26 research outputs found
Evaluation of the antimicrobial activity of Cinnamomum zeylanicum essential oil and trans-Cinnamaldehyde against resistant Mycobacterium tuberculosis
The essential oil (EO) extracted from the bark of Cinnamomum zeylanicum (Czey; also known as cinnamon), mostly derives its properties from its major compound trans-cinnamaldehyde (TCin). The present study evaluated the antimycobacterial activity of the essential oil from Czey (CzeyEO) and TCin against sensitive and resistant clinical isolates of Mycobacterium tuberculosis, as well as the combinatorial effects of CzeyEO and TCin with the anti-tuberculosis (TB) drugs rifampicin (RIF) and isoniazid (INH). The resazurin microtiter assay method was used to determine the minimum inhibitory concentration (MIC) of the components tested on the clinical isolates of M. tuberculosis. The effects of the CzeyEO/RIF, CzeyEO/INH, TCin/RIF, and TCin/INH combinations on the M. tuberculosis H37Rv reference strain were evaluated using the checkerboard method to determine the fractional inhibitory concentration index (FICI). CzeyEO and TCin inhibited all bacterial clinical isolates. In the interactive experiment, CzeyEO and TCin were found to be highly effective in reducing the resistance of resistant M. tuberculosis to RIF and INH. All four tested combinations demonstrated synergistic and additive effects, with no antagonistic effects. The synergistic combinations of CzeyEO/RIF and CzeyEO/INH exhibited FICI values of 0.375 and 0.5, respectively, while the TCin/RIF and TCin/INH combinations exhibited FICI values of 0.31 and 0.5, respectively. These results indicate that CzeyEO and TCin are potential candidates for the treatment of drug-resistant tuberculosis in combination therapy with INH and RIF
Widespread nasal carriage of Mycobacterium lepraeamong a healthy population in a hyperendemic region of northeastern Brazil.
A case-control study was conducted to determine the presence ofMycobacterium lepraeDNA in nasal secretions of leprosy cases and nonleprosy individuals in Fortaleza, Brazil. It included 185 cases identified by physicians at the Dona Libânia National Reference Centre for Sanitary Dermatology (CDERM). A control group (Co) (n = 136) was identified among individuals from CDERM not diagnosed as leprosy cases. To augment the spatial analysis of M. leprae specific repetitive element (RLEP) positive prevalence, an external group (EG) (n = 121), a convenience sample of healthy students, were included. Polymerase chain reaction for the RLEP sequence was conducted for all participants. Prevalence of RLEP positivity for cases and Co were 69.2% and 66.9%, respectively, significantly higher than for EG (28.1%), and reported elsewhere. Male sex, belonging to a lower socioeconomic status (D/E), history of a previous contact with a case and being older, were associated with being a leprosy case. Our geographical analysis demonstrated that the bacillus is widespread among the healthy population, with clusters of RLEP positive multibacillary cases concentrated in distinct areas of the city. Our results suggest that in endemic areas, as in Fortaleza, surveillance for both nonhousehold leprosy contacts and members of the general population living in cluster areas should be implemented
Molecular characterization of pre-extensive drug resistant Mycobacterium tuberculosis in Northeast Brazil
In Fortaleza, the capital of Ceara State, Brazil, the detection rate of tuberculosis (TB) in 2018 was 65.5/100,000 inhabitants with a cure rate of 59.1%, which is higher than the country average. This study investigated the risk factors associated with drug-resistant tuberculosis (DR-TB) and identified the drug-resistance phenotype and resistance-conferring mutations. The geographic distribution of DR-TB in Fortaleza, Brazil, was also determined. From March 2017 to February 2018, 41 DR-TB isolates and 69 drug-susceptible pulmonary TB isolates were obtained from patients seen at a referral hospital in Fortaleza, Brazil. Samples were subjected to phenotypic and genetic analysis of resistance; the spatial distribution of the participants was also analyzed. Primary resistance was high (50.9%) among participants. The following risk factors for DR were identified: being female (p = 0.03), having diabetes (p < 0.01), history of previous TB disease (p < 0.01), and the number of intra-domiciliary contacts (p < 0.01). Analysis by multiplex allele-specific polymerase chain reaction detected mutations in the genes katG (65.8%), rpoB (43.9%), inhA promoter (14.6%), and gyrA (9.8%). Sequencing identified mutations in the the genes katG (75.6%), inhA promoter (19.5%), rpoB (85.4%), and gyrA (100%). There was no mutation in the rrs gene. Spatial analysis showed DR-TB isolates distributed in areas of low socioeconomic status in the city of Fortaleza. Our results emphasized the importance of detecting resistance to TB drugs. The resistance found in the gene gyrA is of concern due to the high number of pre-extensive DR-TB cases in Fortaleza
Widespread nasal carriage of Mycobacterium lepraeamong a healthy population in a hyperendemic region of northeastern Brazil
Staphylococcus aureus (MRSA and CA-MRSA strains) in South America: comparative review to emergence of strains in North America and worldwide
Background: In the last few years, 3 different strains of MRSA have emerged: Community-associated Methicillin-resistant S. aureus (CA-MRSA), Hospital-associated (HA-MRSA), and Livestock-associated (LA-MRSA). The most common CA-MRSA strain is USA 300 lineage. In Brasil, this superbacteria is an important public health problem, once they are associated with severe infections (sepsis, shock and osteomyelitis), high mortality rates (including babies) and low response to usual treatments. Aim: To review attempts to compare CA-MRSA strains in South America and propose an interconnection with patterns of North America and worldwide strains. Methods: Non-systematic review. Findings: Epidemiological and Genotyping definitions were used to compare different strains in different continents. Thus, we could determine ST30+ as the most common lineage in the Brazil and South America, USA 300 lineage as the most common in North America and ST80+ as the most common in Europe. Conclusion: MRSA is a seriously public health problem in Brazil and worldwide. In few years scientist will need a better understand of bacteria-derived factors that participate in enhanced MRSA pathogenesis & host susceptibility. Also, scientists will need to improve tools for an early diagnosis and they will need to enhance preventative/therapeutic modalities. However, new challenges will keep emerging
Antimicrobial activity of essential oils from Lippia alba, Lippia sidoides, Cymbopogon citrates, Plectranthus amboinicus, and Cinnamomum zeylanicum against Mycobacterium tuberculosis
ABSTRACT: The rise in cases of antibiotic-resistant Mycobacterium tuberculosis has become a major obstacle to the effective control of tuberculosis (TB) worldwide. Essential oils (EO) are complex mixtures that may contain between 20 and 60 components, with two or three major compounds at relatively high concentrations (20-70%) that are responsible for their pharmacological properties. The objective of this study was to assess the antimicrobial activity of the EOs, bushy lippia (Lippia alba), rosemary pepper (Lippia sidoides), lemon grass (Cymbopogon citratus), Mexican mint or Indian borage (Plectranthus amboinicus), and true cinnamon (Cinnamomum zeylanicum), against Mycobacterium tuberculosis H37Rv. Chemical characterization of the EOs was performed by gas chromatography coupled to mass spectrometry. The minimum inhibitory concentration (MIC) was determined by the microdilution-based resazurin microtiter assay. Four EOs were able to inhibit the growth of M. tuberculosis, with MICs of 286.5±130.2μg/mL (C. zeylanicum), 299.5±117.2μg/mL (L. sidoides), 351.6±39.06μg/mL (P. amboinicus), and 1,250μg/mL (C. citratus). Only the EO of L. alba showed no antimycobacterial activity at the tested concentrations, with an MIC greater than 1,250µg/mL. Results of this study suggested that C. zeylanicum, L. sidoides, and P. amboinicus could be important sources of bactericidal compounds against M. tuberculosis and require further investigation. The activity against M. tuberculosis of these three EOs has not been reported previously. The results show the high potential of the tested antimycobacterial EOs, making them a promising alternative for TB treatment. This data also confirms the importance of bioprospecting studies for active substances with antimycobacterial activity, which are still scarce
Factors related to HIV/tuberculosis coinfection in a Brazilian reference hospital
Infection with both Human Immunodeficiency Virus (HIV) and Mycobacterium tuberculosis is currently the world's leading cause of death due to infectious agents. We evaluated factors related to the development of tuberculosis (TB) in HIV-infected patients who were being treated at an infectious diseases hospital in Fortaleza, Ceará, Brazil. From January 2004 to December 2005, we made an epidemiological study through the analysis of the medical records of 171 patients, who were diagnosed as having both HIV and tuberculosis. Among these co-infected patients, most (81%, p=0.0006) were male. Co-infection was more frequent (87.8%) among patients over 40 years of age and those with lower educational levels (less than eight years of schooling). Forty-one percent of the patients in the study had not had a smear culture test for acid-fast bacilli (AFB). CD4 cell counts were lower than 200 cells/µL in 71.9% of the patients, the mean being 169 cells/µL. This type of data is important for establishing strategies to improve the control of tuberculosis in HIV-infected patients
Human-armadillo interaction in Ceará, Brazil: Potential for transmission of Mycobacterium leprae.
Several factors suggest that armadillos present an important risk for human leprosy infection. This study uses semi-structured interviews to better illustrate how human interaction with armadillos may increase the risk of leprosy transmission. The participants were all residents of the state of Ceará, in northeastern Brazil, all acknowledged contact with armadillos either through hunting, through cooking, or through consumption of its meat. This study raises important issues about contact between human beings and armadillos. The interviews provide evidence of numerous situations in which leprosy transmission via the armadillo is possible. At a minimum, people who hunt armadillos need to be made aware of the risk of infection
Serum levels of interleukin-6 in contacts of active pulmonary tuberculosis
INTRODUCTION: It is estimated that over two billion individuals are infected by Mycobacterium tuberculosis worldwide. Interleukin-6 (IL-6) is an important cytokine whose serum levels are commonly high in active pulmonary tuberculosis (TB). IL-6 screening in contacts of patients with TB may be useful to monitor the progress of the infectious process and to infer the risk of progression to active disease. OBJECTIVE: To evaluate the serum levels of interleukin-6 in contacts of patients with active pulmonary tuberculosis and to compare them with two other groups: a) patients affected by active pulmonary tuberculosis; b) non-contacts of tuberculosis. METHODS: Cross-sectional study with 15 contacts of patients with active pulmonary tuberculosis, selected according to the protocol recommended by the Ministry of Health. The serum levels of interleukin-6 were measured by Enzyme-linked immunosorbent assay (ELISA). The same test was also applied in the two comparison groups: 38 patients with active pulmonary tuberculosis (confirmed by clinical examination, X-rays of the chest and baciloscopy) and 63 non-contacts (healthy blood donors). RESULTS: In the contact group, the median IL-6 concentration was 1.7 pg/ml (0.96-4.8 pg/ml). For those affected by active pulmonary tuberculosis and non-contact individuals, these values corresponded to 4.3 pg/ml (0.5-24 pg/ml) and 0.5 pg/ml (0-2.8 pg/ml), respectively (p < 0.0001). CONCLUSION: Contacts of patients with active pulmonary tuberculosis had significantly higher IL-6 serum levels (3.4 times higher) in relation to non-contact individuals, but on a lower level (2.5 times lower) when compared to those affected by active disease