Exploring the cellulolytic activity of environmental mycobacteria.

Although studies on non-tuberculous mycobacteria have increased in recent years because they cause a considerable proportion of infections, their cellulolytic system is still poorly studied. This study presents a characterization of the cellulolytic activities of environmental mycobacterial isolates derived from soil and water samples from the central region of Argentina, aimed to evaluate the conservation of the mechanism for the degradation of cellulose in this group of bacteria. The molecular and genomic identification revealed identity with Mycolicibacterium septicum. The endoglucanase and total cellulase activities were assessed both qualitatively and quantitatively and the optimal enzymatic conditions were characterized. A specific protein of around 56 kDa with cellulolytic activity was detected in a zymogram. Protein sequences possibly arising from a cellulase were identified by mass spectrometry-based shotgun proteomics. Results showed that M. septicum encodes for cellulose- and hemicellulose-related degrading enzymes, including at least an active ß-1,4 endoglucanase enzyme that could be useful to improve its survival in the environment. Given the important health issues related to mycobacteria, the results of the present study may contribute to the knowledge of their cellulolytic system, which could be important for their ability to survive in many different types of environments.

Therapeutic vaccines for advanced non-small cell lung cancer.

BACKGROUND: New strategies in immunotherapy with specific antigens that trigger an anti-tumour immune response in people with lung cancer open the possibility of developing therapeutic vaccines aimed at boosting the adaptive immune response against cancer cells. OBJECTIVES: To evaluate the effectiveness and safety of different types of therapeutic vaccines for people with advanced non-small cell lung cancer. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, Wanfang Data, and China Journal Net (CNKI) up to 22 August 2023. SELECTION CRITERIA: We included parallel-group, randomised controlled trials evaluating a therapeutic cancer vaccine, alone or in combination with other treatments, in adults (> 18 years) with advanced non-small cell lung cancer (NSCLC), whatever the line of treatment. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Our primary outcomes were overall survival, progression-free survival, and serious adverse events; secondary outcomes were three- and five-year survival rates and health-related quality of life. MAIN RESULTS: We included 10 studies with 2177 participants. The outcome analyses included only 2045 participants (1401 men and 644 women). The certainty of the evidence varied by vaccine and outcome, and ranged from moderate to very low. We report only the results for primary outcomes here. TG4010 The addition of the vector-based vaccine, TG4010, to chemotherapy, compared with chemotherapy alone in first-line treatment, may result in little to no difference in overall survival (hazard ratio (HR) 0.83, 95% confidence interval (CI) 0.65 to 1.05; 2 studies, 370 participants; low-certainty evidence). It may increase progression-free survival slightly (HR 0.74, 95% CI 0.55 to 0.99; 1 study, 222 participants; low-certainty evidence). It may result in little to no difference in the proportion of participants with at least one serious treatment-related adverse event, but the evidence is very uncertain (risk ratio (RR) 0.70, 95% CI 0.23 to 2.19; 2 studies, 362 participants; very low-certainty evidence). Epidermal growth factor vaccine Epidermal growth factor vaccine, compared to best supportive care as switch maintenance treatment after first-line chemotherapy, may result in little to no difference in overall survival (HR 0.82, 95% CI 0.66 to 1.02; 1 study, 378 participants; low-certainty evidence), and in the proportion of participants with at least one serious treatment-related adverse event (RR 1.32, 95% CI 0.88 to 1.98; 2 studies, 458 participants; low-certainty evidence). hTERT (vx-001) The hTERT (vx-001) vaccine compared to placebo as maintenance treatment after first-line chemotherapy may result in little to no difference in overall survival (HR 0.97, 95% CI 0.70 to 1.34; 1 study, 190 participants). Racotumomab Racotumomab compared to placebo as a switch maintenance treatment post-chemotherapy was assessed in one study with 176 participants. It may increase overall survival (HR 0.63, 95% CI 0.46 to 0.87). It may make little to no difference in progression-free survival (HR 0.73, 95% CI 0.53 to 1.00) and in the proportion of people with at least one serious treatment-related adverse event (RR 1.03, 95% CI 0.15 to 7.18). Racotumomab versus docetaxel as switch maintenance therapy post-chemotherapy was assessed in one study with 145 participants. The study did not report hazard rates on overall survival or progression-free survival time, but the difference in median survival times was very small - less than one month. Racotumomab may result in little to no difference in the proportion of people with at least one serious treatment-related adverse event compared with docetaxel (RR 0.89, 95% CI 0.44 to 1.83). Personalised peptide vaccine Personalised peptide vaccine plus docetaxel compared to docetaxel plus placebo post-chemotherapy treatment may result in little to no difference in overall survival (HR 0.80, 95% CI 0.42 to 1.52) and progression-free survival (HR 0.78, 95% CI 0.43 to 1.42). OSE2101 The OSE2101 vaccine compared with chemotherapy, after chemotherapy or immunotherapy, was assessed in one study with 219 participants. It may result in little to no difference in overall survival (HR 0.86, 95% CI 0.62 to 1.19). It may result in a small difference in the proportion of people with at least one serious treatment-related adverse event (RR 0.95, 95% CI 0.91 to 0.99). SRL172 The SRL172 vaccine of killed Mycobacterium vaccae, added to chemotherapy, compared to chemotherapy alone, may result in no difference in overall survival, and may increase the proportion of people with at least one serious treatment-related adverse event (RR 2.07, 95% CI 1.76 to 2.43; 351 participants). AUTHORS' CONCLUSIONS: Adding a vaccine resulted in no differences in overall survival, except for racotumomab, which showed some improvement compared to placebo, but the difference in median survival time was very small (1.4 months) and the study only included 176 participants. Regarding progression-free survival, we observed no differences between the compared treatments, except for TG4010, which may increase progression-free survival slightly. There were no differences between the compared treatments in serious treatment-related adverse events, except for SRL172 (killed Mycobacterium vaccae) added to chemotherapy, which was associated with an increase in the proportion of participants with at least one serious treatment-related adverse event, and OSE2101, which may decrease slightly the proportion of people having at least one serious treatment-related adverse event. These conclusions should be interpreted cautiously, as the very low- to moderate-certainty evidence prevents drawing solid conclusions: many vaccines were evaluated in a single study with small numbers of participants and events.

Biotransformation of Phytosterols into Androstenedione-A Technological Prospecting Study.

Androstenedione (AD) is a key intermediate in the body's steroid metabolism, used as a precursor for several steroid substances, such as testosterone, estradiol, ethinyl estradiol, testolactone, progesterone, cortisone, cortisol, prednisone, and prednisolone. The world market for AD and ADD (androstadienedione) exceeds 1000 tons per year, which stimulates the pharmaceutical industry's search for newer and cheaper raw materials to produce steroidal compounds. In light of this interest, we aimed to investigate the progress of AD biosynthesis from phytosterols by prospecting scientific articles (Scopus, Web of Science, and Google Scholar databases) and patents (USPTO database). A wide variety of articles and patents involving AD and phytosterol were found in the last few decades, resulting in 108 relevant articles (from January 2000 to December 2021) and 23 patents of interest (from January 1976 to December 2021). The separation of these documents into macro, meso, and micro categories revealed that most studies (articles) are performed in China (54.8%) and in universities (76%), while patents are mostly granted to United States companies. It also highlights the fact that AD production studies are focused on "process improvement" techniques and on possible modifications of the "microorganism" involved in biosynthesis (64 and 62 documents, respectively). The most-reported "process improvement" technique is "chemical addition" (40%), which means that the addition of solvents, surfactants, cofactors, inducers, ionic liquids, etc., can significantly increase AD production. Microbial genetic modifications stand out in the "microorganism" category because this strategy improves AD yield considerably. These documents also revealed the main aspects of AD and ADD biosynthesis: Mycolicibacterium sp. (basonym: Mycobacterium sp.) (40%) and Mycolicibacterium neoaurum (known previously as Mycobacterium neoaurum) (32%) are the most recurrent species studied. Microbial incubation temperatures can vary from 29 °C to 37 °C; incubation can last from 72 h to 14 days; the mixture is agitated at 140 to 220 rpm; vegetable oils, mainly soybean, can be used as the source of a mixture of phytosterols. In general, the results obtained in the present technological prospecting study are fundamental to mapping the possibilities of AD biosynthesis process optimization, as well as to identifying emerging technologies and methodologies in this scenario.

Conjugative transfer of naturally occurring plasmid in Mycolicibacterium sp.

Conjugation is considered the main horizontal gene transfer mechanism in bacterial adaptation and evolution. In the Mycobacteriaceae family, Mycolicibacterium smegmatis has been used as the model organism for the conjugative transfer of hybrid plasmids. However, the natural conjugation process in any bacteria would involve the transfer of naturally occurring plasmids. Currently, there is a gap in this regard about this abundant environmental genus of Mycobacteriaceae. Here, we performed conjugation experiments between wild Mycolicibacterium sp. strains involving naturally occurring plasmids, and interestingly, evidence of conjugative transfer was obtained. Thus, it is likely that conjugation occurs in Mycolicibacterium in the natural environment, representing a source of diversification and evolution in this genus of bacteria.

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.

Whole-Genome sequencing and comparative genomics of Mycobacterium spp. from farmed Atlantic and coho salmon in Chile.

Several members of the Mycobacterium genus cause invasive infections in humans and animals. According to a recent phylogenetic analysis, some strains of Mycobacterium salmoniphilum (Msal), which are the main culprit in bacterial outbreaks in freshwater fish aquaculture, have been assigned to a separate branch containing Mycobacterium franklinii (Mfra), another species that causes infections in humans. However, this genus is little studied in an aquaculture context. Here, we isolated four Mycobacterium spp. strains from freshwater cultures of Atlantic and coho salmon in Chile and performed whole-genome sequencing for deep genomic characterization. In addition, we described the gross pathology and histopathology of the outbreaks. Several bioinformatic analyses were performed using the genomes of these four Mycobacterium isolates in conjunction with those of Msal strains, four Msal-like strains, and one Mfra strains, plus 17 other publicly available Mycobacterium genomes. We found that three isolates are clustered into the Msal branch, whereas one isolate clustered with the Mfra/Msal-like strains. We further evaluated the presence of virulence and antimicrobial resistance genes and observed that the four isolates were closely related to the Msal and Msal-like taxa and carried several antimicrobial resistance and virulence genes that are similar to those of other pathogenic members of the Mycobacterium clade. Altogether, our characterization Msal and Msal-like presented here shed new light on the basis of mycobacteriosis provides quantitative evidence that Mycobacterium strains are a potential risk for aquaculture asetiological agents of emerging diseases, and highlight their biological scopes in the aquaculture industry.

Mycobacterium mageritense infection following mastectomy and breast reconstruction requiring triple antibiotic therapy and surgical debridement.

A 40-year-old woman was referred to infectious disease specialists for a Mycobacterium mageritense skin infection following mastectomy and bilateral reconstruction with deep inferior epigastric perforator flap. Her case demonstrates the difficulty in treating non-tuberculosis mycobacterial infections, especially the rarely seen species. She failed to respond to dual antibiotic therapy containing imipenem-cilastin despite reported sensitivity. Additionally, her course was complicated by intolerance to various regimens, including gastrointestinal distress, a drug rash with eosinophilia and systemic symptoms, and tendinopathy. With few published data, no treatment guidelines, and limited medications from which to choose for M. mageritense, her treatment posed a challenge. She ultimately required aggressive surgical intervention and a triple therapy antibiotic regimen. The duration of our patient's treatment and the extent of her complications suggest a potential need for early surgical intervention in postsurgical wounds infected with M. mageritense that do not respond to conventional treatment.

Comprehensive in silico survey of the Mycolicibacterium mobilome reveals an as yet underexplored diversity.

The mobilome plays a crucial role in bacterial adaptation and is therefore a starting point to understand and establish the gene flow occurring in the process of bacterial evolution. This is even more so if we consider that the mobilome of environmental bacteria can be the reservoir of genes that may later appear in the clinic. Recently, new genera have been proposed in the family Mycobacteriaceae, including the genus Mycolicibacterium, which encompasses dozens of species of agricultural, biotechnological, clinical and ecological importance, being ubiquitous in several environments. The current scenario in the Mycobacteriaceae mobilome has some bias because most of the characterized mycobacteriophages were isolated using a single host strain, and the few plasmids reported mainly relate to the genus Mycobacterium. To fill in the gaps in these issues, we performed a systematic in silico study of these mobile elements based on 242 available genomes of the genus Mycolicibacterium. The analyses identified 156 putative plasmids (19 conjugative, 45 mobilizable and 92 non-mobilizable) and 566 prophages in 86 and 229 genomes, respectively. Moreover, a contig was characterized by resembling an actinomycete integrative and conjugative element (AICE). Within this diversity of mobile genetic elements, there is a pool of genes associated with several canonical functions, in addition to adaptive traits, such as virulence and resistance to antibiotics and metals (mercury and arsenic). The type-VII secretion system was a common feature in the predicted plasmids, being associated with genes encoding virulent proteins (EsxA, EsxB, PE and PPE). In addition to the characterization of plasmids and prophages of the family Mycobacteriaceae, this study showed an abundance of these genetic elements in a dozen species of the genus Mycolicibacterium.

Occurrence of Nontuberculous Mycobacteria, Salmonella, Listeria monocytogenes, and Staphylococcus aureus in Artisanal Unpasteurized Cheeses in the State of Michoacan, Mexico.

ABSTRACT: This study investigated the presence of nontuberculous mycobacteria (NTM) for the first time in two types of unpasteurized fresh cheese produced in the state of Michoacan, Mexico. We tested for this pathogen, along with the others, to broaden the study of microbiological quality in 60 samples of cheese, 30 fresh and 30 Adobera, which were collected from six artisanal cheese factories (ACFs). The hygienic conditions of these establishments and the practices of cheese manufacture were generally poor. Although Mycobacterium bovis was not detected, four cheese samples harbored NTM isolates. The four NTM isolates were identified using three molecular markers (hsp65, rrs, and rpoB genes) that corresponded to Mycolicibacterium fortuitum (n = 3) and Mycolicibacterium mageritense (n = 1). All 60 cheese samples analyzed had unsatisfactory microbiological quality according to the Mexican Official Guideline. Regarding fresh cheeses, all 30 samples analyzed were positive for aerobic mesophilic bacteria, total coliforms, fecal coliforms, and yeasts and molds. Escherichia coli and Staphylococcus aureus were present in 23 and 21 samples, respectively. Listeria monocytogenes was identified in a sample and was isolated from a bulk milk tank in the same ACF. With regard to Adobera cheeses, all samples were positive for aerobic mesophilic bacteria, total coliforms, fecal coliforms, yeasts and molds, and S. aureus. E. coli was isolated from 28 samples. Salmonella was isolated from a sample and from a wooden shovel used in the manufacture of the cheeses in the same ACF. Thus, the consumption of unpasteurized fresh cheese may represent a public health risk. Because of this, health authorities should enforce the legislation that forbids the processing of cheese with unpasteurized milk and encourage producers to follow good manufacturing practices from original ingredients, through the production process of the cheese, to its sale to assure a safe product.

Infectious complications related to medical tourism.

BACKGROUND: Medical tourism has been increasing dramatically globally, with people travelling from developed countries to low-income or middle-income countries, often to avoid high costs or long delays associated with seeking healthcare in their countries of origin. The current review summarizes healthcare-related infections associated with medical tourism, focusing on cosmetic surgery and organ transplantation. METHODS: A systematic MEDLINE and PubMed search from January 2010 to December 2019 yielded 80 relevant articles, including 49 articles on medical tourism-related infections focusing on cosmetic surgery and organ transplantation, which were included in this reviews. RESULTS: The literature reveals specific types of cross-border, healthcare-related infections depending on medical intervention. Destinations include low-income countries such as countries of Asia and the Indian subcontinent, middle-income countries including Central and South America, and high-income countries such as the United States and Europe. In terms of type of infections, in 36 (68%) and 15 (28.3%) studies, wound and blood-borne infections were documented, respectively, while in 21 studies (58.3%) non-tuberculous mycobacteria were isolated, including Mycobacterium abscessus, Mycobacterium chelonae, Mycobacterium senegalense and Mycobacterium fortuitum. The choices of medical tourists could have significant consequences for them and their home countries, including infectious complications and importation of pathogens, particularly antibiotic-resistant microorganisms, with public health implications. CONCLUSIONS: There is a need for public health strategies in order to prevent morbidity and mortality as well as future management and education of patients engaging in medical tourism.

Genomics of Atlantic Forest Mycobacteriaceae strains unravels a mobilome diversity with a novel integrative conjugative element and plasmids harbouring T7SS.

Mobile genetic elements (MGEs) are agents of bacterial evolution and adaptation. Genome sequencing provides an unbiased approach that has revealed an abundance of MGEs in prokaryotes, mainly plasmids and integrative conjugative elements. Nevertheless, many mobilomes, particularly those from environmental bacteria, remain underexplored despite their representing a reservoir of genes that can later emerge in the clinic. Here, we explored the mobilome of the Mycobacteriaceae family, focusing on strains from Brazilian Atlantic Forest soil. Novel Mycolicibacterium and Mycobacteroides strains were identified, with the former ones harbouring linear and circular plasmids encoding the specialized type-VII secretion system (T7SS) and mobility-associated genes. In addition, we also identified a T4SS-mediated integrative conjugative element (ICEMyc226) encoding two T7SSs and a number of xenobiotic degrading genes. Our study uncovers the diversity of the Mycobacteriaceae mobilome, providing the evidence of an ICE in this bacterial family. Moreover, the presence of T7SS genes in an ICE, as well as plasmids, highlights the role of these mobile genetic elements in the dispersion of T7SS.

Diversity of Mycobacteriaceae from aquatic environment at the São Paulo Zoological Park Foundation in Brazil.

We investigated the species diversity of Mycobacteriaceae in surface water samples from six environments at the zoological park in São Paulo, Brazil. Three hundred and eighty isolates were cultivated and identified by phenotypic characteristics (growth rate and pigmentation) and sequencing of hsp65, rpoB and 16S rRNA genes. The results revealed that almost 48% of the isolates could be identified at the species level; about 50% were classified at the genus level, and only less than 2% of the isolates showed an inconclusive identification. The isolates classified at the genus level and not identified were then evaluated by phylogenetic analyses using the same three concatenated target genes. The results allowed us to identify at the genus level some isolates that previously had inconclusive identification, and they also suggested the presence of putative candidate species within the sample, demonstrating that this zoological park is an important source of diversity.

[Electronic cardiovascular device-associated to infective endocarditis caused by Mycobacterium mageritense]. / Endocarditis infecciosa por Mycobacterium mageritense asociada a dispositivo cardíaco electrónico.

Rapidly growing non-tuberculosis mycobacteria are a rare cause of bacterial endocarditis. During the last decades, there has been an increase in infections due to rapidly growing mycobacteria, mainly after trauma and post-surgical procedures, both localized and disseminated, as well as nosocomial outbreaks due to contamination of medical equipment. Routine acid-fast staining for blood culture bottles is not always performed; however, the microbiologist should be aware of potential RGM infections especially when gram positive bacilli are observed. We describe a case of endocarditis caused by Mycobacterium mageritense in a patient with an autologous pericardial patch and a pressure catheter in the left auricle. The bacterial species was identified as Mycobacterium mageritense by mass spectrometry (MALDI-TOF MS), score 2.3, and confirmed by 16S rRNA analysis with 99.8 and 100% agreement, respectively.

Mycobacteria in Minas cheese commercialized in open fairs in São Paulo, Brazil / Mycobacteria em queijos tipo Minas comercializados em feiras-livres de São Paulo, Brasil

Mycobacterium bovis is the causative agent of bovine tuberculosis, a disease that affects dairy herds throughout the Brazilian territory, constituting a neglected zoonosis transmitted by raw milk and its derivatives. In this study, we evaluated the presence of M. bovis and other mycobacteria in Minas cheese obtained from open fairs in the city of São Paulo between 2012 and 2013. Samples (n = 133) were decontaminated using hexa-cetylpyridinium chloride and seeded on StonebrinkLeslie medium. The isolates were submitted to molecular identification by TB Multiplex PCR targeting the 16S rRNA gene and amplicon nucleotide sequencing. From 16 cheese samples (12%), we obtained 26 putative colonies of Mycobacterium spp., none of which belonged to any of the Mycobacterium tuberculosis, Mycobacterium avium, or Mycobacterium intracellulare complexes. Phylogenetic analysis showed that sample sequences were grouped in a clade that includes only non-tuberculous mycobacteria with proximity to sequences obtained from Mycobacterium novocastrense (3 sequences), Mycobacterium holsaticum (1 sequence), andMycobacterium elephantis (2 sequences). Although no epidemiological evidence was found regarding the importance of oral transmission of mycobacteria in healthy people, their importance in the immunosuppressed population remains uncertain.(AU)

Mycobacterium bovis é o agente da tuberculose bovina, doença que acomete o rebanho em todo território brasileiro e é uma negligenciada zoonose transmitida pelo leite e seus derivados. Este trabalho avaliou a presença de M. bovis e outras micobactérias, em queijo minas meia-cura, obtidos em feiras-livres na cidade de São Paulo, entre os anos de 2012 e 2013. As amostras (n = 133) foram descontaminadas pelo método HPC (hexa-cetyl-pyridinium chloride) e semeadas em meio Stonebrink Leslie. Os isolados foram submetidos à identificação molecular por PCR TB multiplex, pesquisando-se o gene 16S rRNA, e ao sequenciamento nucleotídico. Dezesseis amostras (12%) possuiam 26 colônias sugestivas de Mycobacterium spp., mas nenhuma delas pertencia aos complexos Mycobacterium tuberculosis, Mycobacterium avium e Mycobacterium intracellulare. A análise filogenética mostrou que todas as amostras estavam agrupadas em clados que incluem apenas micobactérias não tuberculosas (MNT), sendo que algumas possuiam proximidade com sequências obtidas de Mycobacterium novocastrense (3 sequências), Mycobacterium hosaticum (1 sequência) e Mycobacterium elephantis (2 sequências). Embora no momento não haja evidência epidemiológica da importância da transmissão oral das micobactérias pra indivíduos saudáveis, sua importância na população imunossuprimida ainda é incerta.(AU)

Environmental mycobacteria: a threat to human health?

In many cases, bacterial pathogens are close relatives to nonpathogens. Pathogens seem to be limited lineages within nonpathogenic bacteria. Nonpathogenic isolates are generally more diverse and widespread in the environment and it is generally considered that environmental bacteria do not pose a risk to human health as clinical isolates do; this may not be the case with mycobacteria, but environmental mycobacteria have not been well studied. It is documented that several environmental mycobacteria constitute a source for human infections. Diverse mycobacterial environmental isolates are rarely involved in human disease. Environmental mycobacteria may have a role in degradation of different compounds. Environmental mycobacteria have had a long interaction with humans, maybe as long as the human species, and may have contributed to human evolution.

Altered production of IFN-gamma? And other inflammation-related cytokines by mycobacteria- stimulated peripheral blood mononuclear cells from rheumatoid arthritis patients.

Peripheral blood mononuclear cells taken from 32 patients with Rheumatoid Arthritis (RA) receiving neither steroids nor methotrexate and 34 healthy controls were examined for lymphoproliferation in the presence of ultrasonic extracts of 14 different mycobacterial species or serotypes, of an extract of Candida albicans and of 2 mitogens. Additionally, cells were incubated for 96 hours alone, or with Mycobacterium tuberculosis (M.tb) sonicate or Concanavalin-A (Con-A), and supernatants were tested for a range of cytokines. Lymphocytes of rheumatoid patients were less reactive than controls to all the mycobacterial preparations, but no different in their responses to mitogens. Stimulation of patients' cells with M.tb sonicate induced significantly less interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) but more transforming growth factor- beta (TGF-beta) than controls. Even stimulation with Con-A induced much less IFN-gamma in patient's cells than in those of controls. The combination of reduced responses to the mycobacterial reagents and reduced stimulation of type 1 cytokines by the sonicate of M.tb, suggests reduced responsiveness to group i, common mycobacterial antigens. Such findings need not indicate involvement of mycobacteria specifically in the disease aetiology, but provide novel information on the immunopathological abnormalities, which may explain the reported increased susceptibility to mycobacteria of RA patients.

Cord formation and colony morphology for the presumptive identification of Mycobacterium tuberculosis complex

The identification of Mycobacterium tuberculosis complex (MT), using non-molecular methods, is time-consuming. The objective of this study was to evaluate a screening test for the presumptive identification of MT, which could potentially decrease laboratory turn-around time for reporting preliminary results. From January 1998 to December 1999, 3056 cultures were analysed at the Mycobacterial Laboratory, Instituto Adolfo Lutz, S los o Paulo, Brasil. The screening test consisted of observation of colony morphology on L que wenstein Jensen medium and evaluation of cord formation on smear microscopy from those positive cultures. After the screening test, the cultures identified as non-tuberculous mycobacteria were identified to species by conventional methods (growth on culture and biochemical tests). Those identified as MT were submitted to drug susceptibility tests. The presumptive identification of MT using the proposed screening test, when compared with conventional tests, presented 98.9, 86.9, 97.8 and 93.0 percent of sensitivity, specificity, positive and negative predictive values, respectively. The conclusion is that it is possible to make a presumptive identification of MT using visual analysis of colony morphology and cord formation on microscopy examination. This method could be used to report the presumptive identification of MT and to guide laboratory decisions regarding susceptibility and identification tests with little cost and in a very practical way.

Quality assurance in relation to mycobacterial sputum samples received and processed at the National Public Health laboratory, 1st August 1997 to 31st January, 1998 and the effect of patients' treatment

There has been a global increase in the incidence of mycobacterial cases since the advent of HIV and AIDS. This increase has not been seen in Jamaica. This study was done to determine the quality of sample received, at the National Public Laboratory, in terms of sputum/saliva and time submitted after collection, and to evaluate if this affected case treatment. Data was retrospectively extracted from bench records at the laboratory and analyzed. Cross checking of laboratory negative and positive cases was done using patients' record at the National Chest Hospital, to validate laboratory results with clinical diagnosis. Evaluation of treatment of positive cases with respect to sensitivity results was done. Results showed that of the 925 sputum submitted 86.6 percent were true sputum samples, submitted mainly from the urban region. Sputum samples were five times more likely to yield positive TB culture results than saliva. There was no statistically significant difference in mycobacteria other than tuberculosis (MOTT) or contamination results between sputum and saliva. With respect to time of arrival, only 412 samples were analyzed due to lack of data. Of these, 56.1 percent of these arrived within one day. Postive TB cultures were no different among sputum (14.3 percent) and saliva (13.3 percent) samples with respect to time of arrival. Contamination rate was slightly higher in samples received > 1 day (4.4 percent), to those received within one day (2.2 percent). The treatment of 22 TB positive cases evaluated, corresponded with the sensitivity results, but only one of the three MOTT cases corresponded. The quality of sputum samples received was generally good, and did not significantly affect culture results and patients' treatment. A further study however, needs to be done to evaluate quality control measures in the laboratory.(AU)