Direct and Residual Microbicidal Efficacy of Various Antiseptics against Multi-Drug Resistant Bacteria

Background: Infections in ICU’s patients are known to often originate from the colonization of wounds by the patient’s endogenous microbiota, and to eventually lead to secondary sepsis. Aim: to compare in vitro the direct and residual effects after different exposure times of 4% chlorhexidine, and of 0.1% and 0.04% polyhexanide (in gel and solution forms), on ATCC-microorganisms, and too, on bacterial strains obtained from ICU patients. Methods: We used wild multi-drug resistant strains recently obtained from the wounds of patients hospitalized at ICU and reference strains from the American Type Culture Collection (ATCC). Chlorhexidine 4% was studied as a reference solution. The direct and residual effects of the 0.1% and 0.04% polyhexanide, in gel and solution forms, were analyzed using cotton germ carriers. To evaluate the direct effect, we exposed the strains to the antiseptic. To assess the residual effect, the germ-carriers were impregnated with antiseptic and were allowed to dry before we contaminated them. We inoculated the germ carriers in a culture medium with an inhibitor of antiseptic effect to count the number of surviving microorganisms. Findings: 0.1% Polyhexanide solution proved a direct and residual efficacy after 24 hours equivalent to 4% chlorhexidine. Is very important to highlight that this great efficacy did not change according to whether they were ATCC or multidrug-resistant strains. Conclusions: 0.1% polyhexanide demonstrated a great direct and residual efficacy (like 4% chlorhexidine), against multi-drug resistant strains isolated from ICU’s patients. Moreover, due to its few cytotoxicity against keratinocytes and fibroblasts can be an optimal antiseptic for burns, wounds or ulcers.

<i>In Vitro</i>Antibacterial Activity of Flavonoid Extracts of Two Selected Libyan Algae against Multi-Drug Resistant Bacteria Isolated from Food Products

This study aimed to evaluate the antibacterial activity of flavonoids extracted from two Libyan brown algae namely Cystoseira compressa and Padina pavonica using microwave-assisted extraction method against pathogenic bacteria isolated from meat, meat products, milk and dairy products (Staphylococcus aureus subsp. aureus (5 isolates), Bacillus cereus (3 isolates), Bacillus pumilus (1 isolate), Salmonella enterica subsp. enteric (4 isolates) and Enterohaemor-rhagic Escherichia coli O157 (EHEC O157) (4 isolates)). All of these isolates were muti-drug resistant with high MAR index. The results showed that C. compressa extract exhibited better and stronger antibacterial activities against the seventeen tested isolates with inhibition zones diameter ranged from 14 - 22 mm compared to P. pavonica extract which showed positive effect against 9 isolates with low inhibition zone ranged from 11 - 16.5 mm. Flavonoids extracted from C. compressa also displayed the best spectrum of bactericidal effect with a ratio MBC/MIC ≤ 4 obtained on all susceptible tested bacterial strains. Flavonoids and proanthocyanidins significantly contributed to the antibacterial properties. The mode of action of these active extracts is under investigation.

Bacterial contamination of orally-consumed crude herbal remedies:A potential source for multi-drug resistant pathogens in man

Objective:The acceptability of herbal remedies for alleviating discomforts and ill-health has become very popular, on the account of the increasing cost of allopathic medicine for personal health maintenance.The observable non-adherence of herbalists to the established World Health Organization(WHO) / National Agency for Food and Drug Administration Control(NAFDAC) regulations for the quality control of herbal medicines is an issue for concern.In view of this,34 popular and widely consumed crude herbal remedies in southwestern,Nigeria were screened for compliance with standard limits for bacterial contamination,bacteria flora and their antibiotic susceptibility pattern.Methods:Isolates recovered from samples were identified using the cultural, morphological and biochemical characteristics.They were also tested for drug sensitivity using standard procedures. Results:A heavy bacteria load ranging from 3.00×10~3-9.58×10~5 CFU/ML and 1.20×10~5- 5.41×10~5 CFU/ML was observed for water and spirit extracted preparations respectively.The bacteria flora cum contaminants were:Staphylococcus aureus,Bacillus cereus,Bacillus subtilis,Pseudomonas aeruginosa, Micrococcus luteus,Lactobacillus plantarum,Klebsiella pneumoniae,Escherichia coli,streptococcus,Shigella, Neisseria,Arthrobacter,Kurthia and Clostridium species.All the isolates were multi-drug resistant(MDR) strains.Conclusion:The crude herbal preparations consumed in Nigeria failed to comply with the internationally recognized standards regarding bacteria load and flora.The presence of MDR pathogens is of greatest concern. It poses a great risk to consumers health and could be a source of introducing MDR organisms into the human population.There is the need for the enforcement of established guidelines to ensure the safety of these preparations.

Analysis of Clinical Symptoms Improvement in Treatment of Severe Pneumonia Caused by Multi-drug Resistant Bacterial Infection by Bronchoscopy Alveolar Lavage

Objective:To explore the effects of bronchoscopy alveolar lavage in the treatment of severe pneumonia caused by multiple drug bacterial infection.Methods:A total of 84 patients with severe pneumonia infected by multi-drug resistant bacteria were randomly selected from Kunming Second People's Hospital,which is our hospital from January 2019 to December 2020 for this research.They were divided into a reference group and a study group using a digital table method,with 42 cases in each group.The reference group was given the routine treatment,the research group performed bronchoscopy alveolar lavage on this basis to observe the curative effect.Results:Before treatment,there was no significant difference in serum factor indexes and blood gas analysis indexes between the two groups of patients,P>0.05.After treatment,the time of fever,cough,moist rales disappearing and infection control time in the study group were shorter than those in the reference group,P<0.05.Serum tumor necrosis factorα(TNF-α),interleukin-6(IL-6)and interleukin-8(IL-8)levels were lower than the reference group,and the arterial partial pressure of oxygen(PO2)and oxygen saturation(SO2)were both lower than the reference group,P<0.05.The effective rate of the treatment in the study group was higher than that in the reference group,P<0.05.Conclusion:Bronchoscopic alveolar lavage treatment can effectively improve the clinical symptoms of patients with severe pneumonia caused by multi-drug resistant bacterial infection,and the effects are significant.

涂片与培养方法检测痰液和肺泡灌洗液中抗酸菌诊断肺结核的管理研究

目的评价痰液和肺泡灌洗液联合抗酸菌检测的临床应用价值,为肺结核临床诊疗决策提供参考。方法以在同一周内并行痰液涂片染色查找抗酸菌和/或分枝杆菌培养检查的可疑肺结核患者为研究对象,从医院LIS系统中收集、整理2021年1月—7月的相关检测数据,分析4种检测结果的同一性与差异性。结果①在272例患者中,痰涂片、肺泡灌洗液涂片、痰培养、肺泡灌洗液培养(以下分别称为“A”“B”“C”“D”)的阳性检出率分别为14.71%(40/272)、19.49%(53/272)、25.00%(67/268)和31.90%(74/232),4种检测作为平行试验的阳性率为37.50%(102/272);②A^(+)C^(+)、A^(-)C^(+)、A^(+)C^(-)、A^(-)C^(-)、A^(-)C N(上标中的“+”“-”“N”分别代表“阳性”“阴性”“未检测”,下同)和B^(+)D^(+)、B^(-)D^(+)、B^(+)D^(-)、B^(-)D^(-)、B^(-)D^(N)结果组合分别占14.71%(40/272)、13.97%(38/272)、0、69.85%(190/272)、1.47%(4/272)和19.12%(52/272)、8.82%(24/272)、0.37%(1/272)、56.99%(155/272)、14.71%(40/272);③A^(+)B^(+)、A^(+)B^(-)、A^(-)B^(+)、A^(-)B^(-)和A^(+)D^(+)、A^(+)D^(-)、A^(+)D^(N)、A^(-)D^(+)、A^(-)D^(-)、A^(-)D^(N)、A^(N)D^(+)、A^(N)D^(-)、A^(N)D^(N)结果组合分别占14.71%(40/272)、0、4.78%(13/272)、80.51%(219/272)和19.12%(52/272)、5.51%(15/272)、4.04(11/272)、8.09%(22/272)、51.74%(140/272)、10.29%(28/272)、0.74%(2/272)、0.37%(1/272)、0.37%(1/272)。结论较通常应用痰液检测抗酸菌而言,行肺泡灌洗液抗酸菌检测可以大幅提高肺结核病原学确诊率,值得临床大力推广应用。

样本直接涂片法与液基夹层杯涂片法查找抗酸杆菌的效果比较

目的探讨液基夹层杯涂片法查找抗酸杆菌检验方法的临床应用价值。方法从广州市胸科医院医学检验科LIS系统中收集、整理2021年1月至7月痰液与支气管冲洗液主要送检临床样本的涂片染色检查和分枝杆菌培养结果,对同一患者时间间隔不超过1周的直接涂片与液基夹层杯涂片查找抗酸杆菌检验的结果进行回顾性分析。结果在241份痰液样本、178份支气管冲洗液样本和全部419份样本的检测中,直接涂片法、液基夹层杯涂片法的阳性率分别为15.35%(37/241)和13.69%(33/241)、15.17%(27/178)和12.92%(23/178)、15.27%(64/419)和13.37%(56/419)。在同期分枝杆菌培养结果阳性的65份痰液样本、50份支气管冲洗液样本和115份全部阳性样本中,直接涂片法、液基夹层杯涂片法的阳性率分别为56.52%(65/115)和50.78%(65/128)、54.34%(50/92)和45.88%(50/109)、55.56%(115/207)和48.73%(115/236)。在241份痰液样本、178份支气管冲洗液样本检测中,直接涂片阳性且液基夹层杯涂片阳性、直接涂片阳性且液基夹层杯涂片阴性、直接涂片阴性且液基夹层杯涂片阳性、直接涂片阴性且液基夹层杯涂片阴性的样本占比分别为12.03%(29/241)、3.32%(8/241)、1.66%(4/241)、82.99%(200/241)和8.99%(16/178)、6.18%(11/178)、3.93%(7/178)、80.90%(144/178)。结论液基夹层杯涂片法查找抗酸杆菌检验方法总体阳性检出率略低于直接涂片检测法,但可以发现相当比例的直接涂片法阴性的病原学阳性结核病患者,尤其是在支气管冲洗液检测中,具有一定的临床应用价值。

Antimicrobial activity of green tea extract against isolates of methicillin-resistant Staphylococcus aureus and multi-drug resistant Pseudomonas aeruginosa

Objective:To evaluate antibacterial activity of the Indonesian water soluble green tea extract,Camellia sinensis,against clinical isolates of methicillin-resistantStaphylococcus aureus (S.aureus)(MRSA)and multi-drug resistant Pseudomonas aeruginosa(MDR-P.aeruginosa).Methods:Antimicrobial activity of green tea extract was determined by the disc diffusion method and the minimum inhibitory concentration(MIC)was determined by the twofold serial broth dilutions method.The tested bacteria using in this study were the standard strains and multi-drug resistant clinical isolates of S.aureus and P.aeruginosa,obtained from Laboratory of Clinical Microbiology,Faculty of Medicine,University of Indonesia.Results:The results showed that the inhibition zone diameter of green tea extracts forS.aureus ATCC 25923 and MRSA were(18.970依0.287)mm,and(19.130依0.250)mm respectively.While the inhibition zone diameter forP.aeruginosa ATCC 27853 and MDR-P.aeruginosawere(17.550依0.393)mm and(17.670依0.398)mm respectively.The MIC of green tea extracts againstS.aureus ATCC 25923 and MRSA were 400μg/mL and 400μg/mL,respectively,whereas the MIC for P.aeruginosa ATCC 27853 and MDR-P.aeruginosawere 800μg/mL,and 800μg/mL,respectively.Conclusions:Camellia sinensisleaves extract could be useful in combating emerging drug-resistance caused by MRSA andP.aeruginosa.

Current concepts and future strategies in the antimicrobial therapy of emerging Gram-positive spontaneous bacterial peritonitis

Spontaneous bacterial peritonitis(SBP) is the most common infection in end-stage liver disease patients.SBP is defined as an ascitic fluid infection with a polymorphonuclear leucocyte count ≥ 250/mm^3 without an evident intra-abdominal surgically treatable source.Several mechanisms contribute to SBP occurrence,including translocation of gut bacteria and their products,reduced intestinal motility provoking bacterial overgrowth,alteration of the gut's barrier function and local immune responses.Historically,Gram-negative enteric bacteria have been the main causative agents of SBP,thereby guiding the empirical therapeutic choice.However,over the last decade,a worryingly increasing prevalence of Gram-positive and multi-drug resistant(MDR) SBP has been seen.Recently,the microbiological spectrum of SBP seems to have changed in Europe due to a high prevalence of Gram-positive bacteria(48%-62%).The overall proportion of MDR bacteria is up to 22%-73% of cases.Consequently,empirical therapy based on thirdgeneration cephalosporins or amoxicillin/clavulanic acid,can no longer be considered the standard of care,as these drugs are associated with poor outcomes.Theaim of this review is to describe,with an epidemiological focus,the evidence behind this rise in Gram-positive and MDR SBP from 2000 to present,and illustrate potential targeted therapeutic strategies.An appropriate treatment protocol should include daptomycin plus ceftaroline and meropenem,with prompt stepdown to a narrower spectrum when cultures and sensitivity data are available in order to reduce both cost and potential antibiotic resistance development.

Analysis of Influencing Factors and Predictive Models of Multidrug-resistant Bacterial Infection in Severe Patients

Objective:To investigate the influencing factors of multi-drug resistant bacterial infections in patients with severe disease and establish a predictive model.Methods:207 infected patients in our hospital from 2018 to May 2020 were selected for the study,of which 73 carried drug-resistant bacteria.Results:The risk factor network of people infected with multidrug resistant bacteria is higher than that of people infected with non-multidrug resistant bacteria,and the interaction between risk factors of the former is stronger.Conclusion:Antibiotics must be used appropriately after surgery.When the elderly was abnormal in indicators such as fever and procalcitonin in the ward,they should be considered as high-risk groups of MDRO infection.They need special care and preventive measures.

Unresolved issues in the prophylaxis of bacterial infections in patients with cirrhosis

Bacterial infections are highly prevalent and a frequent cause of hospitalization and short-term mortality in patients with cirrhosis. Due to their negative impact on survival, antibiotic prophylaxis for bacterial infections in high-risk subgroups of patients with cirrhosis has been the standard of care for decades. Patients with prophylaxis indications include those at risk for a first episode of spontaneous bacterial peritonitis(SBP) due to a low ascitic fluid protein count and impaired liver and kidney function, patients with a prior episode of SBP and those with an episode of gastrointestinal bleeding. Only prophylaxis due to gastrointestinal bleeding has a known and short-time duration. All other indications imply longlasting exposure to antibiotics-once the threshold requirement for initiating prophylaxis is met-without standardized criteria for re-assessing antibiotic interruption. Despite the fact that the benefit of antibiotic prophylaxis in reducing bacterial infections episodes and mortality has been thoroughly reported, the extended use of antibiotics in patients with cirrhosis has also had negative consequences, including the emergence of multi-drug resistant bacteria.Currently, it is not clear whether restricting the use of broad and fixed antibiotic regimens, tailoring the choice of antibiotics to local bacterial epidemiology or selecting non-antibiotic strategies will be the preferred antibiotic prophylaxis strategy for patients with cirrhosis in the future.

Management of Multi-Drug Resistant Methicillin Resistant <i>Staphylococcus aureus</i>Induced Pneumonia with New Antibiotic Adjuvant Entity: A Retrospective Study

Aim/Objective: Increase in incidences of pneumonia due to multi-drug resistant methicillin resistant Staphylococcus aureus (MRSA) in both community and health care settings is of great concern globally. Present study aims to retrospectively analyze the efficacy of new fixed dose combination with antibiotic adjuvant entity (FDC) in comparison with vancomycin to treat patients with multi-drug resistant MRSA pneumonia. Materials and Methods: During this retrospective study, case sheets of patients who were treated for MRSA pneumonia with vancomycin or fixed dose combination of vancomycin + ceftriaxone + adjuvant (FDC) between 20 March 2010 to 20 October 2014 at tertiary care center, were analyzed. Various demographic features, antibiotic therapy, length of treatment duration and the resulting efficacy were evaluated. Microbiological success was measured in terms of bacterial eradication, while clinical success was monitored in terms of complete omission of systemic signs and symptoms. Results: Among 136 patients analyzed, 113 cases were having positive culture for MRSA, and hence were further analyzed. Out of these 113 patients, empirical treatment with vancomycin was given in 59 patients and 54 patients were treated with FDC empirically. After initial culture reports, 22 patients showing resistance to vancomycin were shifted to FDC. Amidst all the patients, 24 (64.86%) of 37 from vancomycin group and 62 (81.57%) of 76 from FDC group achieved clinical success. 9 patients out of these failure cases were cured with FDC + colistin combination therapy. Failure rates in FDC treated patients were significantly low (6.57%) as compared to vancomycin group (13.51%). Conclusion: For the treatment of different types of multi-drug resistant MRSA pneumonia, the empirical intravenous FDC therapy was safe and well tolerated with higher efficacy than vancomycin. Most of the vancomycin failure cases responded to FDC therapy and were cured. This retrospective study also concludes that an alternative option of FDC + colistin is safe and effective to treat the patients which fail to respond to FDC monotherapy.

Multiple Antibiotic Resistant Index of Gram-Negative Bacteria from Bird Droppings in Two Commercial Poultries in Enugu, Nigeria

Antimicrobial resistance refers to the ability of microorganisms to grow in the presence of an antimicrobial agent at a concentration that will normally kill or inhibit their growth. Antimicrobial resistance has become a major global threat making treatment of infections tougher especially with high cost of treatment in humans and animals. This study was done to determine the Multiple Antibiotic Resistant Index (MARI) of Gram-negative bacteria from bird droppings in two commercial poultries in Enugu. Forty (40) samples were collected from each of the poultries. Isolates were identified by standard microbiological methods. The isolates identified were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Citrobacter spp, Proteus spp. and, Enterobacter spp. Antibiotic susceptibility testing was carried out using disc diffusion technique. The organisms were tested against pefloxacin, augmentin (amoxicillin and clavulanic acid), ceftazidime, streptomycin, ciprofloxacin, gentamycin, cephalothin, neomycin and ofloxacin. The result of the susceptibility test showed that Proteus spp had the highest resistance and MARI value of 0.5 and 1.0 respectively. The other MARI values were Escherichia coli (0.9), Klebsiella pneumonia (0.9), Pseudomonas aeruginosa (0.8), Citrobacter spp (0.8) and Enterobacter spp (0.7). These results suggest that bacterial organisms from poultry source can contribute significantly to the spread of multi-antibiotic resistant organisms. This could arise from the indiscriminate use of antibiotics in bird feeds in poultries.

The Five Years Surveillance and Trends of Antibiotic Resistance in Some Common Gram Negative Bacteria at the Vietnam Military Hospital

The study is to identify trends and levels of antibiotic resistance of some common Gram-negative strains over time. The samples were collected from Vietnam Military Hospital 103 between 2014 and 2019. A total of 405 Acinetobacter baumannii., 528 Pseudomonas aeruginosa, 741 Escherichia coli, and 352 Klebsiella pneumoniae strains were identified and antimicrobial susceptibility was by Vitek system and Etest method. The multi-drug resistance (MDR) was major proportion of four common bacteria. In particular, there is a tendency to shift from MDR to Extended drug resistance (XDR) or possibly Pan drug resistant (pPDR). A. baumannii had the highest level of antibiotic resistance, namely, carbapenem (61.5% - 82.5%) and cephalosporin (72.7% - 88.7%). P. aeruginosa resisted most of commonly antibiotics, ranging from 50% to 70%. E. coli had a high resistance with antibiotics like ampicillin (87.2% - 97.6%) and the 3rd generation cephalosporins (up to 79.6%). K. pneumoniae resisted carbapenem from 14.7% to 44.4%, and other antibiotics with the higher rate of 40%. The collected data will be a prerequisite for further studies on mechanisms and factors related to antibiotic resistant bacteria, in order to find out a rational and effective using strategy of antibiotics.

Prevalence and Antimicrobial Resistance of Gram-Negative Bacteria Isolates in Shellfish Samples from Two River Estuaries in South-South Nigeria

Antibiotic resistant bacteria pathogens remain the leading cause of shellfish borne diseases and a major health threat to humans worldwide. The objectives of this study were to isolate, identify, and determine the antibiotic resistance patterns of Gram-negative bacteria from shellfish. We analyzed a total of 540 shellfish (117 clams, 88 oysters, and 136 periwinkles) samples collected from different vendors at Iko and Douglas Creeks in Akwa Ibom State, South-South Nigeria. Conventional cultural techniques, morphological, biochemical characteristics, and PCR amplification were used to identify the bacterial isolates. Antibiotic susceptibility tests (Kirby-Bauer disk diffusion method) and ESBL phenotype (disk) of the isolates were performed. One hundred and thirty-five (135) Gram-negative bacteria comprising 5 genera and 14 species were detected at a prevalence of: Alcaligenes faecalis TRB-7 38 (28.2%), Pseudomonas oryzihabitans strain KCB005 16 (11.9%), Paenalcaligenes retgerii strain B5 12 (8.9%) Pseudomonas aeruginosa JB2 10 (7.4%), Providencia stuartii DMC-28b 9 (6.7%), Alcaligenes species TLT151 8 (5.9%), Pseudomonas aeruginosa CIFRI DTSB1 7 (5.2%), Paenalcaligenes species UN24 7 (5.2%), Alcaligenes faecalis BT10 7 (5.2%), Vibrio species strain PrVy108 6 (4.4%), Pseudomonas xiamenensis C10-2 5 (3.7%), Providencia vemicola Bu15_38 4 (2.9%), Pseudomonas anguillisceptica 4029 3 (2.2%), and Pseudomonas aeruginosa N15-01092 3 (2.2%). All tested isolates showed various degrees of resistance to the thirteen antimicrobials evaluated. High levels of resistance (100%) to cefepime and imipenem were expressed by all isolates except the Providencia species. For the EBSL indicators, all isolates apart from Alcaligenes species were resistant (100%) to ceftriaxone. All Vibrio species were susceptible to norfloxacin, nalidixic acid, and ceftazidime. The identification of antibiotic resistant Gram-negative bacteria (GNARB) from shellfish in this study highlights the risk of disseminated multi-drug resistance—a serious public health concern.

快离子催化杀菌技术在南堡油田采出水处理中的应用

在油气田开采过程中需要向地层注水以补充和保持油层压力,但注入水中如果长期存在过量的硫酸盐还原菌(SRB)、铁细菌和腐生菌,就会造成管道刺漏、油藏渗透率下降等严重后果。当前南堡油田采出水处理杀菌工艺存在处理成本高、杀菌不彻底、细菌抗药性等不良因素,通过对杀菌技术进行对比,优选出快离子催化杀菌工艺,并将该装置应用于南堡油田1号人工岛采出水处理试验,分别从杀菌效果、管道的腐蚀情况、经济效益三方面进行评价。现场试验表明:快离子催化杀菌工艺可将采出水中细菌含量控制到注水标准范围之内,经济效益显著。不仅满足了注水开发需求,也为快离子催化杀菌工艺在其他区块的推广应用起到了良好的示范作用。

禁食降低肠黏膜屏障的形态学观察及对肠道细菌易位的影响

[目的 ]观察禁食对肠黏膜屏障功能的影响。 [方法 ]制备小鼠及大鼠禁食 (4 8h)模型 ;取小鼠空肠和结肠肠壁组织 ,分别制备光镜及电镜标本 ,观察肠黏膜形态学变化 ;取大鼠肠系膜前淋巴结 ,细菌培养 4 8h后观察菌落生长情况。 [结果 ]光镜下禁食组与对照组空肠相比 ,肠壁变薄 ,肠绒毛短细 ,间距变宽 ,肠黏膜上皮细胞严重缺损 ,肠组织有淤血及出血现象。结肠无明显变化。电镜下禁食组空肠和结肠与对照组相比均可见微绒毛缩短 ,数量减少 ,但紧密连接无明显变化。大鼠禁食组肠系膜前淋巴结细菌易位率为 7/ 8,较对照组 2 / 8明显升高 (P <0 .0 5 )。 [结论 ]禁食可降低肠黏膜机械屏障进而影响免疫屏障。

利用ATP生物发光法快速检测丽娃河中细菌总数

利用ATP生物发光法对丽娃河中细菌总数进行了快速检测。结果表明,丽娃河中细菌总数维持在0.72×106～1.2×107 CFU/mL,较综合整治前的水质有了明显地改善。研究了游离ATP以及浮游生物等对发光强度的影响,发现对样品采用过滤的方法进行预处理是提高ATP生物发光法精确度的一种重要手段。

杀灭硫酸盐还原菌的药剂复配与杀菌效果研究

将杀菌剂A与B进行复配,测定各个不同复配比例的最低杀灭浓度,得知,当A∶B=10∶1时,对耐药型SRB的杀菌效果最好,也好于单独使用ME、BQ3和1227的杀菌效果。把按照A:B=10:1的比例配成的药剂记为JH1杀菌剂。再将杀菌剂A与B进行复配,得出杀菌效果最好的配比JH2(A∶B=20∶1)。对比JH1和JH2可知,杀灭培养基和现场水样中的具有耐药性或非耐药性的游离和固着型SRB,JH1均优于JH2。

微生物抑制法快速检测鲜牛乳中红霉素残留

目的利用微生物抑制法快速检测鲜牛乳中红霉素残留。方法将待测的牛奶样品和空白样品经杀菌后接入乳酸菌,经过相同时间发酵后,计算待测牛奶样品发酵前后的pH变化差值与空白样品发酵前后的pH变化差值,从而判断鲜牛奶中红霉素残留的含量。结果经过单因素及正交实验,确定乳酸菌发酵产酸条件如下:接种量0.15 U/L、发酵温度40℃、菌粉溶解时间25 min、发酵时间3.5 h,利用乳酸菌发酵产酸建立了检测鲜牛奶中红霉素残留的标准曲线Y=0.024X-0.013(其中,Y为△pH,X为鲜牛乳样品中的红霉素浓度),线性相关系数R^2=0.9949,检测的灵敏度IC_(50)为29.71μg/L,检测的线性范围为0~50μg/L,加标回收率为103.54%~124.58%,同一批次内检测的变异系数为4.39%~16.46%。结论建立的检测方法可用于筛选鲜牛乳中是否有抗生素残留并进行定量检测。

夹层杯集菌离心涂片法检测抗酸杆菌对肺结核诊断的价值

目的探讨夹层杯集菌离心涂片法检测抗酸杆菌对肺结核诊断的意义。方法对614份痰标本同时进行夹层杯集菌离心涂片法与普通痰涂片法检测抗酸杆菌,比较2种方法的检出率。结果夹层杯集菌离心涂片法检测抗酸杆菌阳性率为32.28%,明显高于普通涂片法镜检法的19.87%(P<0.005)。结论夹层杯集菌离心涂片法简单省时、阳性率高,且便于进行质量控制,是一种很有推广价值的检测方法。