Drug-resistant Cases Research Articles

Understanding the mechanisms of antimicrobial resistance and potential therapeutic approaches against the Gram-negative pathogen Acinetobacter baumannii.

Globally, the emergence of anti-microbial resistance in pathogens has become a serious threat to human health and well-being. Infections caused by drug-resistant microorganisms in hospitals are associated with increased morbidity, mortality, and healthcare costs. Acinetobacter baumannii is a Gram-negative bacterium belonging to the ESKAPE group and is widely associated with nosocomial infections. It persists in hospitals and survives antibiotic treatment, prompting acute infections such as urinary tract infections, pneumonia, bacteremia, meningitis, and wound-related infections. An innovation void in drug discovery and the lack of new therapeutic measures against A. baumannii continue to afflict infection control against the rising drug-resistant cases. The emergence of drug-resistant A. baumannii strains has also led to the incessant collapse of newly discovered antibiotics. Therefore exploring novel strategies is requisite to give impetus to A. baumannii drug discovery. The present review discusses the bacterial research community's efforts in the field of A. baumannii, focusing on the strategies adapted to identify potent scaffolds and novel targets to bolster and diversify the chemical space available for drug discovery. Firstly, we have discussed existing chemotherapy and various anti-microbial resistance mechanisms in A. baumannii bacterial strains. Next, we elaborate on multidisciplinary approaches and strategies that may be the way forward to combat the current menace caused by the drug-resistant A. baumannii strains. The review highlights the recent advances in drug discovery, including combinational therapy, high-throughput screening, drug repurposing, nanotechnology, and anti-microbial peptides, which are imperative tools to fight bacterial pathogens in the future.

Drug-resistant Tuberculosis in Pediatric

Introduction: Drug-resistant tuberculosis (DR TB) is a condition where Mycobacterium tuberculosis is resistant to isoniazid, rifampicin or resistant to isoniazid and rifampin as well as other first-line anti-tuberculosis drugs (OAT). Tuberculosis (TB) is a contagious infectious disease, caused by Mycobacterium tuberculosis germs where the source of transmission is through droplets containing TB germs. Case Report: A 10 years 7 months girl, came to the MDR Polyclinic at the Haji Adam Malik Medan Central General Hospital (RSUP HAM Medan) on March 21 2023 bringing the results of the TB Molecular Rapid Test (TCM-TB) examination from the Teladan Barat Health Center with Rifampicin results were resistant and on March 24 2023 the patient was hospitalized. Currently, the patient is complaining of a cough that has been experiencing for ± 3 weeks. Cough with the impression of a dry cough and is continuous so that it interferes with daily activities. The cough does not improve even though the patient has taken cough medicine. There is no fever, there is also no history of previous fever. According to the anamnesis from the patient's parents, there has been a weight loss in the last 2 months, around ± 4 kg. There is no family history of long-term cough, but according to parents, there is a neighbor of the patient who suffers from pulmonary TB and is undergoing treatment. Discussion: After the diagnosis of drug-resistant tuberculosis is confirmed, an evaluation is carried out whether the patient meets the criteria for drug-resistant TB treatment guided by short-term or long-term oral drug-resistant tuberculosis. Patients who meet the evaluation criteria for treatment can immediately be given short-term oral drug-resistant tuberculosis therapy. If the patient does not meet the criteria for short-term treatment, long-term drug-resistant tuberculosis treatment is given. Routine evaluations are carried out during treatment and when the results of drug sensitivity tests are available, treatment is adjusted according to the examination results. Conclusion: A case of drug-resistant tuberculosis in a girl aged 10 years 7 months has been reported which was diagnosed based on anamnesis, physical examination, and supporting examinations, there was also a history of close contact with TB sufferers, and the results of TCM examination of sputum fluid showed rifampicin resistant MTB growth. Patients are treated as drug-resistant TB cases with a short-term regimen with regular monitoring of treatment response and side effects.

Impact of a pharmacist-led patient-centred care intervention along with textmessage reminders, on the management of newly diagnosed tubercular patients: A protocol for a randomized controlled trial.

Non-adherence to tuberculosis (TB) treatment is the leading cause of the increase in drug resistance cases. This study will determine the effectiveness of pharmaceutical-care-based interventions coupled with short messages delivered by a pharmacist on treatment outcomes and adherence among TB patients. The study will be conducted in TB Control Center of Pakistan Institute of Medical Sciences Hospital, Islamabad and District Bannu TB Control Center time period will be from August 2019 to September 2021. The patients will be included into the control group (usual care) or the intervention group pharmaceutical care and SMS reminder. The primary outcome includes a change in mean score from baseline in treatment outcomes and adherence, measured by Morisky Medication Adherence Scale, and clinic appointment attendance registration. Secondary outcomes include health-related quality of life of patients, disease knowledge, and patient satisfaction with the intervention. The major issues in patients with TB are cure rate and medication adherence. The method anticipated in this manuscript could set the foundation of pharmaceutical care and mobile SMS for the future provision of care to improve TB treatment outcomes. The study will make available fundamental information about the influence of the patient centered program on the adherence and clinical outcomes of patients with TB.Trial status and registration: Clinical Trials.gov assigned Identifier NCT04645836.

Antifungal Activities of Natural Products and Their Hybrid Molecules.

The increasing cases of drug resistance and high toxicity associated with the currently used antifungal agents are a worldwide public health concern. There is an urgent need to develop new antifungal drugs with unique target mechanisms. Plant-based compounds, such as carvacrol, eugenol, coumarin, cinnamaldehyde, curcumin, thymol, etc., have been explored for the development of promising antifungal agents due to their diverse biological activities, lack of toxicity, and availability. However, researchers around the world are unable to fully utilize the potential of natural products due to limitations, such as their poor bioavailability and aqueous solubility. The development of hybrid molecules containing natural products is a promising synthetic approach to overcome these limitations and control microbes' capability to develop resistance. Based on the potential advantages of hybrid compounds containing natural products to improve antifungal activity, there have been different reported synthesized hybrid compounds. This paper reviews different literature to report the potential antifungal activities of hybrid compounds containing natural products.

Prevalence of genetic polymorphisms ABCB1/ C3435T in patients with epilepsy in Iranian population

Introduction: Epilepsy is a common neurological disorder affecting approximately 1% of the global population. A significant proportion of patients develop drug-resistant epilepsy (DRE), which leads to poor outcomes for treatments and low quality of life. The multidrug transporter P-glycoprotein, encoded by the ABCB1 gene, plays a key role in limiting brain penetration of antiepileptic drugs. The C3435T single nucleotide polymorphism (SNP) in ABCB1 has been linked to variable P-glycoprotein expression and AED response. In this study, the prevalence of C3435T genotypes among epilepsy patients and healthy controls in Fars Province, Iran was investigated. Materials and methods: This study involved 50 patients diagnosed with epilepsy and 100 healthy individuals without a history of seizures or epilepsy. Genotyping was conducted using PCR-RFLP analysis. Results: The variant T allele occurred at a frequency of 52% in cases and 54% in controls. However, no significant association between the C3435T polymorphism and epilepsy risk was observed. Interestingly, it was found that the CT genotype was overrepresented in drug-responsive patients compared to those with drug-resistant cases. This suggests that individuals with the CT genotype may have a more favorable response to antiepileptic drug therapy. Conclusion: These findings suggest that the ABCB1 C3435T variant may play a role in influencing seizure control specifically among Iranian patients, but its effects on susceptibility are minimal. Moreover, individuals with the CT genotype may have a more favorable response to antiepileptic drug therapy. Further research involving larger cohorts is needed to fully understand the impact of ABCB1 genetics on determining individual responses to antiepileptic drugs. Such research could also pave the way for personalized management strategies based on pharmacogenomic testing.

Modeling of malaria vaccine effectiveness on disease burden and drug resistance in 42 African countries

BackgroundThe emergence of antimalarial drug resistance poses a major threat to effective malaria treatment and control. This study aims to inform policymakers and vaccine developers on the potential of an effective malaria vaccine in reducing drug-resistant infections.MethodsA compartmental model estimating cases, drug-resistant cases, and deaths averted from 2021 to 2030 with a vaccine against Plasmodium falciparum infection administered yearly to 1-year-olds in 42 African countries. Three vaccine efficacy (VE) scenarios and one scenario of rapidly increasing drug resistance are modeled.ResultsWhen VE is constant at 40% for 4 years and then drops to 0%, 235.7 (Uncertainty Interval [UI] 187.8–305.9) cases per 1000 children, 0.6 (UI 0.4–1.0) resistant cases per 1000, and 0.6 (UI 0.5–0.9) deaths per 1000 are averted. When VE begins at 80% and drops 20 percentage points each year, 313.9 (UI 249.8–406.6) cases per 1000, 0.9 (UI 0.6–1.3) resistant cases per 1000, and 0.9 (UI 0.6–1.2) deaths per 1000 are averted. When VE remains 40% for 10 years, 384.7 (UI 311.7–496.5) cases per 1000, 1.0 (0.7–1.6) resistant cases per 1000, and 1.1 (UI 0.8–1.5) deaths per 1000 are averted. Assuming an effective vaccine and an increase in current levels of drug resistance to 80% by 2030, 10.4 (UI 7.3–15.8) resistant cases per 1000 children are averted.ConclusionsWidespread deployment of a malaria vaccine could substantially reduce health burden in Africa. Maintaining VE longer may be more impactful than a higher initial VE that falls rapidly.

An agent-based multi-level model to study the spread of gonorrhea in different and interacting risk groups

IntroductionMathematical modeling has emerged as a crucial component in understanding the epidemiology of infectious diseases. In fact, contemporary surveillance efforts for epidemic or endemic infections heavily rely on mathematical and computational methods. This study presents a novel agent-based multi-level model that depicts the transmission dynamics of gonorrhea, a sexually transmitted infection (STI) caused by the bacterium Neisseria gonorrhoeae. This infection poses a significant public health challenge as it is endemic in numerous countries, and each year sees millions of new cases, including a concerning number of drug-resistant cases commonly referred to as gonorrhea superbugs or super gonorrhea. These drug-resistant strains exhibit a high level of resistance to recommended antibiotic treatments.MethodsThe proposed model incorporates a multi-layer network of agents' interaction representing the dynamics of sexual partnerships. It also encompasses a transmission model, which quantifies the probability of infection during sexual intercourse, and a within-host model, which captures the immune activation following gonorrhea infection in an individual. It is a combination of agent-based modeling, which effectively captures interactions among various risk groups, and probabilistic modeling, which enables a theoretical exploration of sexual network characteristics and contagion dynamics.ResultsNumerical simulations of the dynamics of gonorrhea infection using the complete agent-based model are carried out. In particular, some examples of possible epidemic evolution are presented together with an application to a real case study. The goal was to construct a virtual population that closely resembles the target population of interest.DiscussionThe uniqueness of this research lies in its objective to accurately depict the influence of distinct sexual risk groups and their interaction on the prevalence of gonorrhea. The proposed model, having interpretable and measurable parameters from epidemiological data, facilitates a more comprehensive understanding of the disease evolution.

A mathematical analysis of the two-strain tuberculosis model dynamics with exogenous re-infection

The rise of drug resistance has become a major obstacle in treating tuberculosis (TB), significantly contributing to the increasing disease burden. Therefore, it is essential to study the transmission dynamics of the disease, considering the factors that contribute to the strain’s impact on the disease burden, using an epidemiological model. We present a deterministic mathematical model that explores the dynamics of TB with two strains: drug-susceptible and drug-resistant, taking into account exogenous re-infection. We thoroughly analyze to gain insights into the behavior of the model. The qualitative analysis of the model reveals an interesting phenomenon known as “backward bifurcation,” where both stable disease-free and stable endemic equilibria coexist when the associated reproduction number is less than one. In the absence of exogenous re-infection, the model shows the existence of unique positive endemic equilibria. Numerical simulations were conducted, yielding noteworthy results. Increasing the treatment rate for individuals infected with the drug-susceptible strain reduces the number of new cases of drug-susceptible TB while increasing the detection of drug-resistant TB cases. The simulations demonstrate that drug-susceptible and drug-resistant TB strains can coexist when their reproduction numbers exceed one without competitive exclusion occurring. In summary, this study sheds light on the challenges posed by drug resistance in TB treatment and highlights the importance of understanding the disease dynamics through mathematical modeling to develop effective strategies for its control.

Pharmacophore Model-Based Virtual Screening Workflow for Discovery of Inhibitors Targeting Plasmodium falciparum Hsp90.

Plasmodium falciparum causes the most lethal and widespread form of malaria. Eradication of malaria remains a priority due to the increasing number of cases of drug resistance. The heat shock protein 90 of P. falciparum (PfHsp90) is a validated drug target essential for parasite survival. Most PfHsp90 inhibitors bind at the ATP binding pocket found in its N-terminal domain, abolishing the chaperone's activities, which leads to parasite death. The challenge is that the NTD of PfHsp90 is highly conserved, and its disruption requires selective inhibitors that can act without causing off-target human Hsp90 activities. We endeavored to discover selective inhibitors of PfHsp90 using pharmacophore modeling, virtual screening protocols, induced fit docking (IFD), and cell-based and biochemical assays. The pharmacophore model (DHHRR), composed of one hydrogen bond donor, two hydrophobic groups, and two aromatic rings, was used to mine commercial databases for initial hits, which were rescored to 20 potential hits using IFD. Eight of these compounds displayed moderate to high activity toward P. falciparum NF54 (i.e., IC50s ranging from 6.0 to 0.14 μM) and averaged >10 in terms of selectivity indices toward CHO and HepG2 cells. Additionally, four compounds inhibited PfHsp90 with greater selectivity than a known inhibitor, harmine, and bound to PfHsp90 with weak to moderate affinity. Our findings support the use of a pharmacophore model to discover diverse chemical scaffolds such as FM2, FM6, F10, and F11 exhibiting anti-Plasmodium activities and serving as valuable new PfHsp90 inhibitors. Optimization of these hits may enable their development into potent leads for future antimalarial drugs.

Specialized active leprosy search strategies in an endemic area of the Brazilian Amazon identifies a hypermutated Mycobacterium leprae strain causing primary drug resistance.

Leprosy, an infectious disease caused by Mycobacterium leprae, remains a public health concern in endemic countries, particularly in Brazil. In this study, we conducted an active surveillance campaign in the hyperendemic city of Castanhal in the northeastern part of the state of Pará using clinical signs and symptoms combined with serological and molecular tools to diagnose new cases and to identify drug resistance of circulating M. leprae strains and their distribution in the community. During an active surveillance of one week, we enrolled 318 individuals using three different strategies to enroll subjects for this study: (i) an active survey of previously treated cases from 2006 to 2016 found in the Brazil National Notifiable Disease Information System database (n = 23) and their healthy household contacts (HHC) (n = 57); (ii) an active survey of school children (SC) from two primary public schools in low-income neighborhoods (n = 178), followed by visits to the houses of these newly diagnosed SC (n = 7) to examine their HHC (n = 34) where we diagnosed additional new cases (n = 6); (iii) and those people who spontaneously presented themselves to our team or the local health center with clinical signs and/or symptoms of leprosy (n = 6) with subsequent follow-up of their HHC when the case was confirmed (n = 20) where we diagnosed two additional cases (n = 2). Individuals received a dermato-neurological examination, 5 ml of peripheral blood was collected to assess the anti-PGL-I titer by ELISA and intradermal earlobe skin scrapings were taken from HHC and cases for amplification of the M. leprae RLEP region by qPCR. Anti-PGL-I positivity was highest in the new leprosy case group (52%) followed by the treated group (40.9%), HHC (40%) and lowest in SC (24.6%). RLEP qPCR from SSS was performed on 124 individuals, 22 in treated cases, 24 in newly diagnosed leprosy cases, and 78 in HHC. We detected 29.0% (36/124) positivity overall in this sample set. The positivity in treated cases was 31.8% (7/22), while in newly diagnosed leprosy cases the number of positives were higher, 45.8% (11/23) and lower in HHC at 23.7% (18/76). Whole genome sequencing of M. leprae from biopsies of three infected individuals from one extended family revealed a hypermutated M. leprae strain in an unusual case of primary drug resistance while the other two strains were drug sensitive. This study represents the extent of leprosy in an active surveillance campaign during a single week in the city of Castanhal, a city that we have previously surveyed several times during the past ten years. Our results indicate the continuing high transmission of leprosy that includes fairly high rates of new cases detected in children indicating recent spread by multiple foci of infection in the community. An unusual case of a hypermutated M. leprae strain in a case of primary drug resistance was discovered. It also revealed a high hidden prevalence of overt disease and subclinical infection that remains a challenge for correct clinical diagnosis by signs and symptoms that may be aided using adjunct laboratory tests, such as RLEP qPCR and anti-PGL-I serology.

Comorbidity and drug resistance of smear-positive pulmonary tuberculosis patients in the yi autonomous prefecture of China: a cross-sectional study

BackgroundTuberculosis (TB) has a high morbidity and mortality rate, and its prevention and treatment focus is on impoverished areas. The Liangshan Yi Autonomous Prefecture is a typical impoverished area in western China with insufficient medical resources and high HIV positivity. However, there have been few reports of TB and drug resistance in this area.MethodsWe collected the demographic and clinical data of inpatients with sputum smear positive TB between 2015 and 2021 in an infectious disease hospital in the Liangshan Yi Autonomous Prefecture. Descriptive analyses were used for the epidemiological data. The chi-square test was used to compare categorical variables between the drug-resistant and drug-susceptible groups, and binary logistic regression was used to analyse meaningful variables.ResultsWe included 2263 patients, 79.9% of whom were Yi patients. The proportions of HIV (14.4%) and smoking (37.3%) were higher than previously reported. The incidence of extrapulmonary TB (28.5%) was high, and the infection site was different from that reported previously. When drug resistance gene detection was introduced, the proportion of drug-resistant patients became 10.9%. Patients aged 15–44 years (OR 1.817; 95% CI 1.162–2.840; P < 0.01) and 45–59 years (OR 2.175; 95% CI 1.335–3.543; P < 0.01) had significantly higher incidences of drug resistance than children and the elderly. Patients with a cough of ≥ 2 weeks had a significantly higher chance of drug resistance than those with < 2 weeks or no cough symptoms (OR 2.069; 95% CI 1.234–3.469; P < 0.01). Alcoholism (OR 1.741; 95% CI 1.107–2.736; P < 0.05) and high bacterial counts on sputum acid-fast smears (OR 1.846; 95% CI 1.115–3.058; P < 0.05) were significant in the univariate analysis.ConclusionsSputum smear-positive TB predominated in Yi men (15–44 years) with high smoking, alcoholism, and HIV rates. Extrapulmonary TB, especially abdominal TB, prevailed. Recent drug resistance testing revealed higher rates in 15–59 age group and ≥ 2 weeks cough duration. Alcohol abuse and high sputum AFB counts correlated with drug resistance. Strengthen screening and supervision to curb TB transmission and drug-resistant cases in the region.

Utilizing Rapid Molecular Tests (RMT/RIF) in Tuberculosis Drug-Sensitive/Resistant Discovery in Indonesia: A Pilot Study

The underdiagnosis and underreporting of tuberculosis (TB) indicators are unresolved problems. The rapid molecular test (RMT) is one of the breakthroughs for TB case finding by using safer and more sensitive equipment; it is even believed to help find drug-resistant TB. The results of several webinars held regularly by a TB program as well as its evaluation and the use of RMT formed the basis of this study. This initial pilot study aimed to provide an overview of case finding for both drug-sensitive and drug-resistant TB using RMT. A cross-sectional study was conducted on samples in several provinces in Indonesia that have used RMT, both in remote or non-remote island borders areas and fiscal capacity. Regarding the use of RMT for drug-sensitive TB case finding, the largest contributors were males aged above 15 years, while in the drug-resistant TB case finding group, the biggest contributor was the use of RMT in 2017 and 2018. Overall, the findings could only describe the situation in the study area. The use of RMT in drug-sensitive TB case finding would be maximized if the detected cases are males aged above 15 years, while RMT can help find cases of drug-resistant TB.

Comparison of the Severity of Lung Damage on Chest X-ray Between New Drug-Resistant and Drug-Sensitive Cases of Pulmonary Tuberculosis Patients

Background: Drug-resistant (DR) pulmonary tuberculosis (TB) is often associated with morbidity and mortality compared to drug-susceptible (DS) pulmonary TB. The infectiveness and pathological destruction of DR TB and DS TB strains are still controversial. Objectives: This study aimed to compare the severity of lung damage between new cases of DR and DS pulmonary TB. Methods: This was an analytical observational study with a retrospective cross-sectional design. The sample was selected from the medical records of eligible TB patients treated at RSUD Dr. Soetomo, Surabaya (Indonesia) from January 2018 to November 2022. The severity of lung damage was assessed based on the chest X-ray. Results: A total of 319 patients, consisting of 132 new cases of DR pulmonary TB and 187 new cases of DS pulmonary TB, were recruited. The patients had a mean age of 43.64 years old, and 59.5% of them were male. The most common comorbidity was diabetes mellitus. The severity of DR pulmonary tuberculosis is higher in the mild-moderate category (51.5%), while the severity of DS pulmonary tuberculosis is higher in the severe category (77%). Conclusions: There was a difference in lung damage on chest X-ray between new cases of DR and DS pulmonary TB. The severity of DR pulmonary TB was higher in mild-moderate category, while the severity of DS pulmonary TB was higher in severe category.

Molecular markers associated with drug resistance in Plasmodium falciparum parasites in central Africa between 2016 and 2021.

The widespread occurrence of anti-malarial drug resistance threatens the current efforts to control malaria in African regions. Molecular marker surveillance helps to track the emergence and spread of drug-resistant malaria cases. A total of 237 Plasmodium falciparum infections imported from central Africa to Zhejiang Province, China, between 2016 and 2021, were investigated. Genomic DNA was extracted from blood samples of each patient and nested PCRs was used to detect molecular markers in k13, Pfcrt, and Pfmdr1 genes. The spatial and temporal distributions of the molecular markers were analyzed. A limited polymorphism of k13 was observed, including two nonsynonymous (D464E and K503E) and five synonymous mutations. Wild-type CVMNK of Pfcrt predominated (78.5%), whereas 19.5% of the samples harbored the mutant haplotype, CVIET. The point mutation Y184F and the single mutant haplotype NF of Pfmdr1 were the most frequently observed. The geographical distributions of the Pfcrt and Pfmdr1 haplotypes displayed distinct patterns, with the mutant haplotype of Pfcrt more common in Gabon (53.9%) and Congo (50.0%), and wild haplotypes of Pfmdr1 more frequently found in Cameroon, Angola, and Congo. The prevalence of wild-type CVMNK of Pfcrt increased from 68.5-74.6% in 2016-2017 to 81.8-87.5% in 2018-2021. The proportion of wild-type Pfmdr1 also increased from 27.1% in 2016 to 38.5% in 2019. The geographical and temporal distribution of k13, Pfcrt, and Pfmdr1 polymorphisms in P. falciparum parasites imported from central Africa between 2016 and 2021 are demonstrated. Our data provide updated evidence that can be used to adjust anti-malarial drug policies in central Africa and China.

Transmitted drug resistance and transmission clusters among ART-naïve HIV-1-infected individuals from 2019 to 2021 in Nanjing, China.

Transmitted drug resistance (TDR) is an increasingly prevalent problem worldwide, which will significantly compromise the effectiveness of HIV treatments. However, in Nanjing, China, there is still a dearth of research on the prevalence and transmission of TDR among ART-naïve HIV-1-infected individuals. This study aimed to understand the prevalence and transmission of TDR in Nanjing. A total of 1,393 participants who were newly diagnosed with HIV-1 and had not received ART between January 2019 and December 2021 were enrolled in this study. HIV-1 pol gene sequence was obtained by viral RNA extraction and nested PCR amplification. Genotypes, TDR and transmission cluster analyses were conducted using phylogenetic tree, Stanford HIV database algorithm and HIV-TRACE, respectively. Univariate and multivariate logistic regression analyses were performed to identify the factors associated with TDR. A total of 1,161 sequences were successfully sequenced, of which CRF07_BC (40.6%), CRF01_AE (38.4%) and CRF105_0107 (6.3%) were the main HIV-1 genotypes. The overall prevalence of TDR was 7.8%, with 2.0% to PIs, 1.0% to NRTIs, and 4.8% to NNRTIs. No sequence showed double-class resistance. Multivariate logistic regression analysis revealed that compared with CRF01_AE, subtype B (OR = 2.869, 95%CI: 1.093-7.420) and female (OR = 2.359, 95%CI: 1.182-4.707) were risk factors for TDR. Q58E was the most prevalent detected protease inhibitor (PI) -associated mutation, and V179E was the most frequently detected non-nucleoside reverse transcriptase inhibitor (NNRTI) -associated mutation. A total of 613 (52.8%) sequences were segregated into 137 clusters, ranging from 2 to 74 sequences. Among 44 individuals with TDR (48.4%) within 21 clusters, K103N/KN was the most frequent TDR-associated mutation (31.8%), followed by Q58E/QE (20.5%) and G190A (15.9%). Individuals with the same TDR-associated mutations were usually cross-linked in transmission clusters. Moreover, we identified 9 clusters in which there was a transmission relationship between drug-resistant individuals, and 4 clusters in which drug-resistant cases increased during the study period. The overall prevalence of TDR in Nanjing was at a moderate level during the past 3 years. However, nearly half of TDR individuals were included in the transmission clusters, and some drug-resistant individuals have transmitted in the clusters. Therefore, HIV drug-resistance prevention, monitoring and response efforts should be sustained and expanded to reduce the prevalence and transmission of TDR in Nanjing.

Essential Oil Components and Antitrichomonal Effects of Piper nigrum L.

Background: Trichomoniasis, caused by Trichomonas vaginalis protozoan, is the most common nonviral sexually transmitted infection (STI) worldwide. Although metronidazole and tinidazole are the only approved drugs for treatment, drug-resistant cases of infection are on the rise. The aim of this study was the evaluation of antitrichomonal potential of Piper nigrum and limonene. The phytochemical profile of P. nigrum oil was also investigated. Methods: The parasites were treated in vitro with essential oil and different extracts of P. nigrum seed and limonene using microtiter plate method. The oil of P. nigrum was also analyzed by gas chromatography-mass spectrometry and gas chromatography-flame ionization detector. Furthermore, the cytotoxicity assay of P. nigrum oil and limonene were screened on Vero cell line by MTT method. Results: The tested P. nigrum fractions were able to kill 100% of Trichomonas trophozoites at minimum lethal concentration (MLC) and reduce the trophozoite viability at sub-MLC and lower concentrations. After 48 hours exposure, the most potent fraction was the n-hexane extract with MLC of 78 µg/mL followed by the essential oil and methanol extract with MLC of 156 µg/mL, limonene (MLC=1250 µg/mL), and then, aqueous extract with MLC value of 25 mg/mL. Moreover, according to cytotoxicity assay, P. nigrum oil was less toxic to Vero cell than limonene, with a selectivity index (SI) of 13.2 and 2.04, respectively. Conclusion: This study clearly demonstrated the trichomonacidal potential of P. nigrum. Thus, P. nigrum fractions can be considered promising antiprotozoal agents and the basis for further development to discover new phytochemicals compounds.

Molecular Characterization of Class A-ESBLs, Class B-MBLs, Class C-AmpC, and Class D-OXA Carbapenemases in MDR Acinetobacter baumannii Clinical Isolates in a Tertiary Care Hospital, West Bengal, India.

Background Acinetobacter calcoaceticus baumannii (ACB) complex has become a major concern nowadays because of its increasing involvement in several severe infections associated with catheter-related bloodstream and urinary tract infections, ventilator-associated pneumonia, cerebrospinal shunt-related meningitis, and wound infections. Multiple drug-resistant (MDR) ACB cases have been described with an increasing trend where at least it is resistant to a minimum of three antimicrobial groups. The mortality rate associated with A. baumannii is significantly higher than all Acinetobacterspp. isolates with the most prevalence seen in India and Thailand. The rapid spread of high resistance to most potent antimicrobial drugs is due to its ability to incorporate resistance determinants despite multifactorial reasons such as alteration in permeability of cell membrane by either losing expression of outer membrane porins or excess production of efflux pumps. This study aims to characterize resistance determinants responsible for MDR at the genetic level and emphasizes the use of genotyping in routine diagnosis as genotype analysis is reliable and valid. Methodology A total of 289 ACB complex clinical isolates were included in this study. The study for species-level identification of A. baumannii was conducted at the Department of Microbiology, IQ City Medical College Hospital, Durgapur, West Bengal. In addition, the detection of encoded genes associated with class A-extended spectrum beta-lactamases (i.e., CTX-M, KPC, SHV, and TEM genes), class B-metallo-β-lactamases (i.e., IMP, NDM, and VIM genes), Class C-AmpC cephalosporinase, and classD-OXA carbapenemases (i.e., blaOXA-10/11, blaOXA-24, blaOXA-48, blaOXA-58, blaOXA-143, and blaOXA-235was done using real-time polymerase chain reaction. Results All 289 non-repetitive ACB complex clinical isolates were confirmed as A. baumannii, of which 277 (96%) isolates were MDR. There were no findings of blaCTX-M, blaKPC, blaSHV, blaTEM, blaIMP, blaVIM, blaAmpC, blaOXA-10/11, blaOXA-24, blaOXA-48, blaOXA-58, blaOXA-143, and blaOXA-235 genes in our study. However, there were four (1.44%) positive findings of the blaNDM gene. All MDR isolates (n = 277) were positive for the blaOXA-51 gene. In addition, blaOXA-23 was positive in 269 (97.12%) isolates. Conclusions The oxacillinase production corresponding to blaOXA-23 and blaOXA-51 were the most prevalent antibiotic resistance determinants among MDR A. baumanniiin our study. Four (1.44%) isolates had the multiple genes blaOXA-51, blaOXA-23, and blaNDM that shows the coexistence of diverse genetic elements involved in MDR A. baumannii, resulting in total resistance except for a few potent drugs such as colistin and tigecycline. Genotyping is helpful in determining the contribution of the isolates in understanding their association with encoded genes, which, in turn, helps in designing effective surveillance and control strategies in the management of such MDR isolates.

A STUDY OF FUNGAL INFECTIONS IN CLINICALLY SUSPECTED TUBERCULOSIS PATIENTS

Objectives: The purpose of the current study is to create awareness among the clinicians on the role of fungal etiological agents in suspected tuberculosis (TB) cases. This would help in preventing unnecessary use of anti-tubercular drugs and in decreasing drug-resistant TB cases. Methods: Prospective study was performed in the clinical microbiology laboratory of Annapoorana Medical College and Hospital, Salem, Tamil Nadu, from January 2013 to February 2017 subsequently getting approval from the institutional ethics committee. 464 sputum samples were collected from both inpatients and outpatients of numerous departments. Signs and symptoms of clinically suspected TB patients were noted for all cases. Statistical Analysis: Categorical variables were summarized by percentages (%). The Fishers exact test (2 × 2) analysis was done. Results: A total of 119 fungal isolates were isolated from the culture. The highest number of fungal isolates were of Candida species (n=61) (30.5%) followed by Cryptococcus neoformans n=38 (19%) and Histoplasma capsulatum n=20 (10%). Amongst the used anti-fungals, Fluconazole was the most effective drug for all the isolated fungi followed by Itraconazole, Amphotericin B, Voriconazole, and Nystatin. Conclusion: Our study findings indicate the significance of considering fungal infections as a prospect however treating disseminated granulomatous infections, even in immune-competent cases, particularly if the reaction to the TB therapy is insufficient.

Treatment of drug-resistant tuberculosis in children and young adolescents in Brazil

IntroductionDrug-resistant tuberculosis (DR-TB) is a global threat and a challenge for public health authorities worldwide. In children, the diagnosis is even more challenging and DR-TB is poorly described in the literature, as are its treatment outcomes. In this study, we aimed to describe the treatment of drug-resistant TB in children and young adolescents in Brazil. MethodsA descriptive epidemiological study of treatment for DR-TB in children under 15 years of age in Brazil between 2013 and 2020. The primary data source was the Information System for Special Tuberculosis Treatments (SITE-TB). Categorical variables were analyzed using relative frequencies (%) and continuous variables by measures of central tendency to characterize the profile of the cases, namely: sociodemographic, clinical characteristics, procedures, tests performed and treatment success. In order to verify the distribution of cases, a spatial analysis was carried out based on the municipality where the cases resided. ResultsBetween 2013 and 2020, 19,757 tuberculosis (TB) cases occurred in children aged <15 years in Brazil, and 46 cases of treatment for DR-TB were reported during the same period (annual average of 6 cases). Of these, 73.9% were aged 10–14, 65.2% were male, 4.3% were HIV+ and 43.3% were underweight (BMI<18.5) at the start of treatment. 17.4% had previous contact with TB, 69.6% had primary resistance, 47.8% multidrug resistance. The median duration of treatment was 15 months. DOT and standardized treatment regimen were performed in 52.2% of cases. Bacilloscopy was performed for 97.8% (57.8% positive); culture for 89.1% (75.6% positive), rapid molecular test for 73.9% with proven resistance to rifampicin in 55.8%. Susceptibility testing revealed resistance mainly to isoniazid (87.8%) and rifampicin (60.6%). 73.9% of cases were successfully treated and one death was reported. Cases were treated in 26 Brazilian municipalities, with the majority in Rio de Janeiro (15) and São Paulo (4). ConclusionDR-TB treatment was recorded in <1% of general TB cases in children and young adolescents, suggesting underreporting of drug-resistant cases in the country. Despite the low number of registered cases, the data reflect the situation of DR-TB in this population and describe important aspects of the problem, as the child needs comprehensive, individualized care, with support from different professionals. We recommend a strengthening of the country's referral services for the care of children with DR-TB so that surveillance and health care services can work together to identify and follow up cases.

Macrophage targeted polymeric curcumin nanoparticles limit intracellular survival of Mycobacterium tuberculosis through induction of autophagy and augment anti-TB activity of isoniazid in RAW 264.7 macrophages.

Rapid emergence of antibiotic resistance in tuberculosis has left us with limited resources to treat and manage multi drug resistant (MDR) cases of tuberculosis, prompting the development of novel therapeutics. Mycobacterium tuberculosis (MTB) perturbs the host protective pathways for its survival, therefore host directed therapeutic (HDT) interventions offer an attractive alternative strategy. Curcumin (CMN), the principle curcuminoid from Curcuma longa is known to have anti-TB activity against MDR strains of MTB in macrophages. We discovered that treatment of CMN induced autophagy in uninfected and MTB infected macrophages which was evident by conversion of LC3-I to LC3-II and degradation of p62. Inhibition of autophagy by a pharmacological inhibitor 3-MA resulted in significant inhibition of intracellular killing activity of CMN, suggesting the involvement of autophagy in intracellular clearance of MTB. Moreover, annexin v-FITC/PI staining data suggested induction of apoptosis in uninfected and MTB infected macrophages post CMN treatment. This finding was further corroborated by up-regulated expression of pro-apoptotic proteins, Bax, cleaved caspase-3 and PARP and diminished expression of anti-apoptotic protein Bcl-2 as evaluated by immunoblotting. Using GFP-MTB H37Rv and Lysotracker Red staining we demonstrated co-localization of GFP-MTB H37Rv containing phagosome to lysosome after CMN treatment, indicating enhanced phagosome lysosome fusion. Due to poor bioavailability of CMN, its clinical use is limited, therefore to overcome this issue, CMN was encapsulated in Poly(lactic-co-glycolic) acid (PLGA) shell, resulting in polymeric CMN nano particles (ISCurNP). Flow cytometric evaluation suggested >99% uptake of ISCurNP after 3h of treatment. In BALB/c mice, oral dose of ISCurNP resulted in 6.7-fold increase in the bioavailability compared to free CMN. Moreover, ISCurNP treatment resulted in significant decrease in the intracellular survival of MTB H37Rv through induction of autophagy. Adjunct action of ISCurNP and CMN in combination with isoniazid (INH) revealed >99% decrease in intracellular survival of MTB in macrophage as compared to ISCurNP, CMN or INH alone. In conclusion, our findings suggest the role of ISCurNP as novel host directed formulation to combat both sensitive and MDR strains of MTB by induction of autophagy.