Antimicrobial susceptibility of bacterial isolates from community acquired infections in Sub-Saharan Africa and Asian low and middle income countries

Objective Antimicrobial resistance has arisen across the globe in both nosocomial and community settings as a consequence of widespread antibiotic consumption. Poor availability of laboratory diagnosis means that resistance frequently goes unrecognised and may only be detected as clinical treatment failure. In this review, we provide an overview of the reported susceptibility of common community acquired bacterial pathogens in Sub‐Saharan Africa and Asia to the antibiotics that are most widely used in these areas. Methods We reviewed the literature for reports of the susceptibility of prevalent pathogens in the community in SSA and Asia to a range of commonly prescribed antibiotics. Inclusion criteria required that isolates were collected since 2004 and that they were obtained from either normally sterile sites or urine. The data were aggregated by region and by age group. Results Eighty‐three studies were identified since 2004 which reported the antimicrobial susceptibilities of common bacterial pathogens. Different methods were used to assess in‐vitro susceptibility in the different studies. The quality of testing (evidenced by resistance profiles) also varied considerably. For Streptococcus pneumoniae and Neisseria meningitidis most drugs maintained relatively high efficacy, apart from co‐trimoxazole to which there were high levels of resistance in most of the pathogens surveyed. Conclusions Compared with the enormous infectious disease burden and widespread use of antibiotics there are relatively few reliable data on antimicrobial susceptibility from tropical Asia and Africa upon which to draw firm conclusions, although it is evident that many commonly used antibiotics face considerable resistance in prevalent bacterial pathogens. This is likely to exacerbate morbidity and mortality. Investment in improved antimicrobial susceptibility testing and surveillance systems is likely to be a highly cost‐effective strategy and should be complemented by centralized and readily accessible information resources.     

Susceptibility of community-acquired pathogens to antibiotics in Africa and Asia in neonates--an alarmingly short review

Objective To assess the susceptibility of community‐acquired pathogens in neonatal sepsis to commonly prescribed antibiotics in sub‐Saharan Africa and Asia since 2002. Methods Literature review in PubMed and Embase. Susceptibility was estimated for pathogens individually and stratified by region. Isolates were also classified into Gram positive and Gram negative pathogens to estimate their pooled susceptibility. Results and conclusions Only nine studies met the inclusion criteria. The available data indicated poor susceptibility to almost all commonly used antibiotics in pathogens such as Staphylococcus aureus and Klebsiella spp. Only Streptococcus pneumoniae exhibited good susceptibility to all drugs other than cotrimoxazole. The extreme scarcity of data prevents drawing any firm conclusions beyond the urgent need for more studies to identify the best treatments for neonatal sepsis in the developing world.     

2000年武汉地区产超广谱β-内酰胺酶菌种的分布及药敏分析

目的 了解产超广谱β-内酰胺酶(ESBLs)的细菌分离、分布及对抗生素的敏感性。方法 用APl或V1TEK-AMS系统(Bio’Merieux，法国)鉴定菌种，用NCCLS推荐的初筛和确证法检测产ESBLs的细菌，并用K-B法测定其对14种抗生素的敏感性。结果 2000年武汉地区的269株大肠埃希菌、202株肺炎克雷伯菌、149株阴沟肠杆菌、67株费劳地枸椽酸杆菌、43株产酸克雷伯菌中：ESBLs的检出率分别为40．9％、29．2％、20．1％、29．9％、和23．3％。产ESBLs大肠埃希菌、肺炎克雷伯菌对亚胺培南全部敏感，产ESBLs的大肠埃希菌对阿米卡星的耐药率为22．4％，对其它抗生素有不同程度的耐药。结论 产ESBLs的菌株集中在肠杆菌科菌中，以大肠埃希菌、肺炎克雷伯菌、费劳地枸椽酸杆菌的ESBLs产出最高。阴沟肠杆菌、产酸克雷伯菌ESBLs的产出应引起重视。治疗其感染时应首选亚胺培南。     

浙江省产超广谱β-内酰胺酶大肠埃希菌和肺炎克雷伯菌的基因分型

目的了解浙江省产超广谱β-内酰胺酶(ESBLs)大肠埃希菌和肺炎克雷伯菌的ESBLs基因型分布。方法对119株实验室保存的1998年9月至1999年6月浙江省各个地区临床分离的产ESBLs大肠埃希菌和肺炎克雷伯菌，采用接合试验，聚合酶链反应(PCR)，PCR产物克隆测序等方法明确ESBLs基因型。结果119株菌株中有115株产CTX—M型ESBLs阳性率为93．28％，包括88株CTX—M-14，12株CTX—M-24，6株CTX—M-22，5株CTX—M-3，2株CTX—M-9及CTX—M-27，CTX—M-28、CTX—M-29各1株；9株产SHV型ESBLs，阳性率为7．56％，包括8株SHV-12，1株SHV-5；未分离到TEM型ESBLs。有9株产2种及2种以上ESBLs，有4株未能确定ESBLs基因型。结论浙江地区产ESBLs大肠埃希菌和肺炎克雷伯菌的基因型以CTX—M-14型为主；CTX—M-29是一种新基因型ESBLs基因库登录号为AY267213。     

中国部分地区产超广谱-β内酰胺酶大肠埃希菌和肺炎克雷伯菌qnrA基因的检测

目的明确我国部分地区产超广谱-β内酰胺酶（ESBL）大肠埃希菌和肺炎克雷伯菌中qnrA基因的存在状况。方法PCR扩增产ESBL菌株，包括263株大肠埃希菌和99株肺炎克雷伯菌的qnrA基因；测序分析其基因序列。琼脂稀释法测定10种抗菌药物对qnrA基因阳性菌株的最低抑菌浓度（MIC）。接合实验和Southern杂交进行基因定位。脉冲场凝胶电泳（PFGE）分析qnrA基因阳性株的同源性。结果263株大肠埃希菌中有5株检出qnrA基因，占1，9％；99株肺炎克雷伯菌中有8株检出qnrA基因，占8，1％。13株qnrA阳性株中qnrA基因均位于可接合性质粒上。13株菌株同时携带CTX—M基因（1株CTX—M-9、5株CTX—M-14和7株CTX—M-24）。qnrA基因阳性的接合菌与受体菌J53相比，环丙沙星对前者的MIC较后者提高了4～133倍。11株环丙沙星耐药株（MIC≥4mg／L）均存在GyrA亚基的83位氨基酸和（或）87位氨基酸改变，其中8株对环丙沙星高水平耐药株（MIC≥16mg／L）同时存在ParC亚基的80位氨基酸改变。2株MIC分别为4mg／L和2mg／L的菌株GyrA和ParC两亚基均未发生改变。结论肺炎克雷伯菌中qnrA基因的携带率高于大肠埃希菌。qnrA基因单独作用仅导致低水平喹诺酮类耐药，合并gyrA和（或）parC突变导致喹诺酮类高水平耐药。     

Intracoronary blood flow velocity and transstenotic pressure gradient using sensor-tip pressure and doppler guidewires: A new technology for the assessment of stenosis severity in the catheterization laboratory

In a patient undergoing percutaneous balloon angioplasty of a stenotic proximal right coronary artery the transstenotic pressure gradient was measured using a “0.018” guidewire with a distal optical microsensor. Blood flow velocity was measured proximal to the stenosis using a “0.018” Doppler guidewire. Transstenotic pressure gradient and blood flow velocity were measured in baseline conditions and after intracoronary injection of 12.5 mg of papaverine. Coronary blood flow was calculated from the measured blood flow velocity and the corresponding cross-sectional area. The measured pressure gradients were compared with the values derived from the stenosis geometry assessed with quantitative coronary angiography (automated edge detection measurements in two orthogonal views, assuming an elliptical cross-sectional area). The measured transstenotic pressure gradient was 15 mm Hg in baseline conditions and 42 mm Hg at the peak effect of the papaverine injection. A 50% flow velocity increase was observed at peak hyperemia (time-averaged maximal flow velocity = 30 cm/s before and 45 cm/s after papaverine). The transstenotic pressure gradient calculated from the measured stenosis geometry was 20 mm Hg and 42 mm Hg in baseline and hyperemic conditions, respectively. The combined use of a pressure and a Doppler guidewire provides a complete assessment of the transstenotic pressure/coronary flow velocity relation at rest and after pharmacologically induced hyperemia and allows the characterization of stenosis hemodynamics and functional severity. © 1993 Wiley-Liss, Inc.     

Clinical relevance of an objective flow cytometry approach based on limit of detection and limit of quantification for measurable residual disease assessment in acute myeloid leukemia. A post-hoc analysis of the GIMEMA AML1310 trial

Using a multiparametric flow cytometry assay, we assessed the predictive power of a threshold calculated applying the criteria of limit of detection (LOD) and limit of quantitation (LOQ) in adult patients with acute myeloid leukemia. This was a post-hoc analysis of 261 patients enrolled in the GIMEMA AML1310 prospective trial. According to the protocol design, using the predefined measurable residual disease (MRD) threshold of 0.035% bone marrow residual leukemic cells (RLC) calculated on mononuclear cells, 154 (59%) of the 261 patients were negative (MRD <0.035%) and 107 (41%) were positive (MRD ≥0.035%). Using LOD and LOQ, we selected the following categories of patients: (i) LOD^neg if RLC were below the LOD (74; 28.4%); (ii) LOD^pos-LOQ^neg if RLC were between the LOD and LOQ (43; 16.5%); and (iii) LOQ^pos if RLC were above the LOQ (144; 54.4%). Two-year overall survival of these three categories of patients was 75.4%, 79.8% and 66.4%, respectively (P=0.1197). Given their superimposable outcomes, the LOD^neg and LOD^pos-LOQ^neg categories were combined. Two-year overall survival of LOD^neg/LOD^pos-LOQ^neg patients was 77.0% versus 66.4% of LOQ^pos individuals (P=0.043). This figure was challenged in univariate analysis (P=0.046, hazard ratio=1.6, 95% confidence interval: 1.01-2.54) which confirmed the independent role of the LOD-LOQ approach in determining overall survival. In the AML1310 protocol, using the threshold of 0.035%, 2-year overall survival of patients with MRD <0.035% and MRD ≥0.035% was 74.5% versus 66.4%, respectively (P=0.3521). In conclusion, the use of the LOD-LOQ method results in more sensitive detection of MRD that, in turn, translates into a more accurate recognition of patients with different outcomes.