rare conditional pathogen. Although recent studies suggested that the incidence of M. mucogenicum infection was increased worldwide, there are no case reports of M. mucogenicum and Klebsiella pneumoniae pulmonary infection. Case Presentation: A 32-year-old non-smoking male was diagnosed with congenital atrial septal defect and pulmonary arterial hypertension. After cardiac surgery, lung infections were observed in the patient and then rapidly developed acute respiratory distress syndrome. The cefoperazone-sulbactam, vancomycin, ceftazidime, carbapenem, tigecycline, and micafungin were used for the treatment of pulmonary infection but did not work well. Ultimately, M. mucogenicum and K. pneumoniae were identified as pathogens by using next-generation sequencing. The patient was treated successfully with the administration of clarithromycin, linezolid, tigecycline, and ceftazidime-avibactam. The clinical outcome of this patient was favorable without relapse of infection. Conclusions: This case demonstrates that M. mucogenicum pulmonary infection may result in severe outcomes. The next-generation sequencing technology is important for the identification of M. mucogenicum. Additionally, the clinicians and clinical pharmacists should remain awareness in dealing with M. mucogenicum infection to avoid delaying appropriate treatment.

Mycobacterium mucogenicum and Mycobacterium neoaurum bacteremia in immunocompromised hosts.

Mycobacterium mucogenicum and Mycobacterium neoaurum are infrequent causes of bacteremia in humans. When they are isolated from blood, it is not unusual for them to initially be considered contaminants. A retrospective chart review of patients diagnosed with M. mucogenicum and M. neoaurum bacteremia from January 1998 to December 2018 was conducted at the University Health Network, Toronto, Ontario, Canada. We identified 28 patients who had bacteremia caused by these organisms. These patients were primarily immunocompromised, had chronically indwelling vascular access devices, or used intravenous drugs. For 29% of the patients, the isolation of these mycobacteria was considered colonization, whereas 82% of the patients received antimicrobial therapy and 95% had the central line removed. The removal of the vascular access device and treatment with either single or combination antimicrobial therapy produced successful outcomes for people with these infections.

Mycobacterium Mucogenicum Bacteremia and Nodular Soft Tissue Infection in a Person Who Uses Tap Water to Inject Drugs.

The ongoing North American epidemic of intravenous opioid and methamphetamine use increases the occurrence of bacteremia from environmental organisms. In this study, we report a case of Mycobacterium mucogenicum bacteremia and associated nodular soft tissue infection in a person who uses tap water to inject drugs.

Analysis of microbial contamination of household water purifiers.

Household water purifiers are increasingly used to treat drinking water at the household level, but their influence on the microbiological safety of drinking water has rarely been assessed. In this study, representative purifiers, based on different filtering processes, were analyzed for their impact on effluent water quality. The results showed that purifiers reduced chemical qualities such as turbidity and free chlorine. However, a high level of bacteria (102-106CFU/g) was detected at each stage of filtration using a traditional culture-dependent method, whereas quantitative PCR with propidium monoazide (PMA) treatment showed 106-108 copies/L of total viable bacteria in effluent water, indicating elevated microbial contaminants after purifiers. In addition, high-throughput sequencing revealed a diverse microbial community in effluents and membranes. Proteobacteria (22.06-97.42%) was the dominant phylum found in all samples, except for purifier B, in which Melainabacteria was most abundant (65.79%). For waterborne pathogens, Escherichia coli (100-106 copies/g) and Pseudomonas aeruginosa (100-105 copies/g) were frequently detected by qPCR. Sequencing also demonstrated the presence of E. coli (0-6.26%), Mycobacterium mucogenicum (0.01-3.46%), and P. aeruginosa (0-0.16%) in purifiers. These finding suggest that water from commonly used household purifiers still impose microbial risks to human health.

Hospital ice, ice machines, and water as sources of nontuberculous mycobacteria: Description of qualitative risk assessment models to determine host-Nontuberculous mycobacteria interplay.

Over the last 30 years, there have been at least 17 published reports of nontuberculous mycobacteria (NTMs) being isolated from hospital ice or ice-making machines. Of these, 12 were reports of pseudo-outbreaks, i.e., the nosocomial transmission of organism from hospital ice/ice machines to patients, resulting in patient colonization, but with no disease manifestations. In addition, there were five outbreaks that resulted in clinical disease/pathology associated with NTM organism. Eleven different species of NTMs have been associated with these reports, where over half (59%) of the species identified were Mycobacterium fortuitum (18%), Mycobacterium gordonae (14%), Mycobacterium mucogenicum (14%), and Mycobacterium porcinum (14%). Several of these reports clearly documented that ice machines had been properly maintained, cleaned, and serviced in accordance with the CDC guidelines yet became contaminated with NTM organisms. These reports frequently detail that after extensive cleaning/disinfection following the discovery of NTM organisms, ice machines remained contaminated with NTM organisms, highlighting the difficulty in eradicating these from ice machines, once contaminated. Several reports identified that the only remedy to the contamination problem was to replace the ice machine with a new machine. Two qualitative risk assessment models are presented for (i) patients exposed to contaminated ice machine but before NTM colonization/infection and (ii) patients already colonized with NTMs from ice machines. Therefore, to protect immunocompromised/immunosuppressed patients' safety, especially during surgical or respiratory procedures, ice should not be sourced from the ice machine but should be made from sterile water and stored safely and separately away from the ice machine.

An overview of pulmonary infections due to rapidly growing mycobacteria in South Asia and impressions from a subtropical region.

Rapidly growing mycobacteria (RGM) comprise nearly half of the validated species of nontuberculous mycobacteria (NTM) and have been reported to have a higher incidence in Asia as compared to Europe and America. There is limited information on RGM infections from South Asia. Hence, the present study aimed to ascertain the incidence of pulmonary infections due to RGM in Delhi and to review the status of available information on the prevalence of RGM in South Asia, a region endemic for tuberculosis. We analyzed 933 mycobacterial isolates obtained from pulmonary samples in Delhi and performed species identification by polymerase chain reaction (PCR)-restriction analysis (restriction fragment length polymorphism) and line probe assay. Drug susceptibility testing (DST) was performed by broth microdilution method. We also reviewed reports available on pulmonary infections in South Asia, attributed to RGM. Of the 933 mycobacterial isolates studied, NTM were identified in 152 (16.3%). Of these, 65/152 (42.8%) were RGM comprising Mycobacterium fortuitum (34/65; 52.3%), Mycobacterium abscessus (25/65; 38.5%), Mycobacterium chelonae (3/65; 4.61%), Mycobacterium mucogenicum (2/65; 3.1%), and Mycobacterium smegmatis (1/65; 1.5%). On applying the American Thoracic Society/Infectious Diseases Society of America guidelines, 11/25 (44%) M. abscessus, 3/3 (100%) M. chelonae, and both isolates of M. mucogenicum were found to be clinically relevant. DST revealed that maximum susceptibility of the RGM was seen to linezolid, clarithromycin, and amikacin. Of the RGM isolated in the present study, 16/65 (24.6%) were found to be clinically relevant. Hence, it is important to recognize these organisms as potential pathogens to identify patients with RGM disease to initiate appropriate therapy.

A bronchoscopy-associated pseudo-outbreak of Mycobacterium mucogenicum traced to use of contaminated ice used for bronchoalveolar lavage

A bronchoscopy-associated pseudo-outbreak of Mycobacterium mucogenicum traced to use of contaminated ice used for bronchoalveolar lavage

Insight into the biology of Mycobacterium mucogenicum and Mycobacterium neoaurum clade members

Nontuberculous mycobacteria, NTM, are of growing concern and among these members of the Mycobacterium mucogenicum (Mmuc) and Mycobacterium neoaurum (Mneo) clades can cause infections in humans and they are resistant to first-line anti-tuberculosis drugs. They can be isolated from different ecological niches such as soil, tap water and ground water. Mycobacteria, such as Mmuc and Mneo, are classified as rapid growing mycobacteria, RGM, while the most familiar, Mycobacterium tuberculosis, belongs to the slow growing mycobacteria, SGM. Modern “omics” approaches have provided new insights into our understanding of the biology and evolution of this group of bacteria. Here we present comparative genomics data for seventeen NTM of which sixteen belong to the Mmuc- and Mneo-clades. Focusing on virulence genes, including genes encoding sigma/anti-sigma factors, serine threonine protein kinases (STPK), type VII (ESX genes) secretion systems and mammalian cell entry (Mce) factors we provide insight into their presence as well as phylogenetic relationship in the case of the sigma/anti-sigma factors and STPKs. Our data further suggest that these NTM lack ESX-5 and Mce2 genes, which are known to affect virulence. In this context, Mmuc- and Mneo-clade members lack several of the genes in the glycopeptidolipid (GLP) locus, which have roles in colony morphotype appearance and virulence. For the M. mucogenicum type strain, MmucT, we provide RNASeq data focusing on mRNA levels for sigma factors, STPK, ESX proteins and Mce proteins. These data are discussed and compared to in particular the SGM and fish pathogen Mycobacterium marinum. Finally, we provide insight into as to why members of the Mmuc- and Mneo-clades show resistance to rifampin and isoniazid, and why MmucT forms a rough colony morphotype.

A bronchoscopy-associated pseudo-outbreak of Mycobacterium mucogenicum traced to use of contaminated ice used for bronchoalveolar lavage.

Clonal Mycobacterium mucogenicum isolates (determined by molecular typing) were recovered from 19 bronchoscopic specimens from 15 patients. None of these patients had evidence of mycobacterial infection. Laboratory culture materials and bronchoscopes were negative for Mycobacteria. This pseudo-outbreak was caused by contaminated ice used to provide bronchoscopic lavage. Control was achieved by transitioning to sterile ice.

A Retrospective Chart Review to Assess Indications, Risk Factors and Complications Associated with the Use of Indwelling Catheters in Pediatric Patients with Sickle Cell Disease - a Single Institution Experience

Background: Sickle cell disease (SCD) and its complications are associated with frequent hospital visits and treatment often requires venous access for administration of fluids, medications and blood transfusions. Due to frequent use, peripheral venous access can become difficult over time because of venous scarring. Moreover, certain interventions such as chronic simple or exchange transfusions require reliable venous access for prolonged periods of time. Implantable central venous devices such as ports offer definitive access and mitigate the need for frequent peripheral access attempts. However, existing knowledge on the use of these devices in pediatric patients with SCD is limited. Due to possible increased risks of thrombosis and mechanical occlusion from hypercoagulable state, risk of infectious complications and need for surgical placement, ports are often not used routinely. We review the indications and complications associated with placement of ports in the pediatric cohort of patients with SCD - to better define the scope of port placement in this group. Methods: We performed an IRB-approved, retrospective chart review to assess the indications, complications and risk factors associated with port placement in children and adolescents with SCD at the University of Oklahoma Health Sciences Center (OUHSC). The study period analyzed was 17.5 years from January 1st, 2000 to July 30th, 2018 and included patients from birth to 21 years of age, diagnosed with SCD who had homozygous sickle cell disease (HbSS) or compound heterozygous SCD - either sickle cell-β0-thalassemia, sickle cell-β+-thalassemia or sickle cell-hemoglobin C (HbSC) disease, and had ports in place for more than 7 days. Patients were identified systematically by querying the OUHSC Clinical Data Warehouse using diagnostic codes followed by chart review. Results: Thirty-two patients with SCD and ports were identified during the study period, out of which 31 patients had HbSS and one patient had HbSC disease. The median age at first port insertion was 8 years (range 1-20 years). A total of 63 ports were placed for a total of 99,272 port days with a median port life span of 1340 days. The two main indications for port placement were - either chronic transfusions for which 48 ports were placed for a total of 80,238 port days, or poor venous access (PVA) for which 15 ports were placed for a total of 19,034 port days. Out of the 48 ports placed for chronic transfusions, 6 ports were for transfusions for primary stroke prophylaxis, 22 ports were for transfusions for secondary stroke prophylaxis, 17 ports were for transfusions for recurrent vaso-occlusive episodes (VOE) and 3 ports were for transfusions after multi-organ failure. A total of 54 port complications occurred (malfunction=29, infection=20, thrombosis=3, difficult port access=1, and intractable pain over port site=1). From the data available, more ports were placed in the left subclavian vein (LSV=20) than right subclavian vein (RSV=4) and right internal jugular (RIJ=2), however rate of overall complications were similar between LSV and RSV - 0.57 complications/1,000 catheter days in LSV and 0.58 complications/1,000 catheter days in RSV. The rate of port associated infection, defined as a positive blood culture drawn from the port, was 0.2 per 1,000 port days. A total of 20 infections identified mostly gram-positive organisms (n=15) predominantly Staphylococcus, compared to gram-negatives (n=3), fungus with Candida albicans (n=1) and a rare acid-fast bacilli infection with Mycobacterium mucogenicum (n=1). The rate of thrombosis, identified radiologically using vascular doppler ultrasound, was 0.03 per 1,000 port days. The rate of premature port removal arising from complications was 0.36 per 1,000 port days. Ports placed for chronic transfusions had a lower rate of removal (0.31 per 1,000 port days) compared to ports placed for poor venous access (0.58 per 1,000 port days) with a ratio of 0.54 which approached statistical significance (p=0.09; CI 0.26-1.21). Conclusion: Ports in pediatric patients with SCD are associated with low rates of thrombosis, infection and malfunction. Ports may be a reasonable alternative for vascular access in patients with SCD - especially in patients who require chronic simple or exchange transfusions and have difficult access. Larger prospective studies will be needed to further assess the scope of use of ports in this population. Disclosures No relevant conflicts of interest to declare.

Comparative genomics of Mycobacterium mucogenicum and Mycobacterium neoaurum clade members emphasizing tRNA and non-coding RNA

BackgroundMycobacteria occupy various ecological niches and can be isolated from soil, tap water and ground water. Several cause diseases in humans and animals. To get deeper insight into our understanding of mycobacterial evolution focusing on tRNA and non-coding (nc)RNA, we conducted a comparative genome analysis of Mycobacterium mucogenicum (Mmuc) and Mycobacterium neoaurum (Mneo) clade members.ResultsGenome sizes for Mmuc- and Mneo-clade members vary between 5.4 and 6.5 Mbps with the complete MmucT (type strain) genome encompassing 6.1 Mbp. The number of tRNA genes range between 46 and 79 (including one pseudo tRNA gene) with 39 tRNA genes common among the members of these clades, while additional tRNA genes were probably acquired through horizontal gene transfer. Selected tRNAs and ncRNAs (RNase P RNA, tmRNA, 4.5S RNA, Ms1 RNA and 6C RNA) are expressed, and the levels for several of these are higher in stationary phase compared to exponentially growing cells. The rare tRNAIleTAT isoacceptor and two for mycobacteria novel ncRNAs: the Lactobacillales-derived GOLLD RNA and a homolog to the antisense Salmonella typhimurium phage Sar RNA, were shown to be present and expressed in certain Mmuc-clade members.ConclusionsPhages, IS elements, horizontally transferred tRNA gene clusters, and phage-derived ncRNAs appears to have influenced the evolution of the Mmuc- and Mneo-clades. While the number of predicted coding sequences correlates with genome size, the number of tRNA coding genes does not. The majority of the tRNA genes in mycobacteria are transcribed mainly from single genes and the levels of certain ncRNAs, including RNase P RNA (essential for the processing of tRNAs), are higher at stationary phase compared to exponentially growing cells. We provide supporting evidence that Ms1 RNA represents a mycobacterial 6S RNA variant. The evolutionary routes for the ncRNAs RNase P RNA, tmRNA and Ms1 RNA are different from that of the core genes.