Establishment of patient-derived organoids for guiding personalized therapies in breast cancer patients

Breast cancer has become the most commonly diagnosed cancer. The intra- and interpatient heterogeneity induced a considerable variation in treatment efficacy. There is an urgent requirement for preclinical models to anticipate the effectiveness of individualized drug responses. Patient-derived organoids (PDOs) can accurately recapitulate the architecture and biological characteristics of the origin tumor, making them a promising model that can overtake many limitations of cell lines and PDXs. However, it is still unclear whether PDOs-based drug testing can benefit breast cancer patients, particularly those with tumor recurrence or treatment resistance. Fresh tumor samples were surgically resected for organoid culture. Primary tumor samples and PDOs were subsequently subjected to H&E staining, immunohistochemical (IHC) analysis, and whole-exome sequencing (WES) to make comparisons. Drug sensitivity tests were performed to evaluate the feasibility of this model for predicting patient drug response in clinical practice. We established 75 patient-derived breast cancer organoid models. The results of H&E staining, IHC, and WES revealed that PDOs inherited the histologic and genetic characteristics of their parental tumor tissues. The PDOs successfully predicted the patient's drug response, and most cases exhibited consistency between PDOs' drug susceptibility test results and the clinical response of the matched patient. We conclude that the breast cancer organoids platform can be a potential preclinical tool used for the selection of effective drugs and guided personalized therapies for patients with advanced breast cancer.

Nocardiosis and other common diseases of cultured golden pompano (Trachinotus blochii) in Taiwan

Golden pompano (Trachinotus blochii) is a carnivorous teleost cultured in the Asia-Pacific region. Fish culture in high densities and numbers results in disease outbreaks, causing huge economic losses. Here, we collected cultured golden pompanos from 2021 to 2022 and identified the pathogens isolated from the diseased fish. Out of a total of 64 clinical cases observed in both sea cages and fish ponds, it was found that Nocardia seriolae was the predominant pathogen (26%), followed by Lactococcus garvieae (13%). Trichodina spp. was the most prevalent parasite in sea cages and earthen ponds (21%), while Neobenedenia spp. was the primary parasitic pathogen (16%) in sea cages. Given these findings, further investigations were conducted, including antibiotic susceptibility and pathogenicity tests specific to N. seriolae in golden pompanos. Antibiotic susceptibility tests of N. seriolae revealed that all strains were susceptible to doxycycline, oxytetracycline, florfenicol and erythromycin but resistant to amoxicillin and ampicillin. Additionally, a pathogenicity assessment was carried out by administering an intraperitoneal injection of 0.1 mL containing 107  CFU of N. seriolae per fish. The mortality rates observed varied between 40% and 90%, with the P2 strain exhibiting the highest level of virulence, resulting in a cumulative mortality of 90%. Therefore, disease outbreaks in fish can be minimized by developing effective treatments and prevention methods.

Effective Treatment for Recurrent Ovarian Cancer Guided by Drug Sensitivity from Ascites-Derived Organoid: A Case Report

So far, ovarian cancer has still been the most lethal gynecological malignancy. The chemotherapy and targeted medication are the mainstay for the recurrent ovarian cancer treatment. About 70% of the advanced-stage cases will relapse. Ascites-derived organoid is a pre-clinical model for the precise prediction of the therapeutic effectiveness for the ovarian cancer: it can be used to assess the drug sensitivity, to guide individualized precise treatment, and to improve advanced stage as well as recurrent ovarian cancer patient' survival and prognosis. Until now, there has been no report concerning the establishment of the organoid out of the patient's ascites and the concurrent usage of drug sensitivity test to guide the individualized precise treatment for the ovarian cancer. Here, we report a case of recurrent ovarian cancer of a 59-year-old female patient whose CA125 at its peak increased to 4523.4 U/mL. Then, patient's own ovarian cancer organoid was constructed from the ascites by the abdominocentesis; concurrently, medication sensitivity test was performed on the organoid to guide individualized precise treatment. After the treatment, CA125 decreased to 33.7 U/mL, and the patient's condition relieved effectively. This is the first published case report using ascites-derived organoid and the drug sensitivity test thereof to guide the precise treatment of recurrent ovarian cancer.

Using patient-derived organoids to predict locally advanced or metastatic lung cancer tumor response: A real-world study

Predicting the clinical response to chemotherapeutic or targeted treatment in patients with locally advanced or metastatic lung cancer requires an accurate and affordable tool. Tumor organoids are a potential approach in precision medicine for predicting the clinical response to treatment. However, their clinical application in lung cancer has rarely been reported because of the difficulty in generating pure tumor organoids. In this study, we have generated 214 cancer organoids from 107 patients, of which 212 are lung cancer organoids (LCOs), primarily derived from malignant serous effusions. LCO-based drug sensitivity tests (LCO-DSTs) for chemotherapy and targeted therapy have been performed in a real-world study to predict the clinical response to the respective treatment. LCO-DSTs accurately predict the clinical response to treatment in this cohort of patients with advanced lung cancer. In conclusion, LCO-DST is a promising precision medicine tool in treating of advanced lung cancer.

Organoids From Mucinous Appendiceal Adenocarcinomas as High-Fidelity Models for Individual Therapy

Background

Mucinous appendiceal adenocarcinoma (MAA) is a rare, heterogeneous disease. Patients with unrespectable mucinous appendiceal adenocarcinoma presenting with peritoneal spread are treated by intraperitoneal chemotherapy, hyperthermic intraperitoneal chemotherapy, systemic chemotherapy, or targeted therapy. However, there are no guidelines for efficacious drugs against mucinous appendiceal adenocarcinoma. Therefore, relevant high-fidelity models should be investigated to identify effective drugs for individual therapy.

Methods

Surgical tumor specimens were obtained from a mucinous appendiceal adenocarcinoma patient. The tissue was digested and organoid culture was established. H&E and immunohistochemistry staining as well as DNA sequencing was performed on tissue and organoid. The pathological characteristics and gene mutations of the organoid were compared to those of the original tumor. Drug sensitivity tests were performed on organoid and the patient clinical responds to chemotherapy and targeted therapy was compared.

Results

Organoids were successfully established and stably passaged. Pathological characteristics of organoids including H&E staining and expression of protein markers (CK20, CDX-2, STAB2, CD7, PAX8) were consistent to those of the original tumor. Moreover, the organoids carried the same gene mutations as the primary tumor. Sensitivity of the organoids to chemotherapeutic drugs and tyrosine kinase inhibitors included: 5-FU (IC₅₀ 43.95 μM), Oxaliplatin (IC₅₀ 23.49 μM), SN38 (IC₅₀ 1.02 μM), Apatinib (IC₅₀ 0.10 μM), Dasatinib (IC₅₀ 2.27 μM), Docetaxel (IC₅₀ 5.26 μM), Regorafenib (IC₅₀ 18.90 μM), and Everolimus (IC₅₀ 9.20 μM). The sensitivities of organoid to these drugs were comparable to those of the patient's clinical responses.

Conclusion

The mucinous appendiceal adenocarcinoma organoid model which retained the characteristics of the primary tumor was successfully established. Combined organoid-based drug screening and high throughput sequencing provided a promising way for mucinous appendiceal adenocarcinoma treatment.

First Report of Bacteremia Caused by Clostridium cadaveris in China

Background

Bacteremia caused by C. cadaveris is an extremely rare infection that accounts for 0.5–2% of all positive blood cultures. C. cadaveris is an opportunistic agent that is highly lethal in immunocompromised or epithelial barrier disruption hosts.

Case Presentation

A 74-year-old woman was admitted to our hospital with a high fever. The patient was diagnosed with an abdominal infection after a bowel invasion and recurrence of an ovarian tumor after surgery. Blood sample culturing yielded transparent, smooth, moist, slightly raised colonies without a hemolytic ring. C. cadaveris was identified by gram staining and MALDI-TOF MS. 16S rRNA gene sequencing confirmed a sequence homologous to C. cadaveris in the GenBank database. Drug susceptibility testing showed that C. cadaveris was sensitive to cefoxitin, clindamycin, imipenem, meropenem, metronidazole, and vancomycin. After treatment, the patient’s body temperature was normal and she was discharged from the hospital.

Conclusion

This is the first case report of bacteremia caused by C. cadaveris in China and also the first report of identifying C. cadaveris in clinical specimens by MALDI-TOF MS. This case study could increase the awareness of these infections in China.

Establishment and characterization of organoids from a patient with adenomyoepithelioma of the breast

Adenomyoepithelioma (AME) of the breast is a rare tumor that is composed of proliferating epithelial and myoepithelial cells. The pathogenesis of AME remains unclear, and no breast cancer cells have been identified in such tumor tissues. In this study, we established patient-derived breast cancer organoids from the surgical tumor samples of an elderly Chinese woman with an AME of the breast. Our findings confirmed the successful establishment of organoids from an AME of the breast of this patient. A short tandem repeat analysis revealed that the DNA signature of the AME of the breast organoids matched the DNA signature of the original tumor specimen. Moreover, diameter assay confirmed that the organoids from the breast AME showed sensitivity to paclitaxel and doxorubicin treatments, which was similar to, but lesser than that of primary culture cells. In conclusion, we established an efficient 3-dimensional breast cancer organoid culture platform from an AME of the breast. This platform can be effectively used for exploring clinicopathological and genomic characteristics of AME of the breast to identify possible treatments and increase awareness about this disease entity.

Case Report: MDM4 Amplified in a Thymoma Patient With Autoimmune Enteropathy and Myocarditis

INTRODUCTION

Thymoma is a type of mediastinal malignant tumors which always associated with autoimmune diseases. Although surgery is the predominant treatment method for thymoma, the pathogenesis of thymoma and thymoma-associated autoimmune diseases is still unknown. However, the case study here provided a possible pathogenesis and treatment to cure the thymoma with autoimmune enteropathy and myocarditis.

CASE PRESENTATION

A thymoma case with autoimmune enteropathy and myocarditis undergoing surgery was reported. The symptoms and laboratory results of the patient had dramatically fluctuated after tumor resection and gradually alleviated. The whole exome sequencing found MDM4 amplified in tumor cells. Immunohistochemistry indicated that thymoma cells were positive for MDM4. The result of drug sensitivity tests showed thymoma cells were highly sensitive to Nutlin-3a.

CONCLUSION

MDM4 could play an important role in the pathogenesis of this thymoma case with autoimmune enteropathy and myocarditis. This discovery may provide a novel idea of pathogenesis and treatment for thymoma and autoimmune diseases.

Longitudinal monitoring of multidrug resistance in Escherichia coli on broiler chicken fattening farms in Shandong, China

The extensive use of antibiotics has, in recent years, caused antimicrobial resistance and multidrug resistance in Escherichia coli to gradually develop into a worldwide problem. These resistant E. coli could be transmitted to humans through animal products and animal feces in the environment, thereby creating a problem for bacterial treatment for humans and animals and resulting in a public health issue. Monitoring the resistance of E. coli throughout the broiler fattening period is therefore of great significance for both the poultry industry and public health. In this longitudinal study, samples were taken from 6 conventional broiler fattening farms in Shandong Province, China, at 3 different times within 1 fattening period. The overall isolation rate of E. coli was 53.04% (375/707). Antibiotic resistance was very common in the E. coli isolated from these farms, and differed for different antibiotics, with ampicillin having the highest rate (92.86%) and cefoxitin the lowest (10.12%). Multidrug resistance was as high as 91.07%. More importantly, both the resistance rate of E. coli to the different drugs and the detection rate of drug resistance genes increased over time. The mobile colistin resistance (mcr-1) gene was detected in 24.40% of the strains, and these strains often carried other drug resistance genes, such as those conferring aminoglycoside, β-lactamase, tetracycline, and sulfonamide resistance. Antimicrobial resistance and drug resistance genes in E. coli were least common in the early fattening stage. The individual detection rates of sul1, sul3, aacC4, aphA3, and mcr-1 were significantly lower (P < 0.05) for the early fattening stage than for the middle and late stages. The rational use of antibiotics, in conjunction with the improvement of the breeding environment during the entire broiler fattening cycle, will be helpful in the development of the poultry industry and the protection of public health.

Establishment of PDX-derived salivary adenoid cystic carcinoma cell lines using organoid culture method

To generate a reliable preclinical model system exhibiting the molecular features of salivary adenoid cystic carcinoma (ACC) whose biology is still unclear due to the paucity of stable cell cultures. To develop new in vitro and in vivo models of ACC, the techniques of organoid culture and patient-derived tumor xenograft (PDX), which have attracted attention in other malignancies in recent years, were applied. Tumor specimens from surgically resected salivary ACC were proceeded for the preparation of PDX and organoid culture. The orthotopic transplantation of patient-derived or PDX-derived organoids was demonstrated into submandibular glands of NSG mice and those histology was evaluated. PDX-derived organoid cells were evaluated for the presence of MYB-mediated fusion genes and proceeded for in vitro drug sensitivity assay. Human ACC-derived organoids were successfully generated in three-dimensional culture and confirmed the ability of these cells to form tumors by orthotopic injection. Short-term organoid cell cultures from two individual ACC PDX tumors were also established that maintain the characteristic MYBL1 translocation and histological features of the original parent and PDX tumors. Finally, the establishment of drug sensitivity tests on these short-term cultured cells was confirmed using three different agents. This is the first to report an approach for the generation of human ACC-derived organoids as in vitro and in vivo cancer models, providing insights into understanding of the ACC biology and creating personalized therapy design for patients with ACC.

In Vitro Antibacterial Experiment of Fuzheng Jiedu Huayu Decoction Against Multidrug-Resistant Pseudomonas aeruginosa

Objective

Drawing a growth curve of multidrug-resistant Pseudomonas aeruginosa (MDR-PA) provides a foundation for susceptibility testing. By observing in vitro antibacterial activity and ultrastructure cthanges on MDR-PA of the effective components in the drug-containing serum of rats after the administration of Fuzheng Jiedu Huayu decoction (FJHD), we evaluated the inhibition and direct destruction effect of bacteria by TCM alone or combined with antibiotics.

Methods

The absorbance values of MDR-PA were determined at different detection time points, and a growth curve was drawn. After gavage with FJHD, drug-containing serum was collected from the rats. Using Imipenem/cilastatin sodium as the positive drug control, the in vitro antibacterial potency of FJHD and its drug-containing serum alone or in combination with antibiotics against MDR-PA was observed. The ultrastructural changes of MDR-PA treated by FJHD combined with antibiotics were observed by transmission electron microscopy.

Results

Growth of the experimental strain manifested a lag phase in the first 1-4 h, an exponential growth phase at 5-20 h, and a plateau phase after 20 h. The best detection time during the susceptibility test was 16-20 h. The minimum inhibitory concentration (MIC) value of the FJHD extract group was 0.2 g/mL. The MIC value of the pure Imipenem/cilastatin sodium group was 16 μg/mL. The MIC values of Imipenem/cilastatin sodium + blank serum, 0.5-, 1-, and 2-fold drug-containing serum groups were all 16 μg/mL. The MIC values of Imipenem/cilastatin sodium + 4- and 8-fold drug-containing serum groups were both 8 μg/mL. By observation under a transmission electron microscope, Imipenem/cilastatin sodium + 0.5-, 1-, and 2-fold drug-containing serum groups showed bacterial structural damage. The degree of bacterial destruction was more obvious and the quantity of damaged bacteria was increased in the Imipenem/cilastatin sodium + 4- and 8-fold drug-containing serum groups.

Conclusion

Drawing the growth curve of the experimental strain had high application value for ensuring the accuracy of the drug sensitivity test results. TCM combined with antibiotics could enhance the antibacterial and direct destruction effect of bacteria in vitro, thereby inhibiting bacterial resistance to a certain extent.

Prevalence and characteristics of multidrug-resistant mcr-1-positive Escherichia coli isolates from broiler chickens in Tai'an, China

Colibacillosis, caused by Escherichia coli, is one of the most common bacterial diseases of chickens. The high incidence and considerable economic losses associated with colibacillosis make it a significant concern worldwide. In recent years, the efficacy of colistin has been severely impacted by the emergence of plasmid-mediated colistin resistance genes, especially mcr-1. Therefore, monitoring of antibiotic resistance, particularly colistin resistance, amongst E. coli strains is vitally important to the future growth and sustainability of the poultry industry. In this study, a total of 130 E. coli strains were isolated from the livers of chickens displaying symptoms of colibacillosis in Tai'an, China. Isolates were screened for their susceptibility to various antibiotics and for the presence of mobile colistin resistance genes and other antibiotic resistance genes. Overall, 75 (57.7%) isolates showed resistance to colistin and were positive for mcr-1. The mobile colistin resistance genes, mcr-2, -3, and -4, were not detected in this study. Of the 75 mcr-1-positive isolates, all (100%) also carried tetracycline resistance genes, 71 (94.7%) also contained genes associated with β-lactam resistance, 59 (78.7%) contained aminoglycoside resistance genes, and 57 (76%) contained sulfonamide resistance genes. This high prevalence of multidrug resistance among mcr-1-positive E. coli isolates, including the production of extended-spectrum β-lactamases, is highly concerning. The surveillance findings presented here will be conducive to our understanding of the prevalence and characteristics of multidrug-resistance in E. coli in the Tai'an area and will provide a better scientific basis for the clinical treatment of colibacillosis in chickens.

[Clinical features and drug resistance in children with Salmonella infection]

OBJECTIVE

To study the clinical features and drug resistance in children with Salmonella infection.

METHODS

A total of 163 children with positive fecal cultures for Salmonella who were hospitalized between 2013 and 2017 were enrolled. A retrospective analysis was performed for their data on clinical features, distribution of Salmonella serotypes, and drug sensitivity test results.

RESULTS

Among the 163 children with Salmonella infection, 79 (48.5%) were aged ≤1 year. Main clinical manifestations included fever and diarrhea. Of all the children, 121 (74.2%) reached a body temperature of above 39°C, 52 (31.9%) had diarrhea more than 10 times a day, and 56 (34.4%) had respiratory infection. Salmonella infection often occurred in summer and autumn. Of all the children, 131 (80.4%) had the infection in May to October. Salmonella typhimurium was observed in 100 children (61.3%) and Salmonella enteritidis was observed 15 children (9.2%). All serotypes of Salmonella had a drug resistance rate of >20% to cefotaxime, as well as high sensitivities to β-lactamase inhibitors (amoxicillin/clavulanic acid and piperacillin/tazobactam). There were no strains resistant to carbapenems including imipenem.

CONCLUSIONS

Infants aged ≤1 year are susceptible to Salmonella infection in summer and autumn, and the most common serotype is Salmonella typhimurium. Main clinical manifestations are fever and diarrhea in children with Salmonella infection, and most children also have respiratory infection. Salmonella has an increased rate of drug resistance to third-generation cephalosporins. In clinical treatment, antimicrobial drugs should be used according to the results of drug sensitivity test.

Pretreatment evaluation of fluorescence resonance energy transfer-based drug sensitivity test for patients with chronic myelogenous leukemia treated with dasatinib

Tyrosine kinase inhibitors (TKI) are used for primary therapy in patients with newly diagnosed CML. However, a reliable method for optimal selection of a TKI from the viewpoint of drug sensitivity of CML cells has not been established. We have developed a FRET-based drug sensitivity test in which a CrkL-derived fluorescent biosensor efficiently quantifies the kinase activity of BCR-ABL of living cells and sensitively evaluates the inhibitory activity of a TKI against BCR-ABL. Here, we validated the utility of the FRET-based drug sensitivity test carried out at diagnosis for predicting the molecular efficacy. Sixty-two patients with newly diagnosed chronic phase CML were enrolled in this study and treated with dasatinib. Bone marrow cells at diagnosis were subjected to FRET analysis. The ΔFRET value was calculated by subtraction of FRET efficiency in the presence of dasatinib from that in the absence of dasatinib. Treatment response was evaluated every 3 months by the BCR-ABL1 International Scale. Based on the ΔFRET value and molecular response, a threshold of the ΔFRET value in the top 10% of FRET efficiency was set to 0.31. Patients with ΔFRET value ≥0.31 had significantly superior molecular responses (MMR at 6 and 9 months and both MR4 and MR4.5 at 6, 9, and 12 months) compared with the responses in patients with ΔFRET value <0.31. These results suggest that the FRET-based drug sensitivity test at diagnosis can predict early and deep molecular responses. This study is registered with UMIN Clinical Trials Registry (UMIN000006358).

Characterization of ascites-derived tumor cells from an endometrial cancer patient

Improved treatment outcomes for the endometrial cancer patient requires precision methods to investigate the biology of this disease and clinically relevant models to test treatment drugs. Hence, we applied a personalized platform to investigate whether in vitro and in vivo models could accurately predict effective treatment regimens. We successfully expanded ascites‐derived tumor cells from an endometrial cancer patient with malignant ascites using ascites collected prior to chemotherapy treatment. Hematoxylin–eosin and immunohistochemistry staining of ascites‐derived tumor cells confirmed the source of endometrial cancer cells. Ascites‐derived tumor cells were sensitive to cisplatin and doxorubicin single‐agent treatments in CCK‐8 assay and 3‐D culture, a condition that more closely mimics the in vivo environment. We further showed that ascites‐derived tumor cells from this patient could form tumors in NOD/SCID mice with preserved morphological characteristics. A remarkable concordance between the clinical response of cisplatin and the results of in vitro and in vivo drug tests reflected the reliability of our personalized approach in this case. Together, our results indicated that an effective platform for ex vivo and in vivo culture of ascites‐derived tumor cells from our endometrial cancer patient could be applied to identify treatment options, and may be commonly used in treating cancer patients with malignant ascites in the future.

Distribution of drug-resistant bacteria and rational use of clinical antimicrobial agents

Open wound may lead to infection in patients. Due to overuse of medication, certain bacteria have become resistant to drugs currently available. The aim of the present study was to provide a guide to ameliorate the appropriate and rational use of clinical antimicrobial agents by analyzing the distribution of drug-resistant pathogenic bacteria in patients. Between October 2013 and January 2015, 126 patients were selected at the Department of Orthopedics. Wound secretion samples were collected, and the pathogen bacteria isolated and identified. Identification was performed using an automated identification instrument and the Kirby-Bauer antibiotic method was used to evaluate the bacterial resistance. Of the 126 patients, 118 patients were infected (infection rate, 93.65%). Additionally, 47 strains of gram-positive pathogenic bacteria (39.83%) and 71 strains of pathogenic-gram negative bacteria (60.17%) were identified. The bacteria were most likely to be resistant to penicillin while sensitive to vancomycin and imipenem. Some bacteria were resistant to several antibacterial agents. The results showed that existing risk factors at the Department of Orthopedics were complex and any non-standard procedures were able to cause bacterial infection. There were obvious dissimilarities among infectious bacteria with regard to their sensitivity to various antibacterial agents. Manipulation techniques during the treatment process were performed in a sterile manner and the use of antibacterial agents was required to be strictly in accordance with the results of drug sensitivity tests to provide effective etiologic information and a treatment plan for clinical trials and to reduce the risk of infection by multi-resistant bacteria.

Clinical analysis of pulmonary infection in hemodialysis patients

The present study aimed to investigate the pathogen distribution and drug resistance of lung infections in hemodialysis to guide clinical empirical pharmacy. The clinical data of 116 hemodialysis patients with pulmonary infection were analyzed. The majority of the 82 pathogens isolated from the sputa of patients were Gram-negative bacteria (accounting for 71.95%). The results of the drug sensitivity test suggested that Gram-negative bacilli had low resistance rates to piperacillin and tazobactam, imipenem and amikacin, while Gram-positive cocci had a low resistance rate to vancomycin. All resistance rates of the pathogens to other common antimicrobials were >50%. The pathogens resulting in lung infections in hemodialysis patients were mainly Gram-negative bacteria and were significantly resistant to various antibacterials. Results of the this study demonstrate that pathological examination should be performed as early as possible and effective antimicrobial agents should be chosen according to drug sensitivity test results.

Patterns of antituberculous drug resistance in Eastern Saudi Arabia: a 7-year surveillance study from 1/2003 to 6/2010

OBJECTIVE

To examine the patterns of antituberculous drug resistance of Mycobacterium tuberculosis in patients with pulmonary and extra-pulmonary tuberculosis in the Eastern province of the Kingdom of Saudi Arabia.

METHODS

This is a retrospective study of antibiotic susceptibility of 1681 non-repetitive M. tuberculosis isolates from 1/2003 to 6/2010.

RESULTS

Of the total patients, 41% (n=687) were Saudis and 59% (n=994) were non-Saudis. The pulmonary and extra-pulmonary specimens constituted 68% (n=1148) and 32% (n=533), respectively. The incidence of resistance was 15.5% to one or more of anti-tuberculosis drugs. The resistance rates to first-line drugs were as follows: streptomycin (10.4%), INH (9.8%), rifampicin (1.5%) and ethambutol (1.0%). Multi-drug resistant tuberculosis was present in 1.4% (n=24) of the sample.

CONCLUSION

INH resistance in this study was relatively high, whereas the rate of MDR-TB was low. A rate of MDR-TB observed in this study was 1.4%. Thus, an empiric four-drug therapy is required to treat patients with tuberculosis in this area of Saudi Arabia.