Establishment of extensively drug-resistant Pseudomonas aeruginosa pneumonia model in rat

Objective:To establish extensively drug-resistant Pseudomonas aeruginosa(XDR-PA)infection-induced pneumonia model in rats.Methods:Twenty-four male SD rats were randomly divided into blank group,low bacterial group,medium bacterial group,and high bacterial group.The low,medium and high bacterial groups were given intratracheal instillation of 0.1 mL of bacterial suspension(bacterial concentration in turn is 7.5×10^(9),3×10^(10),6×10^(10)CFU/mL),while the blank group were given the same volume of sterile normal saline.After modeling,the general conditions of rats in each group were observed,including mental state,hair,respiration,activity,eating,weight,and the survival curve was drawn.The pathological characteristics of lung tissue and the infiltration of inflammatory cells were observed.Pathogenic identification of each group was carried out by bacterial culture of lung tissue homogenate.Results:The general state of the blank group was normal,and the rats in other groups showed signs of mental depression,bristling,shortness of breath,even oral and nasal bleeding,decreased food intake and activity,and significant weight loss,and different degrees of death within 48 hours,the difference was statistically significant(P<0.05).Pathological results showed that the alveolar structure of rats in the blank group was complete,and the alveolar space was clear without exudation.The lung tissue of the low and medium bacterial groups showed obvious inflammatory cell infiltration,alveolar structure destruction,alveolar septum thickening,interstitial edema,but the pathological damage of the medium group was more severe,with a mortality rate of up to 50%,and the mortality rate of the low bacterial group was 17%.In the high bacterial group,red blood cells,inflammatory cells and a large amount of fibrin-like exudation can be seen in the alveolar space,which has the pathological characteristics of acute respiratory failure,and the mortality rate is as high as 67%.The results of bacterial culture of lung tissue homogenate showed that the blank group had no bacterial colonies,while PA colony growth can be seen in low,medium and high bacterial groups.Conclusion:9 Intratracheal instillation of low bacterial count(0.1 mL of 7.5×10^(9) CFU/mL)XDR-PA bacterial suspension can successfully construct a rat pneumonia model of XDR-PA infection.

Prolonged use of bedaquiline in two patients with pulmonary extensively drug-resistant tuberculosis: Two case reports

BACKGROUND Bedaquiline is among the prioritized drugs recommended by the World Health Organization for the treatment of extensively drug-resistant tuberculosis(XDRTB).Many patients have not achieved better clinical improvement after bedaquiline is stopped at 24 wk.However,there is no recommendation or guideline on bedaquiline administration beyond 24 wk,which is an important consideration when balancing the benefit of prognosis for XDR-TB against the uncertain safety concerning the newer antibiotics.CASE SUMMARY This paper reported 2 patients with XDR-TB(a female of 58 years of age and a female of 18 years of age)who received bedaquiline for 36 wk,as local experience to be shared.The 2 cases had negative cultures after 24 wk of treatment,but lung imaging was still positive.After discussion among experts,the consensus was made to bedaquiline prolongation by another 12 wk.The 36-wk prolonged use of bedaquiline in both cases achieved a favorable response without increasing the risk of cardiac events or new safety signals.CONCLUSION Longer regimen,including 36-wk bedaquiline treatment,might be an option for patients with XDR-TB.More studies are needed to explore the effectiveness and safety of prolonged use of bedaquiline for 36 wk vs standard 24 wk in the treatment of multidrug-resistant/XDR-TB or to investigate further the biomarkers and criteria indicative for extension of bedaquline to facilitate clinical use of thisnovel drug.

Successful treatment of pyogenic ventriculitis caused by extensively drug-resistant Acinetobacter baumannii with multi-route tigecycline: A case report

BACKGROUND Pyogenic ventriculitis caused by extensively drug-resistant Acinetobacter baumannii(A.baumannii)is one of the most severe complications associated with craniotomy.However,limited therapeutic options exist for the treatment of A.baumannii ventriculitis due to the poor penetration rate of most antibiotics through the blood-brain barrier.CASE SUMMARY A 68-year-old male patient with severe traumatic brain injury developed pyogenic ventriculitis on postoperative day 24 caused by extensively drug-resistant A.baumannii susceptible to tigecycline only.Successful treatment was accomplished through multi-route administration of tigecycline,including intravenous combined with continuous ventricular irrigation plus intraventricular administration.The pus was cleared on the 3rd day post-irrigation,and cerebrospinal fluid cultures were negative after 12 d.CONCLUSION Our findings suggest that multi-route administration of tigecycline can be a therapeutic option against pyogenic ventriculitis caused by extensively drugresistant A.baumannii.

Clinical analysis of colistin sulfate in the treatment of pneumonia caused by carbapenem-resistant Gram-negative bacteria

BACKGROUND Multidrug-resistant Gram-negative bacteria,exacerbated by excessive use of antimicrobials and immunosuppressants,are a major health threat.AIM To study the clinical efficacy and safety of colistin sulfate in the treatment of carbapenem-resistant Gram-negative bacilli-induced pneumonia,and to provide theoretical reference for clinical diagnosis and treatment.METHODS This retrospective analysis involved 54 patients with Gram-negative bacilli pneumonia admitted to intensive care unit of The General Hospital of the Northern Theater Command of the People's Liberation Army of China from August 2020 to June 2022.After bacteriological culture,the patients'airway secretions were collected to confirm the presence of Gram-negative bacilli.The patients were divided into the experimental and control groups according to the medication used.The research group consisted of 28 patients who received polymyxin sulfate combined with other drugs through intravenous,nebulization,or intravenous combined with nebulization,with a daily dosage of 1.5–3.0 million units.The control group consisted of 26 patients who received standard dosages of other antibiotics(including sulbactam sodium for injection,cefoperazone sodium sulbactam for injection,tigecycline,meropenem,or vaborbactam).RESULTS Of the 28 patients included in the research group,26 patients showed improvement,treatment was ineffective for two patients,and one patient died,with the treatment efficacy rate of 92.82%.Of the 26 patients in the control group,18 patients improved,treatment was ineffective for eight patients,and two patients died,with the treatment efficacy rate of 54.9%;significant difference was observed between the two groups(P<0.05).The levels of white blood cell(WBC),procalcitonin(PCT),and C-reactive protein(CRP)in both groups were significantly lower after treatment than before treatment(P<0.05),and the levels of WBC,PCT,and CRP in the research group were significantly lower than those in the control group(P<0.05).Compared with before treatment,there were no significant changes in aspartate aminotransferase,creatinine,and glomerular filtration rate in both groups,while total bilirubin and alanine aminotransferase decreased after treatment(P<0.05)with no difference between the groups.In patients with good clinical outcomes,the sequential organ failure assessment(SOFA)score was low when treated with inhaled polymyxin sulfate,and specific antibiotic treatment did not improve the outcome.Sepsis and septic shock as well as a low SOFA score were independent factors associated with good clinical outcomes.CONCLUSION Polymyxin sulfate has a significant effect on the treatment of patients with multiple drug-resistant Gram-negative bacilli pneumonia and other infections in the lungs and is safe and reliable.Moreover,the administration route of low-dose intravenous injection combined with nebulization shows better therapeutic effects and lower adverse reactions,providing new ideas for clinical administration.

Transmission of extensively drug-resistant and multidrug resistant Mycobacterium tuberculosis in families identified by genotyping

Background Diagnosis and appropriate treatment of multidrug-resistant tuberculosis （MDR-TB） remain major challenges. We sought to elucidate that persons who share a household with drug resistance tuberculosis patients are at high risk for primary drug resistance tuberculosis and how to prevent these outbreaks. Methods We used 12-locus mycobactedal interspersed repetitive unit and 7-locus variable-number tandem repeat to identify household transmission of extensively drug resistant and multiple drug resistant Mycobacterium tuberculosis in three families admitted in Shanghai Pulmonary Hospital affiliated with Tongji University. Drug susceptibility tests were done by the modified proportion method in the MGIT 960 system in the same time. Clinical data were also obtained from the subjects＇ medical records. Results All of the six strains were defined as Beijing genotype by the deletion-targeted multiplex PCR （DTM-PCR） identification on the genomic deletion RD105. Strains from family-1 had the same minisatellite interspersed repetitive unit （MIRU） pattern （232225172531） and the same MIRU pattern （3677235）. Strains from family-2 had the same MIRU pattern （2212261553323） and the same MIRU pattern （3685134）. Strains from family-3 did not have the same MIRU pattern and they differed at only one locus （223326173533, 223325173533）, and did not have the same VNTR pattern with two locus differed （3667233, 3677234）. Conclusions Household transmission exists in the three families. A clear chain of tuberculosis transmission within family exists. Tuberculosis susceptibility should be considered when there is more than one tuberculosis patients in a familv. Household tuberculosis transmission could be prevented with adequate treatment of source Patients.

Molecular Detection of Carbapenemase Genes in Extensive Drug Resistant Acinetobacter baumannii Clinical Isolates from ICU Patients, Khartoum

Background: The emergence of carbapenemase producing Acinetobacter baumannii is increasingly reported nowadays and constitutes a major problem to the intensive care unit (ICU) patients with notable extensive-drug resistance ability. The study investigates carbapenemase producing A. baumannii strains exhibiting an extensively drug-resistant (XDR) phenotype, isolated from ICU patients in Khartoum. Methods: A total of 100 nonduplicate Gram-negative coccobacilli strains were obtained from microbiology laboratory of ICU patients’ clinical isolates. Molecular identification of A. baumannii was performed by targeting 16S rRNA gene using specifically designed primers. Then, XDR strains were determined by susceptibility testing (disc diffusion). For detection of carbapenemase genes Polymerase chain reaction (PCR) was carried out. Result: Of 100 ICU clinical isolates, 38 (38.0%) was confirmed A. baumannii strains, those strains showed 100% carbapenem resistance and 60.5% extensive drug resistance to the antibiotics tested. The frequency of carbapenemase producer was 57.9% (22/38) of carbapenem resistance A. baumannii (CRAB). The most common carbapenemase associated with resistance was blaOXA gene followed by blaNDM and blaGES A. baumannii isolates. The co-occurrence of blaOXA-48-like and blaNDM, blaOXA-23-like and blaOXA-51, and blaNDM-1 and blaOXA-51 was detected in 22.7%, 18.2% strains and 4.5% respectively. A unique characteristic of our findings was the coharbouring of the genes blaNDM-1, blaOXA-23-like, blaOXA-51 and blaOXA-143 in 9.1% strains (2/22), and this was the first report in the Khartoum city, Sudan. Conclusion: We have demonstrated for the first time a high prevalence of XDR-carbapenemase producing A. baumannii clinical isolates from ICU patients in Khartoum. Also an emergent blaOXA-143 was reported as High-Risk Clones. This highlights the routine mentoring of XDR-carbapenemase producing A. baumannii to avoid clone dissemination in our region hospitals.

The Role of Pyridoxine in the Prevention and Treatment of Neuropathy and Neurotoxicity Associated with Rifampicin-Resistant Tuberculosis Treatment Regimens: A Topic Review

Rifampicin-resistant tuberculosis (RR-TB) is a global public health problem caused by mycobacterium tuberculosis resistant to Rifampicin. Drug-induced peripheral neuropathy and neurotoxicity are well-known adverse effects of treatment regimens that cause significant morbidity. Pyridoxine is often added to treatment regimens for the prevention and/or treatment of these side effects. The basis and effectiveness of this practice are unclear. We conducted a systematic review to evaluate the effectiveness of pyridoxine in preventing and/or treating neuropathy and neurotoxicity associated with RR-TB treatment. We included studies with patients with RR-TB who experienced neuropathy or neurotoxicity attributed to RR-TB regimens and were given pyridoxine. Our findings showed contradicting evidence on the use of pyridoxine for preventing or treating neurotoxicity due to cycloserine in the treatment of RR-TB. Moreover, pyridoxine did not have a protective effect against neuropathy and/or neurotoxicity caused by other RR-TB regimens that do not contain isoniazid. In conclusion, we found that withdrawing or withholding medications such as linezolid, cycloserine, thioamides, fluoroquinolones, and ethambutol, implicated in causing neuropathy or neurotoxicity was more effective than using pyridoxine to stop the progression of symptoms, and in some instances, led to their reversal over time.

2014年上海市细菌耐药性监测

目的了解2014年上海市细菌耐药性监测情况。方法采用纸片扩散法(K-B法)或自动化仪器法对上海市40所医院的临床分离菌进行药敏试验。包括28所三级医院和12所二级医院,其中含3所儿童医院。采用CLSI 2014年版标准判断结果。结果总计102 113株临床分离菌,革兰阳性菌27 482株,占26.9%;革兰阴性菌74 631株,占73.1%。MRSA和MRCNS的检出率分别为47.4%和79.8%。MRSA、MRCNS在二级医院和三级医院的平均检出率分别为51.1%、79.9%和46.6%、79.8%。葡萄球菌属中未发现万古霉素和替考拉宁耐药株。845株儿童非脑膜炎分离株中青霉素敏感(PSSP)、中介(PISP)和耐药(PRSP)株的检出率分别为70.1%、14.6%和15.4%;167株成人分离株的PSSP、PISP和PRSP分别为97.6%、1.2%和1.2%。发现67株屎肠球菌和14株粪肠球菌耐万古霉素。根据PCR测序,多数万古霉素耐药肠球菌为van A和van M基因型。大肠埃希菌、克雷伯菌属(肺炎克雷伯菌和产酸克雷伯菌)和奇异变形杆菌中ESBL的检出率分别为59.4%、35.9%和30.1%。上述ESBL菌株在二级医院和三级医院的检出率分别为61.6%、31.6%、35.0%和58.9%、36.9%、29.5%。肠杆菌科细菌对碳青霉烯类抗生素仍高度敏感,对亚胺培南和美罗培南的总耐药率均为7.0%。鲍曼不动杆菌、肺炎克雷伯菌、铜绿假单胞菌和大肠埃希菌中有少数对所有测试药物耐药的广泛耐药株。分离自尿液标本中的肠球菌属和大肠埃希菌对磷霉素的耐药率低。结论细菌耐药性仍对临床构成严重威胁,临床需合理规范应用抗菌药物,避免耐药株的广泛传播。

2016年上海市细菌耐药性监测

目的了解2016年上海市细菌耐药性监测结果。方法采用纸片扩散法或自动化仪器法对上海市47所医院的临床分离菌进行药敏试验。包括28所三级医院(床位数31 373张)和19所二级医院(床位数16 311张)。采用CLSI 2016年版标准判断结果。结果 12 2 548株临床分离菌,革兰阳性菌35 522株,占29.0%;革兰阴性菌87 026株,占71.0%。分离菌二级医院和三级医院分别占28.9%和71.1%;其中革兰阳性菌和革兰阴性菌在二、三级医院中分别占25.8%和74.2%、30.3%和69.7%。MRSA和MRCNS的检出率分别为48.7%和77.2%。MRSA、MRCNS在二级医院和三级医院的平均检出率分别为55.9%、73.3%和45.9%、78.6%。葡萄球菌属中未发现万古霉素耐药株。1 111株儿童非脑膜炎肺炎链球菌中青霉素敏感(PSSP)、中介(PISP)和耐药株(PRSP)的检出率分别为77.4%、13.2%和9.4%;上述细菌在二级医院中分别占97.8%、2.2%、0;在三级医院中分别占76.5%、13.7%、9.8%。285株成人分离肺炎链球菌PSSP、PISP和PRSP分别为94.0%、4.2%和1.8%;上述细菌在二级医院中分别占93.7%、5.3%、1.0%;在三级医院中分别占94.2%、3.7%、2.1%。发现37株屎肠球菌(二级医院14株,三级医院23株)和25株粪肠球菌(均分离自三级医院)耐万古霉素。根据PCR测序,多数万古霉素耐药肠球菌(VRE)为van A基因型。大肠埃希菌、肺炎克雷伯菌和奇异变形杆菌中ESBL的检出率分别为52.2%、30.9%和29.8%。上述产ESBL菌株在二级医院和三级医院的检出率分别为55.1%、33.6%、34.0%和51.0%、29.7%、28.0%。肠杆菌科细菌对碳青霉烯类抗生素仍高度敏感,对亚胺培南、美罗培南的总耐药率分别为8.9%、9.1%,二级医院和三级医院中耐药率分别为6.6%、7.1%和9.9%、10.0%。鲍曼不动杆菌、肺炎克雷伯菌、铜绿假单胞菌和大肠埃希菌中出现对所有测试抗菌药物耐药的广泛耐药株,在二级医院和三级医院分别为223株、63株、10株、4株和224株、201株、22株、9株。结论目前临床主要病原菌对常用抗菌药物的耐药性仍极严重,对医疗机构构成严重威胁,需引起高度重视并采取有效感控措施。

2015年上海市细菌耐药性监测

目的了解2015年上海市细菌耐药性监测结果。方法采用纸片扩散法或自动化仪器法对上海市44所医院的临床分离菌进行药敏试验,包括27所三级医院(其中含3所儿童医院)和17所二级医院。采用美国临床和实验室标准化协会(CLSI)2015年版标准判断结果。结果 107 853株临床分离菌,革兰阳性菌31 585株,占29.3%;革兰阴性菌76 268株,占70.7%。MRSA和MRCNS的检出率分别占各自菌种的46.9%和74.2%。MRSA、MRCNS在二级医院和三级医院的平均检出率分别为53.6%、70.3%和44.3%、75.6%。葡萄球菌属中未发现万古霉素和利奈唑胺耐药株。1 021株肺炎链球菌儿童非脑膜炎分离株中青霉素敏感(PSSP)、中介(PISP)和耐药(PRSP)株的检出率分别为77.8%、13.3%和8.9%。232株成人分离株PSSP、PISP和PRSP分别为88.4%、5.2%和6.4%。检出51株屎肠球菌和3株粪肠球菌耐万古霉素。根据PCR测序,多数耐万古霉素肠球菌为vanA基因型。大肠埃希菌、克雷伯菌属(肺炎克雷伯菌和产酸克雷伯菌)和奇异变形杆菌中ESBL的检出率分别为57.0%、32.3%和41.5%。上述ESBL菌株在二级医院和三级医院的检出率分别为58.0%、29.0%、45.5%和56.5%、33.9%、40.2%。肠杆菌科细菌对碳青霉烯类抗生素仍高度敏感,对亚胺培南和美罗培南的总耐药率分别为7.4%和7.7%。鲍曼不动杆菌、肺炎克雷伯菌、铜绿假单胞菌和大肠埃希菌中有少数菌株为广泛耐药株。结论细菌耐药性仍对临床构成严重威胁,需引起高度重视,避免耐药株的广泛传播。

震后土壤微生物分布状况研究

在SPSS11.5 for Window和ArcGIS9.2平台上,对地震灾区一个典型代表区域土壤微生物的分布状况及其影响因素进行了研究。结果表明：研究区域土壤微生物总量平均值为2.51×107CFU/g干土,三大类微生物中细菌所占比例最大,为总量的84.50%,其次为放线菌和真菌;水平方向上,区域内土壤微生物主要分布在中南部;垂直方向上细菌主要分布在20～40 cm土层,放线菌和真菌主要分布在0～20 cm土层;灾区搭建临时帐篷和建造板房等对土壤造成的压实对区域内土壤微生物数量无显著影响;区域内水田、旱地、林地三类生态系统微生物数量无显著差异;土壤因子中只有有效磷与放线菌数量存在显著的线性相关关系。

Activities of Biapenem against Mycobacterium tuberculosis in Macrophages and Mice

Objective To assess the activities of biapenem against multidrug-resistant and extensively drug-resistant Mycobacterium tuberculosis. Methods Biapenem/clavulanate(BP/CL) was evaluated for in vitro activity against Mycobacterium tuberculosis(Mtb) multidrug-resistant(MDR) isolates, extensively drug-resistant(XDR) isolates, and the H37 RV strain. BP/CL activity against the H37 Rv strain was assessed in liquid cultures, in macrophages, and in mice. Results BP/CL exhibited activity against MDR and XDR Mtb isolates in liquid cultures. BP/CL treatment significantly reduced the number of colony forming units(CFU) of Mtb within macrophages compared with control untreated infected macrophages. Notably, BP/CL synergized in pairwise combinations with protionamide, aminosalicylate, and capreomycin to achieve a fractional inhibitory concentration for each pairing of 0.375 in vitro. In a mouse tuberculosis infection model, the efficacy of a cocktail of levofloxacin + pyrazinamide + protionamide + aminosalicylate against Mtb increased when the cocktail was combined with BP/CL, achieving efficacy similar to that of the positive control treatment(isoniazid + rifampin + pyrazinamide) after 2 months of treatment. Conclusion BP/CL may provide a new option to clinically treat MDR tuberculosis.

金属β内酰胺酶基因bla_(NDM)重组酶聚合酶扩增方法的建立

目的建立一种基于重组酶聚合酶(recombinase polymerase amplification,RPA)扩增方法金属β内酰胺酶基因bla_(NDM)的快速检测方法,为广泛耐药菌基因类型的确定提供技术支持。方法遵照重组酶聚合酶扩增引物和探针设计原则,以bla_(NDM)基因特异性序列为靶基因,设计相应的RPA扩增引物和探针。取梯度稀释已知拷贝数的DNA模板和致病菌核酸样品进行各扩增体系的RPA扩增实验,分析扩增体系的敏感性、特异性和重复性特征以便筛选和评价bla_(NDM)基因的RPA扩增体系。结果 3组扩增体系的引物和探针能够有效的扩增靶基因,检出限达到2×10~2copys/反应,与其他细菌样品无非特异性扩增反应,能够在2～7 min内实现靶基因有效扩增。结论建立了金属β内酰胺酶基因bla_(NDM)的重组酶聚合酶扩增体系,该反应迅速,检出限较低,具有较高的特异性,适用于耐药菌的现场检测。

Human mpox co-infection with advanced HIV-1 and XDR-TB in a MSM patient previously vaccinated against smallpox:A case report

Mpox is a zoonotic infectious disease caused by the mpox virus(MPXV).Historically,the majority of mpox cases have been documented in Central Africa.However,since May 2022,there has been a notable rise in reported cases from regions beyond Africa.Currently,over 110 countries spanning Europe,North America,South America,Asia,and other territories have reported mpox infections.This report details a case involving a patient who identifies as a man who has sex with men(MSM)and is concurrently infected with MPXV,human immunodeficiency virus type 1(HIV-1),Pneumocystis jiroveci,as well as extensively drug-resistant tuberculosis(XDR-TB).This patient had also received a vaccination for smallpox in the past.Additionally,we provide photographic documentation charting the progression of dermatological manifestations associated with mpox.This case highlights the significance of sexual intercourse as a crucial mode of transmission for mpox.The rapid and widespread dissemination of the MPXV across various regions,especially among MSM communities,underscores the importance of enhancing preventive education efforts targeted at high-risk populations.