Identification of Mycobacterium tuberculosis Resistance to Common Antibiotics: An Overview of Current Methods and Techniques.

Multidrug-resistant tuberculosis (MDR-TB) is an essential cause of tuberculosis treatment failure and death of tuberculosis patients. The rapid and reliable profiling of Mycobacterium tuberculosis (MTB) drug resistance in the early stage is a critical research area for public health. Then, most traditional approaches for detecting MTB are time-consuming and costly, leading to the inappropriate therapeutic schedule resting on the ambiguous information of MTB drug resistance, increasing patient economic burden, morbidity, and mortality. Therefore, novel diagnosis methods are frequently required to meet the emerging challenges of MTB drug resistance distinguish. Considering the difficulty in treating MDR-TB, it is urgently required for the development of rapid and accurate methods in the identification of drug resistance profiles of MTB in clinical diagnosis. This review discussed recent advances in MTB drug resistance detection, focusing on developing emerging approaches and their applications in tangled clinical situations. In particular, a brief overview of antibiotic resistance to MTB was present, referred to as intrinsic bacterial resistance, consisting of cell wall barriers and efflux pumping action and acquired resistance caused by genetic mutations. Then, different drug susceptibility test (DST) methods were described, including phenotype DST, genotype DST and novel DST methods. The phenotype DST includes nitrate reductase assay, RocheTM solid ratio method, and liquid culture method and genotype DST includes fluorescent PCR, GeneXpert, PCR reverse dot hybridization, ddPCR, next-generation sequencing and gene chips. Then, novel DST methods were described, including metabolism testing, cell-free DNA probe, CRISPR assay, and spectral analysis technique. The limitations, challenges, and perspectives of different techniques for drug resistance are also discussed. These methods significantly improve the detection sensitivity and accuracy of multidrug-resistant tuberculosis (MRT) and can effectively curb the incidence of drug-resistant tuberculosis and accelerate the process of tuberculosis eradication.

Quantitative Polymerase Chain Reaction (qPCR)-Based Rapid Diagnosis of Helicobacter pylori Infection and Antibiotic Resistance.

Helicobacter pylori is a major human pathogen that infects approximately half of the global population and is becoming a serious health threat due to its increasing antibiotic resistance. It is the causative agent of chronic active gastritis, peptic ulcer disease, and gastric cancer and has been classified as a Group I Carcinogen by the International Agency for Research on Cancer. Therefore, the rapid and accurate diagnosis of H. pylori and the determination of its antibiotic resistance are important for the efficient eradication of this bacterial pathogen. Currently, H. pylori diagnosis methods mainly include the urea breath test (UBT), the antigen test, the serum antibody test, gastroscopy, the rapid urease test (RUT), and bacterial culture. Among them, the first three detection methods are noninvasive, meaning they are easy tests to conduct. However, bacteria cannot be retrieved through these techniques; thus, drug resistance testing cannot be performed. The last three are invasive examinations, but they are costly, require high skills, and have the potential to cause damage to patients. Therefore, a noninvasive, rapid, and simultaneous method for H. pylori detection and drug resistance testing is very important for efficiently eradicating H. pylori in clinical practice. This protocol aims to present a specific procedure involving the string test in combination with quantitative polymerase chain reaction (qPCR) for the rapid detection of H. pylori infection and antibiotic resistance. Unlike bacterial cultures, this method allows for easy, rapid, noninvasive diagnosis of H. pylori infection status and drug resistance. Specifically, we used qPCR to detect rea for H. pylori infection and mutations in the 23S rRNA and gyrA genes, which encode resistance against clarithromycin and levofloxacin, respectively. Compared to routinely used culturing techniques, this protocol provides a noninvasive, low-cost, and time-saving technique to detect H. pylori infection and determine its antibiotic resistance using qPCR.

Rapid discrimination of Shigella spp. and Escherichia coli via label-free surface enhanced Raman spectroscopy coupled with machine learning algorithms.

Shigella and enterotoxigenic Escherichia coli (ETEC) are major bacterial pathogens of diarrheal disease that is the second leading cause of childhood mortality globally. Currently, it is well known that Shigella spp., and E. coli are very closely related with many common characteristics. Evolutionarily speaking, Shigella spp., are positioned within the phylogenetic tree of E. coli. Therefore, discrimination of Shigella spp., from E. coli is very difficult. Many methods have been developed with the aim of differentiating the two species, which include but not limited to biochemical tests, nucleic acids amplification, and mass spectrometry, etc. However, these methods suffer from high false positive rates and complicated operation procedures, which requires the development of novel methods for accurate and rapid identification of Shigella spp., and E. coli. As a low-cost and non-invasive method, surface enhanced Raman spectroscopy (SERS) is currently under intensive study for its diagnostic potential in bacterial pathogens, which is worthy of further investigation for its application in bacterial discrimination. In this study, we focused on clinically isolated E. coli strains and Shigella species (spp.), that is, S. dysenteriae, S. boydii, S. flexneri, and S. sonnei, based on which SERS spectra were generated and characteristic peaks for Shigella spp., and E. coli were identified, revealing unique molecular components in the two bacterial groups. Further comparative analysis of machine learning algorithms showed that, the Convolutional Neural Network (CNN) achieved the best performance and robustness in bacterial discrimination capacity when compared with Random Forest (RF) and Support Vector Machine (SVM) algorithms. Taken together, this study confirmed that SERS paired with machine learning could achieve high accuracy in discriminating Shigella spp., from E. coli, which facilitated its application potential for diarrheal prevention and control in clinical settings. Graphical abstract.

Prevalence of healthcare-associated infections and antimicrobial use in China: Results from the 2018 point prevalence survey in 189 hospitals in Guangdong Province.

BACKGROUND: Limited data on healthcare-associated infections (HAIs) are available from the developing world, thus a point prevalence survey was conducted to determine the prevalence of HAIs and antimicrobial use in Guangdong Province, China. METHODS: A standardized methodology for point prevalence surveys on HAIs and antimicrobial use has been developed by the Chinese Nosocomial Infection Control and Quality Improvement Center. The prevalence of HAIs, antimicrobial use, and baseline hospital-level variables were collected in 189 hospitals from June 2017 to May 2018. RESULTS: Of 5 868 147 patients, 72 976 had one or more HAIs (1.24%), with 82 700 distinct HAIs. The prevalence rates of device-associated infections, including ventilator-associated pneumonia, catheter-associated urinary tract infection, and central line-associated bloodstream infection were 7.92, 2.06, and 0.63 per 1000 catheter-days, respectively. A total of 10 591 (0.18%) HAIs caused by multidrug-resistant organisms were identified. Carbapenem non-susceptibility rates were highest in Acinetobacter species (53.86%) and Pseudomonas aeruginosa (21.60%). Forty-six percent (2 712 258/5 868 147) of inpatients were receiving at least one antimicrobial during this survey. CONCLUSIONS: This survey indicated the relatively lower prevalence of HAIs but higher antimicrobial using in Guangdong Province compared with other mid to low-income and high-income countries. Further studies are warranted to elucidate which HAI-related indicators are the best measures of HAI performance and thus allow improvements leading to better patient outcomes.

Comprehensive Evaluation of Visual Function in Patients With Orbital Fracture by Visual Electrophysiology and Visual Field Examination.

OBJECTIVE: At present, the effect of the visual electrophysiology and vision field examination in patients with orbital blowout fracture is rarely studied. So, the authors investigate the value of visual electrophysiology and vision field examination in the diagnosis of ocular contusion. METHODS: The position and range of fracture of 81 patients were determined by computed tomography (CT) scanning. Visual evoked potential (VEP), electroretinogram (ERG), and mfERG were vision field examination detected in 81 patients and the results were compared with those of contralateral healthy eyes. In addition, visual electrophysiology and vision field examination in diagnosis of eye contusion was analyzed and the correlation of the VEP, ERG, mfERG injury duration, and visual acuity was further analyzed. RESULTS: The visual acuity of orbital fractures was significantly decreased compared with that in the uninjured eyes (t = 2.181, P = 0.032). Compared injured eyes and normal eyes in 54 patients, b wave of Max-ERG and Cone-ERG implied value extension (t = -2.426, P = 0.025; t = -2.942, P = 0.014), P-VEP P100 Peak duration and amplitude significantly extended (t = 3.162, P = 0.007; t = 9.314, P = 0.000), and F-VEP P1 amplitude decreased significantly (t = 3.362, P = 0.004). mfERG showed that the injured eye central reaction was significantly decreased (t = 8.727, P = 0.000). There was a significant correlation between P-VEP P100 amplitude and visual acuity (r = 0.067, P = 0.000). But there was no significant correlation between the P100 peak value, amplitude of P-VEP, mfERG central reaction, and injured days, respectively. There was significant difference between 2 groups with average visual acuity and mean defect value (t = 3.253, 3.461, P = 0.006, 0.003). There was statistical means the difference in P-VEP abnormal group, visual field abnormal group, and combined detection abnormal groups, the abnormal rate increased significantly (χ = 3.931, P < 0.01). CONCLUSION: Orbital floor fracture can lead to optic nerve damage and also may be associated with decreased macular function. The combination analysis of visual electrophysiology and vision field examination is beneficial to early diagnosis of ocular trauma and can improve the positive rate in clinic practice.

Postoperative Improvement of Diplopia and Extraocular Muscle Movement in Patients With Reconstructive Surgeries for Orbital Floor Fractures.

OBJECTIVE: With orbital floor fracture incidence rates increasing year by year, many patients require surgical treatment to improve diplopia, limitation of extraocular muscle movement (EOM), enophthalmos, and midface appearance. With the use of high-density polyethylene, titanium screws, titanium plate, and titanium mesh to repair an orbital floor fracture, enophthalmos and midfacial deformity correction procedures have made great progress. However, attenuating diplopia and the limitation of EOM are still difficult problems to prevent. METHODS: The clinical data of 92 patients with reconstructive surgeries after orbital floor fracture were prospectively studied. The position, range of fracture, and incarceration of extraocular muscles were determined by computed tomography scanning. A Hess screen and a synoptophore examination were used to determine the EOM and diplopia. The Hess area ratio (HAR%) and the grade of diplopia were measured before and 1, 3, and 6 months after surgery. Diplopia was evaluated, and the severity was recorded accordingly. RESULTS: Diplopia rates in patients with simple orbital floor fracture showed a significant difference preoperatively and postoperatively at 1 and 3 months (P < 0.05) compared with diplopia rates at 6 months and 12 months after operation, which had no significant difference (P > 0.05). There was a statistically significant difference (P < 0. 05) among patients with an orbital floor fracture who had an operation within 3 weeks or more than 3 months after injury. Compared with preoperative and postoperative findings at 1 and 3 months, the limitation of EOM in patients with orbital floor fractures had a significant difference (P < 0.05); however, compared with 3 and 6 months after operation, there was no significant difference (P > 0.05). There was a statistically significant difference (P < 0.05) in patients with orbital floor fractures having had an operation within 3 weeks and more than 3 months after injury. The difference of improvement for diplopia after operation among HAR% < 65%, 65% ≤ HAR% ≤ 85%, and HAR% >85% groups were statistically significant (P <0.05). Postsurgically, the HAR% of the patients was improved, and the difference of HAR% between patients before and after the operation was statistically significant (P < 0.05). CONCLUSION: Surgical management can effectively improve diplopia and EOM disorder of patients with orbital floor fractures. Improvement statistics were calculated by a Hess screen and a synoptophore. Hess area ratio is a useful method to convert the Hess screen into a numerical value and can therefore be used to compare patients in clinical treatment of orbital wall fracture.

The effect of HLA on immunological response to hepatitis B vaccine in healthy people: a meta-analysis.

BACKGROUND AND AIM: Evidence is accumulating that several markers in the human leukocyte antigen (HLA) region have been associated with decreased or increased antibody response to hepatitis B vaccine in different individuals. This meta-analysis is to assess the associations of HLA class II DRB1 and DQB1 alleles with immunologic response to hepatitis B vaccine in healthy people. METHODS: A systematic review of cohort studies in healthy people was performed. We searched databases for relevant studies that were published in English or Chinese up to February 17, 2012. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) of HLA alleles response to hepatitis B vaccine were pooled by using of a fixed-effects or random-effects model depending on absence or presence of significant heterogeneity. All statistical tests were two-sided. RESULTS: Fifteen studies were included in this meta-analysis after scanning 774 potentially relevant articles. A total of 2308 subjects (including 1215 responders, 873 nonresponders and 220 control populations) were included. For DRB1 alleles, pooled ORs showed that three HLA variants, DRB1*01, DRB1*1301 and DRB1*15 were associated with a significant increase antibody response to hepatitis B vaccine, their pooled ORs were 2.73, 5.94 and 2.29 respectively. While DRB1 *03 (DRB1*0301), DRB1*04, DRB1*07 and DRB1*1302 were opposite, their pooled ORs were 0.55(0.42), 0.57, 0.24 and 0.25 respectively. And for DQB1 alleles, pooled ORs showed that DQB1*05 (DQB1*0501), DQB1*06, DQB1*0602 were associated with a significant increase antibody response to hepatitis B vaccine. Their merger ORs were 1.85, 2.35, 2.34 and 3.32 respectively. While DQB1*02 (pooled OR=0.27) was adverse. Sensitivity and specificity analysis of HLA alleles showed that DRB1*1301and DQB1*0602 had high specificity (94.2% and 90.1%) but low sensitivity (25.1% and 26.3%), respectively. CONCLUSION: It was suggested that specific HLA class II alleles (DRB1 and DQB1) were associated with antibody response to HepB.

[Three-dimensionally preformed titanium mesh plates for posttraumatic complex orbital bone fracture reconstruction].

OBJECTIVE: To evaluate the outcomes of the clinical application of three-dimensionally preformed titanium mesh plates for posttraumatic complex orbital bone fracture reconstruction. METHODS: Thirteen patients (13 eyes) manifested with complex orbital fractures (including orbital-zygomatic-maxillary bone fracture in 6 patients, nasal-orbital-ethmoid bone fracture in 5 patients and complex multiple periorbital bone fracture in other 2 patients) underwent the reconstructive surgery by using three-dimensionally preformed titanium mesh plates. Eight cases underwent high density porous polyethylene implantation simultaneously. Evaluation of enophthalmos, eyeball movement, and orbit CT scan were taken pre- and post-operatively. RESULTS: The average enophthalmos was (3.9 ± 1.7) mm and the position of the affected eyeball was (3.1 ± 2.6) mm bellow the contralateral side preoperatively. Twelve patients suffered from eyeball movement restriction, including grade I in 4 cases, grade II in 7 cases and grade III in 2 cases. During the 3 to 6 months post operative follow-up, enophthalmos was completely corrected in 10 patients while the other 3 patients had residual 1.0 mm enophthalmos. The affected eyeballs were repositioned in 8 cases and 3 cases had residual 1 mm lower position and 2 cases with a 1 mm higher positioned eyeball. Eye movement was not restricted in 8 patients, whereas 3 patients had grade I movement restriction and 2 patients had grade II movement restriction. There were no rejection, infection and other complications during follow-up. CONCLUSIONS: Three-dimensionally preformed titanium mesh plates can be used to reconstruct posttraumatic complex orbital bone fractures in order to improve the orbital volume and to correct enophthalmos effectively.