OBJECTIVE

To determine the prevalence of rectal colonization with carbapenem-resistant organisms (CRO) among PGH neonatal intensive care unit (NICU) patients.

A prospective single-center observational study conducted over a 1-month period included all NICU 3 and cohort area patients admitted on April 24, 2024. Rectal swabs were collected for multidrug-resistant organism (MDRO) screening and repeated weekly for 1 month while admitted. Swabs were inoculated on chromogenic media, and isolates were identified and tested for antimicrobial sensitivity by disk diffusion. Clinical characteristics and outcomes were collected for 30 days from initial MDRO screening. Descriptive statistics were used to summarize the data.

The point prevalence of CRO colonization was 37% (14 of 38) at initial screening. There were 14 incident colonizations, hence the 4-week period prevalence of CRO colonization was 72.5% (29 of 40). The patients were mostly very preterm, very low birth weight neonates, majority were tested within the first 2 weeks of life, and half were exposed to meropenem at initial screening. Nosocomial infection developed in 29% and 64%, and 30-day mortality rate was 8% and 21% among initially non-CRO-colonized and CRO-colonized patients respectively. Despite high CRO colonization, no culture-proven CRO infection was observed. Surveillance screening documented persistent CRO colonization in 37%, but no decolonization. Escherichia coli, Klebsiella spp. and Serratia spp. were the most common colonizers.

The high prevalence of rectal CRO colonization in the NICU emphasizes the burden of antimicrobial resistance, but despite the high CRO colonization, no CRO infection was documented from the limited sample and study period.

BACKGROUND AND OBJECTIVE

Antimicrobial resistance (AMR) is a leading global public health concern as it resulted in more difficult-to-treat infections and fatalities. In the Philippines, drug-resistant E. coli, including multidrug-resistant (MDR), extended-spectrum beta-lactamase (ESBL)-producing, carbapenemase-producing carbapenem-resistant (CP-CR) E. coli, have been isolated from common food animals, increasing the risk of cross-contamination between humans, animals, and the environment. However, there is a lack of data on the distribution of E. coli in chicken meat in public wet markets. This study aims to describe the AMR profile of E. coli in raw chicken meat from retail stalls in a selected wet market in Manila City.

This quantitative descriptive study characterized the AMR profile of E. coli isolated from 25 raw chicken meat samples from a wet market in Manila City. Antimicrobial susceptibility was determined through disk diffusion method against 23 antimicrobial agents in 16 antimicrobial classes. MDR E. coli were identified based on the resistance patterns. ESBL- and carbapenemase-producing capacities of the bacteria were tested through double disk synergy test and modified carbapenem inactivation method, respectively.

Twenty-four out of 25 (96%) chicken samples contained E. coli isolates. Of these, 23 (96%) were classified as MDR. High resistance rates were observed against ampicillin (92%), tetracycline (88%), trimethoprim-sulfamethoxazole (83%), chloramphenicol (79%), ampicillin-sulbactam (75%), amoxicillin-clavulanic acid (67%), fosfomycin (67%), and streptomycin (54%). The majority of the E. coli isolates were still susceptible to a wide range of selected antimicrobial agents, including carbapenems (100%), ceftriaxone (100%), cefepime (100%), cefuroxime (96%), cefotaxime (96%), ceftazidime (96%), piperacillin-tazobactam (96%), aztreonam (96%), cefoxitin (92%), and nitrofurantoin (83%), among others. Meanwhile, none of the 24 isolated E. coli samples were classified as ESBL- and CP-CR E. coli.

Among the 25 chicken samples, 24 E. coli colonies were isolated that exhibited 0% to 92% resistance rates against selected antimicrobial agents. Most isolates were classified as MDR, but none were considered ESBLand CP-CR E. coli. This study suggests that chickens in wet markets can potentially serve as reservoir hosts for drugresistance genes, which could transfer to other bacteria and contaminate humans, animals, and the environment within the food production and supply chain. These findings emphasize the need for AMR surveillance and strategies to combat AMR in the Philippines through the One Health approach.

Background and Objective: Antimicrobial resistance (AMR) is a leading global public health concern as it resulted in more difficult-to-treat infections and fatalities. In the Philippines, drug-resistant E. coli, including multidrug-resistant (MDR), extended-spectrum beta-lactamase (ESBL)-producing, carbapenemase-producing carbapenem-resistant (CP-CR) E. coli, have been isolated from common food animals, increasing the risk of cross-contamination between humans, animals, and the environment. However, there is a lack of data on the distribution of E. coli in chicken meat in public wet markets. This study aims to describe the AMR profile of E. coli in raw chicken meat from retail stalls in a selected wet market in Manila City. Methods: This quantitative descriptive study characterized the AMR profile of E. coli isolated from 25 raw chicken meat samples from a wet market in Manila City. Antimicrobial susceptibility was determined through disk diffusion method against 23 antimicrobial agents in 16 antimicrobial classes. MDR E. coli were identified based on the resistance patterns. ESBL- and carbapenemase-producing capacities of the bacteria were tested through double disk synergy test and modified carbapenem inactivation method, respectively. Results: Twenty-four out of 25 (96%) chicken samples contained E. coli isolates. Of these, 23 (96%) were classified as MDR. High resistance rates were observed against ampicillin (92%), tetracycline (88%), trimethoprim-sulfamethoxazole (83%), chloramphenicol (79%), ampicillin-sulbactam (75%), amoxicillin-clavulanic acid (67%), fosfomycin (67%), and streptomycin (54%). The majority of the E. coli isolates were still susceptible to a wide range of selected antimicrobial agents, including carbapenems (100%), ceftriaxone (100%), cefepime (100%), cefuroxime (96%), cefotaxime (96%), ceftazidime (96%), piperacillin-tazobactam (96%), aztreonam (96%), cefoxitin (92%), and nitrofurantoin (83%), among others. Meanwhile, none of the 24 isolated E. coli samples were classified as ESBL- and CP-CR E. coli. Conclusion Among the 25 chicken samples, 24 E. coli colonies were isolated that exhibited 0% to 92% resistance rates against selected antimicrobial agents. Most isolates were classified as MDR, but none were considered ESBLand CP-CR E. coli. This study suggests that chickens in wet markets can potentially serve as reservoir hosts for drugresistance genes, which could transfer to other bacteria and contaminate humans, animals, and the environment within the food production and supply chain. These findings emphasize the need for AMR surveillance and strategies to combat AMR in the Philippines through the One Health approach.
drug resistance ; multi-drug resistance ; drug resistance, multiple ; carbapenemase ; Escherichia coli

Tuberculosis (TB) is an ancient infectious disease. Before the availability of effective drug therapy, it had high morbidity and mortality. In the past 100 years, the discovery of revolutionary anti-TB drugs such as streptomycin, isoniazid, pyrazinamide, ethambutol and rifampicin, along with drug combination treatment, has greatly improved TB control globally. As anti-TB drugs were widely used, multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis emerged due to acquired genetic mutations, and this now presents a major problem for effective treatment. Genes associated with drug resistance have been identified, including katG mutations in isoniazid resistance, rpoB mutations in rifampin resistance, pncA mutations in pyrazinamide resistance, and gyrA mutations in quinolone resistance. The major mechanisms of drug resistance include loss of enzyme activity in prodrug activation, drug target alteration, overexpression of drug target, and overexpression of the efflux pump. During the disease process, Mycobacterium tuberculosis may reside in different microenvironments where it is expose to acidic pH, low oxygen, reactive oxygen species and anti-TB drugs, which can facilitate the development of non-replicating persisters and promote bacterial survival. The mechanisms of persister formation may include toxin-antitoxin (TA) modules, DNA protection and repair, protein degradation such as trans-translation, efflux, and altered metabolism. In recent years, the use of new anti-TB drugs, repurposed drugs, and their drug combinations has greatly improved treatment outcomes in patients with both drug-susceptible TB and MDR/XDR-TB. The importance of developing more effective drugs targeting persisters of Mycobacterium tuberculosis is emphasized. In addition, host-directed therapeutics using both conventional drugs and herbal medicines for more effective TB treatment should also be explored. In this article, we review historical aspects of the research on anti-TB drugs and discuss the current understanding and treatments of drug resistant and persistent tuberculosis to inform future therapeutic development.
Humans ; Pyrazinamide/therapeutic use* ; Isoniazid/therapeutic use* ; Antitubercular Agents/therapeutic use* ; Tuberculosis, Multidrug-Resistant/microbiology* ; Mycobacterium tuberculosis/genetics* ; Tuberculosis/drug therapy* ; Rifampin/therapeutic use* ; Mutation ; Drug Resistance, Multiple, Bacterial/genetics*

OBJECTIVE: To investigate the effect of adipocytes in the bone marrow microenvironment of patients with multiple myeloma (MM) on the pathogenesis of MM. METHODS: Bone marrow adipocytes (BMA) in bone marrow smears of health donors (HD) and newly diagnosed MM (ND-MM) patients were evaluated with oil red O staining. The mesenchymal stem cells (MSC) from HD and ND-MM patients were isolated, and in vitro co-culture assay was used to explore the effects of MM cells on the adipogenic differentiation of MSC and the role of BMA in the survival and drug resistance of MM cells. The expression of adipogenic/osteogenic differentiation-related genes PPAR-γ, DLK1, DGAT1, FABP4, FASN and ALP both in MSC and MSC-derived adipocytes was determined with real-time quantitative PCR. The Western blot was employed to detect the expression levels of IL-6, IL-10, SDF-1α, TNF-α and IGF-1 in the supernatant with or without PPAR-γ inhibitor. RESULTS: The results of oil red O staining of bone marrow smears showed that BMA increased significantly in patients of ND-MM compared with the normal control group, and the BMA content was related to the disease status. The content of BMA decreased in the patients with effective chemotherapy. MM cells up-regulated the expression of MSC adipogenic differentiation-related genes PPAR-γ, DLK1, DGAT1, FABP4 and FASN, but the expression of osteogenic differentiation-related gene ALP was significantly down-regulated. This means that the direct consequence of the interaction between MM cells and MSC in the bone marrow microenvironment is to promote the differentiation of MSC into adipocytes at the expense of osteoblasts, and the cytokines detected in supernatant changed. PPAR-γ inhibitor G3335 could partially reverse the release of cytokines by BMA. Those results confirmed that BMA regulated the release of cytokines via PPAR-γ signal, and PPAR-γ inhibitor G3335 could distort PPAR-γ mediated BMA maturation and cytokines release. The increased BMA and related cytokines effectively promoted the proliferation, migration and drug resistance of MM cells. CONCLUSION The BMA and its associated cytokines are the promoting factors in the survival, proliferation and migration of MM cells. BMA can protect MM cells from drug-induced apoptosis and plays an important role in MM treatment failure and disease progression.
Humans ; Osteogenesis/genetics* ; Bone Marrow/metabolism* ; Multiple Myeloma/metabolism* ; Drug Resistance, Neoplasm ; Peroxisome Proliferator-Activated Receptors/pharmacology* ; Cell Differentiation ; Adipogenesis ; Cytokines/metabolism* ; Adipocytes/metabolism* ; Bone Marrow Cells/metabolism* ; Cells, Cultured ; PPAR gamma/pharmacology* ; Tumor Microenvironment

OBJECTIVE: To investigate the mechanism of drug reversing resistance of Agaricus blazei extract FA-2-b-β on T cell acute lymphoblastic leukemia (T-ALL) cell lines. METHODS: Cell proliferation was detected by CCK-8 assay; the apoptosis, cell cycle mitochondrial membrane potential, and intracellular rhodamine accumulation were detected by flow cytometry, and apoptosis-related gene and protein expression were detected by qPCR and Western blot; the membrane surface protein MDR1 was observed by immunofluorescence microscopy. RESULTS: Different concentrations of FA-2-b-β significantly inhibited proliferation and induced apoptosis of CCRF-CEM and CEM/C1 (P<0.05), and CCRF-CEM cell cycle were arrested at S phase, and CEM/C1 cells were arrested at G₀/G₁ phase. Western blot and qPCR results show that FA-2-b-β inhibited ABCB1、ABCG2、CTNNB、MYC and BCL-2 expression, but upregulated Bax expression. In addition, FA-2-b-β reversed the resistance characteristics of CEM/C1 drug-resistance cells, which decreased mitochondrial membrane potential, and significantly increased the intracellular rhodamine accumulation, and weakening of the expression of the membrane surface protein MDR1. With the Wnt/β-catenin inhibitor (ICG001), the process was further intensified. CONCLUSION Agaricus Blazei Extract FA-2-b-β inhibits cell proliferation, promotes apoptosis, regulates the cell cycle, reduces mitochondrial energy supply, and down-regulate MDR1 expression to reverse the resistance of CEM/C1, which all suggest it is through regulating the Wnt signaling pathway in T-ALL.
Humans ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; Wnt Signaling Pathway ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism* ; Apoptosis ; Drug Resistance, Multiple ; Membrane Proteins ; Cell Line, Tumor ; Cell Proliferation

OBJECTIVE: To detect the differential expressions of miR-451, ABCB1 and ABCC2 in drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, and explore the regulatory relationship between miR-451 and the expressions of ABCB1 and ABCC2 , and the mechanism of miR-451 involved in drug resistance in leukemia. METHODS: CCK-8 assay was used to detect the drug resistance of K562/A02 and K562 cells. Quantitative Real-time PCR (qRT-PCR) was used to verify the differential expressions of miR-451 in K562 and K562/A02 cells. MiR-451 mimic and negative control (miR-NC), miR-451 inhibitor and negative control (miR-inNC) were transfected into K562 and K562/A02 cells respectively, then qRT-PCR and Western blot were used to detect the expression levels of mRNA and protein of ABCB1 and ABCC2 in K562 and K562/A02 cells and the transfected groups. RESULTS: The drug resistance of K562/A02 cells to adriamycin was 177 times higher than that of its parent cell line K562. Compared with K562 cells, the expression of miR-451 in K562/A02 cells was significantly higher (P <0.001), and the mRNA and protein expression levels of ABCB1 and ABCC2 in K562/A02 cells were significantly higher than those in K562 cells (P <0.001). After transfected with miR-451 inhibitor, the expression of miR-451 was significantly down-regulated in K562/A02 cells (P <0.001), the sensitivity to chemotherapy drugs was significantly enhanced (P <0.05), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly decreased (P <0.01). After transfected with miR-451 mimic, the expression of miR-451 was significantly upregulated in K562 cells (P <0.001), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly increased (P <0.01). CONCLUSION There are significant differences in the expressions of miR-451, ABCB1 and ABCC2 between the drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, which suggests that miR-451 may affect the drug resistance of leukemia cells by regulating the expression of ABCB1 and ABCC2.
Humans ; K562 Cells ; Drug Resistance, Neoplasm/genetics* ; Drug Resistance, Multiple/genetics* ; Doxorubicin/pharmacology* ; MicroRNAs/genetics* ; Leukemia/genetics* ; RNA, Messenger

Objective: To analyze the epidemic characteristics and drug resistance of pulmonary tuberculosis among the floating population in Beijing and to provide a scientific basis for formulating strategies for the prevention and control of tuberculosis among the floating population. Methods: Data of tuberculosis patients who were positive for Mycobacterium tuberculosis culture was collected from 16 districts and one municipal institution of tuberculosis control and prevention in Beijing in 2019. The strain samples were tested for drug sensitivity by the proportional method. According to household registration location, patients were divided into the floating population and Beijing registration. SPSS 19.0 software analyzed tuberculosis patients' epidemic characteristics and drug resistance in the floating population. Results: In 2019, there were 1 171 culture-positive tuberculosis patients in Beijing, among the floating population, 593 (50.64%) patients were identified, with a male-to-female sex ratio of 2.2∶1 (409∶184). Compared to patients under household registration as Beijing residents, a higher proportion of young adults aged 20-39 years (65.09%,386/593) were noticed, with 55.65% (330/593) reported from the urban areas and 96.80% (574/593) were reported the first time. The differences were statistically significant (all P<0.05). After completing the drug sensitivity test, 37 cases were with multiple drug-resistant tuberculosis, accounting for 6.24% (37/593). The rates of isoniazid resistance (42.11%,8/19) and multidrug resistance (21.05%,4/19) in floating population patients after retreatment were significantly higher than those in newly treated patients (11.67%, 67/574 and 5.75%, 33/574), and the differences were statistically significant (all P<0.05). Conclusions: Most patients with tuberculosis in the floating population in Beijing in 2019 were young males aged 20-39 years. The reporting areas were urban areas and the newly treated patients mainly. The patients with tuberculosis in the re-treated floating population were more likely to suffer from multidrug and drug resistance, which should be taken as the key population for prevention and control.
Young Adult ; Humans ; Female ; Male ; Beijing/epidemiology* ; Tuberculosis ; Tuberculosis, Pulmonary/epidemiology* ; Tuberculosis, Multidrug-Resistant/epidemiology* ; Drug Resistance

Objective: To evaluate the clinical value of the MeltPro MTB assays in the diagnosis of drug-resistant tuberculosis. Methods: A cross-sectional study design was used to retrospectively collect all 4 551 patients with confirmed tuberculosis between January 2018 and December 2019 at Beijing Chest Hospital, Capital Medical University. Phenotypic drug sensitivity test and GeneXpert MTB/RIF (hereafter referred to as "Xpert") assay were used as gold standards to analyze the accuracy of the probe melting curve method. The clinical value of this technique was also evaluated as a complementary method to conventional assays of drug resistance to increase the detective rate of drug-resistant tuberculosis. Results: By taking the phenotypic drug susceptibility test as the gold standard, the sensitivity of the MeltPro MTB assays to detect resistance to rifampicin, isoniazid, ethambutol and fluoroquinolone was 14/15, 95.7%(22/23), 2/4 and 8/9,respectively; and the specificity was 92.0%(115/125), 93.2%(109/117), 90.4%(123/136) and 93.9%(123/131),respectively; the overall concordance rate was 92.1%(95%CI:89.6%-94.1%),and the Kappa value of the consistency test was 0.63(95%CI:0.55-0.72).By taking the Xpert test results as the reference, the sensitivity of this technology to the detection of rifampicin resistance was 93.6%(44/47), the specificity was100%(310/310), the concordance rate was 99.2%(95%CI:97.6%-99.7%), and the Kappa value of the consistency test was 0.96(95%CI:0.93-0.99). The MeltPro MTB assays had been used in 4 551 confirmed patients; the proportion of patients who obtained effective drug resistance results increased from 83.3% to 87.8%(P<0.01); and detection rate of rifampicin, isoniazid, ethambutol, fluoroquinolone resistance, multidrug and pre-extensive drug resistance cases were increased by 3.2%, 14.7%, 22.2%, 13.7%, 11.2% and 12.5%, respectively. Conclusion: The MeltPro MTB assays show satisfactory accuracy in the diagnosis of drug-resistant tuberculosis. This molecular pathological test is an effective complementary method in improving test positivity of drug-resistant tuberculosis.
Humans ; Rifampin/therapeutic use* ; Antibiotics, Antitubercular/therapeutic use* ; Mycobacterium tuberculosis ; Ethambutol/pharmacology* ; Isoniazid/pharmacology* ; Paraffin Embedding ; Retrospective Studies ; Cross-Sectional Studies ; Drug Resistance, Bacterial ; Sensitivity and Specificity ; Tuberculosis, Multidrug-Resistant/drug therapy*

Multiple myeloma (MM) is a common plasma cell malignancy, accounting for the second largest hematological malignancy. Proteasome inhibitors represented by bortezomib (BTZ) have been the main treatment for patients with newly diagnosed and relapsed or refractory myeloma in nearly two decades. Although BTZ has improved the prognosis of MM patients, MM remains incurable in most patients, mainly because MM cells become resistant to BTZ. This review is to better understand the mechanism of MM resistance to BTZ and explore possible new therapeutic strategies.
Humans ; Bortezomib/therapeutic use* ; Multiple Myeloma/pathology* ; Proteasome Inhibitors/pharmacology* ; Prognosis ; Plasma Cells/pathology* ; Drug Resistance, Neoplasm ; Antineoplastic Agents/pharmacology* ; Cell Line, Tumor