Development of microbiological field methodology for water and food-chain hygiene analysis of Campylobacter spp. and Yersinia spp. in Burkina Faso,West Africa

Field-adaptable research methods for identifying Campylobacter sp., Yersinia sp. and other pathogenic and indicator bacteria were designed in Finland and tested in Burkina Faso. Several bacterial groups were also validated from artificially contaminated samples. Campylobacter strains were cultivated using an innovative gas generation system: The ‘Portable Microbe Enrichment Unit’ (PMEU) which provides microaerobic gas flow into the enrichment broth. This enhanced cultivation system produced rapid growth of several isolates of campylobacteria from water and chicken samples. The latter were obtained from local marketplace samples. No yersinias were found in the field studies, whereas they were readily recovered from the spiked samples, as well as Salmonella sp. and Escherichia coli strains. The PMEU method turned out to be reliable for monitoring of water and food hygiene in remote locations.     

临床细菌检验与预防医院感染

随着现代医学技术的发展,医疗活动中侵入性操作越来越多,如动静脉插管、泌尿系导管、气管插管、吸入装置、监控仪器探头等,给病人的临床诊治带来了便利.然而,侵入性操作在诊治疾病的同时,把外界的微生物带入体内,同时损伤了机体的防御屏障,使病原体容易侵入机体,不可避免地造成医院感染,对患者和医护工作人员的身体健康造成影响.因此医院感染中病原微生物的临床检验对病原菌的诊断监测以及抗菌药物的使用具有重要的意义,临床细菌检验对预防治疗医院感染十分必要.     

Impact of a hand hygiene educational programme on hospital-acquired infections in medical wards

Improvement in hand hygiene (HH) compliance has been associated with a decrease in the incidence of hospital-acquired infection (HAI) and hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) infection/colonization. We aimed to evaluate the impact of a multimodal intervention in medical wards on HH compliance, alcohol-based hand rub (AHR) consumption and incidence of HAI and HA-MRSA. A before-after intervention study and an assessment 1 year later were conducted in three internal medicine wards. HH compliance during routine patient care was monitored using the WHO HH observation method. AHR consumption was registered. HAI incidence was actively sought during the PRE and POST periods. HAI risk factors were prospectively recorded and incidence density was calculated. A total of 825 patients were prospectively followed in the PRE period and 868 patients in the POST period. We observed 1531 opportunities for HH in PRE and POST periods and 450 1 year later. HH compliance improved from 54.3% to 75.8% (p 0.005) and remained 75.8% at follow-up. AHR consumption increased from 10.5 to 27.2 L/1000 hospital-days and 31.5 L/1000 hospital-days at follow-up. Incidence density of HAI was 6.93 and 6.96/1000 hospital-days in the PRE and POST intervention periods, respectively. HA-MRSA incidence density was 0.92 in the PRE period vs. 0.25/1000 hospital-days in the POST period (p 0.2) and 0.15/1000 hospital-days (p 0.1) 1 year later. A sustained increase in AHR consumption was followed by an improvement in HH compliance after a multimodal campaign. A trend for lower incidence density of new hospital-acquired MRSA was detected in the POST intervention and follow-up periods.     

Critical factors in the translation of improved antimicrobial strategies for medical implants and devices

Biomaterials-associated infection incidence represents an increasing clinical challenge as more people gain access to medical device technologies worldwide and microbial resistance to current approaches mounts. Few reported antimicrobial approaches to implanted biomaterials ever get commercialized for physician use and patient benefit. This is not for lack of ideas since many thousands of claims to new approaches to antimicrobial efficacy are reported. Lack of translation of reported ideas into medical products approved for use, results from conflicting goals and purposes between the various participants involved in conception, validation, development, commercialization, safety and regulatory oversight, insurance reimbursement, and legal aspects of medical device innovation. The scientific causes, problems and impressive costs of the limiting clinical options for combating biomaterials-associated infection are well recognized. Demands for improved antimicrobial technologies constantly appear. Yet, the actual human, ethical and social costs and consequences of their occurrence are less articulated. Here, we describe several clinical cases of biomaterials-associated infections to illustrate the often-missing human elements of these infections. We identify the current societal forces at play in translating antimicrobial research concepts into clinical implant use and their often-orthogonal constituencies, missions and policies. We assert that in the current complex environment between researchers, funding agencies, physicians, patients, providers, producers, payers, regulatory agencies and litigators, opportunities for translatable successes are minimized under the various risks assumed in the translation process. This argues for an alternative approach to more effectively introduce new biomaterials and device technologies that can address the clinical issues by providing patients and medical practitioners new options for desperate clinical conditions ineffectively addressed by biomedical innovation.     

The revival of colistin: an old antibiotic for the 21st century

Background

Multidrug resistant Gram-negative rods are emerging as major pathogens and are the cause of difficulty to treat infections. In certain situations colistin is the only active drug.

Methods

A retrospective review of the patient's charts admitted at Hôtel-Dieu de France hospital, Beirut, between October 2002 and February 2004 and treated with intravenous colistin.

Results

Fifteen patients were identified; they were suffering from urinary tract infections, cellulitis, osteomyelitis, mediastinitis and intra-abdominal abscess. The microorganisms were resistant to all available antibiotics except colistin. Three strains were also susceptible to aminoglycosides. Pseudomonas aeruginosa was the most frequently isolated pathogen. Colistin was used in monotherapy in 12 patients and combined with amikacin in three patients. At the end of therapy, a 93% rate of favorable clinical outcome was observed. Renal toxicity was encountered among 12 patients. It was severe in only two cases in which creatinin clearance decline surpassed 50% of the baseline value. No neurological toxicity was observed.

Conclusion

Colistin has an important role to play when used for the treatment of infections with multiresistant Gram-negative bacteria. Nephrotoxicity seems much lower than expected and neurotoxicity is minimal.     

Healthcare-associated versus community-acquired infections: A new challenge for science and society

Healthcare and community associated MRSA are meanwhile exchanged in all directions between hospitals, long-term care facilities, nursing homes, and the community. This article is focusing on the situation concerning MRSA, but the situation concerning other multidrug-resistant (MDR) pathogens such as vancomycin-resistant enterococci or MDR Gram-negative pathogens is similar. Some European countries have started national campaigns to improve the situation significantly. They require the successful cooperation between healthcare facilities, public health authorities, health insurances, quality management and patient safety organizations, educational facilities, the public, and the veterinarian sector. These activities in the society need scientific data to provide evidence for the intervention measures and support their implementation. To really support the activities in the society, intervention studies are urgently needed to provide a more robust basis for decisions to improve the situation.     

Extended-spectrum beta-lactamase-producing Escherichia coli infections in children: Are community-acquired strains different from nosocomial strains?

Infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli are an important cause of morbidity and mortality, especially in children. We compared 58 epidemiologically unrelated ESBL-producing E. coli strains that caused infections. They were isolated between 2008 and 2012 in two Parisian pediatric hospitals and grouped according to their origin into either community-acquired (CA) (n = 37) or nosocomially acquired (NA) (n = 21) strains. Molecular characteristics of the ESBLs, phylogenetic traits of the strains including their belonging to clone O25b-ST131, prevalence of associated virulence genes, growth capacities in different media, metabolic phenotype and biofilm formation abilities were studied. ESBL type, associated resistance and distribution of phylogenetic groups were similar in the CA and NA groups. More than 60% of the B2 phylogroup strains in both groups belonged to the ST131 clone. Interestingly, CA strains possessed more genes encoding virulence factors and the distribution of these genes differed significantly between the two groups: fyuA, hlyC, papC and papGII were more frequent in the CA group, whereas iroN was more frequent in the NA group. CA strains also showed enhanced growth capacities in Luria Bertani rich medium. They tended to produce more biofilm but the difference was not significant. This study confirms the wide spread of clone ST131 among infected children, regardless of whether their infections were community- or nosocomially acquired. It highlights genotypic and phenotypic differences according to the origin of the strains that could indicate adaptability of these multi-resistant bacteria to specific environmental and host factors.     

Stenotrophomonas isolates in a tertiary care centre in South India

PurposeStenotrophomonas maltophilia is an emerging multi-drug resistant pathogen increasingly isolated in India. This study aimed to identify patients from whom Stenotrophomonas maltophilia had been isolated and assess predictors of mortality in this population.MethodsThis was a retrospective cohort study of hospitalized patients with a positive culture for S. maltophilia over a 3-year period. Clinical details and laboratory results were assessed from hospital records. Bivariate and multivariate analysis was used to identify risk factors for mortality.ResultsOne hundred and nineteen patients (mean age 48.6 years) were included in the study. Of these, 111 patients were hospitalized for at least 48 ?hours prior to culture and 98 were admitted in the intensive care unit. Bivariate analysis revealed multiple associations with mortality, including a background of renal, cardiac, autoimmune disease, recent carbapenam use and COVID-19 infection and increasing ventilatory requirement, lower PaO₂/FiO₂ (P/F) ratio, vasopressor use, thrombocytopenia, and hypoalbuminemia at the time of positive isolate. Multivariate analysis showed that autoimmune disease [OR 27.38; 95% CI (1.39–540)], a P/F ratio of less than 300 [OR 7.58; 95% CI (1.52–37.9)], vasopressor requirement [OR 39.50; 95% CI (5.49–284)] and thrombocytopenia [OR 11.5; 95% CI (2.04–65.0)] were statistically significantly associated with increased mortality, while recent surgery and receipt of antibiotics [OR 0.16; 95% CI (0.03–0.8)] targeted against S. maltophilia were associated with decreased mortality.ConclusionStenotrophomonas maltophilia is primarily isolated in patients in the intensive care unit. In our study the need for vasopressors, autoimmune disease, lower P/F ratios and thrombocytopenia were associated with higher mortality. The association of targeted antibiotics with reduced mortality suggests that the pathogenic role of S. maltophilia should not be underestimated. This finding needs to be confirmed with larger, prospective studies.     

New patterns of methicillin-resistant Staphylococcus aureus (MRSA) clones,community-associated MRSA genotypes behave like healthcare-associated MRSA genotypes within hospitals,Argentina

Methicillin-resistant Staphylococcus aureus (MRSA) burden is increasing worldwide in hospitals [healthcare-associated (HA)-MRSA] and in communities [community-associated (CA)-MRSA]. However, the impact of CA-MRSA within hospitals remains limited, particularly in Latin America. A countrywide representative survey of S. aureus infections was performed in Argentina by analyzing 591 clinical isolates from 66 hospitals in a prospective cross-sectional, multicenter study (Nov-2009). This work involved healthcare-onset infections-(HAHO, >48 hospitalization hours) and community-onset (CO) infections [including both, infections (HACO) in patients with healthcare-associated risk-factors (HRFs) and infections (CACO) in those without HRFs]. MRSA strains were genetically typed as CA-MRSA and HA-MRSA genotypes (CA-MRSA_G and HA-MRSA_G) by SCCmec- and spa-typing, PFGE, MLST and virulence genes profile by PCR. Considering all isolates, 63% were from CO-infections and 55% were MRSA [39% CA-MRSA_G and 16% HA-MRSA_G]. A significantly higher MRSA proportion among CO- than HAHO-S. aureus infections was detected (58% vs 49%); mainly in children (62% vs 43%). The CA-MRSA_G/HA-MRSA_G have accounted for 16%/33% of HAHO-, 39%/13% of HACO- and 60.5%/0% of CACO-infections. Regarding the epidemiological associations identified in multivariate models for patients with healthcare-onset CA-MRSA_G infections, CA-MRSA_G behave like HA-MRSA_G within hospitals but children were the highest risk group for healthcare-onset CA-MRSA_G infections. Most CA-MRSA_G belonged to two major clones: PFGE-type N-ST30-SCCmecIVc-t019-PVL⁺ and PFGE-type I-ST5-IV-SCCmecIVa-t311-PVL⁺ (45% each). The ST5-IV-PVL⁺/ST30-IV-PVL⁺ clones have caused 31%/33% of all infections, 20%/4% of HAHO-, 43%/23% of HACO- and 35%/60% of CACO- infections, with significant differences by age groups (children/adults) and geographical regions. Importantly, an isolate belonging to USA300-0114-(ST8-SCCmecIVa-spat008-PVL⁺-ACME⁺) was detected for the first time in Argentina. Most of HA-MRSA_G (66%) were related to the Cordobes/Chilean clone-(PFGE-type A-ST5-SCCmecI-t149) causing 18% of all infections (47% of HAHO- and 13% of HACO-infections).Results strongly suggest that the CA-MRSA clone ST5-IV-PVL⁺ has begun to spread within hospitals, replacing the traditional Cordobes/Chilean-HA-MRSA clone ST5-I-PVL⁻, mainly in children. Importantly, a growing MRSA reservoir in the community was associated with spreading of two CA-MRSA clones: ST5-IV-PVL⁺, mainly in children with HRFs, and ST30-IV-PVL⁺ in adults without HRFs. This is the first nationwide study in Argentina providing information about the molecular and clinical epidemiology of CA-MRSA, particularly within hospitals, which is essential for designing effective control measures in this country and worldwide.     

老年恶性肿瘤患者医院感染的危险因素分析

医院感染是恶性肿瘤患者最严重且常见的并发症之一,老年恶性肿瘤患者由于其年龄特点更易发生医院感染。住院时间、放化疗的损伤、侵入性操作、营养不良以及合并基础疾病等因素均导致老年恶性肿瘤患者易发生医院感染。本文就老年恶性肿瘤患者医院感染的危险因素展开分析并作一综述。     

Continuous monitoring of lactate during exercise in humans using subcutaneous and transcutaneous microdialysis

We have evaluated the possibility of monitoring the plasma lactate concentration in human volunteers during cycle ergometer exercise using subcutaneous and transcutaneous microdialysis. In transcutaneous microdialysis, the relative increase in dialysate lactate concentration exceeded that of plasma lactate concentration by a factor of 6 during exercise due to exercise-induced lactate secretion in sweat. During exercise the subcutaneous microdialysis dialysate lactate concentration underestimated the plasma lactate concentration possibly due to diffusion limitation or adipose tissue lactate production. While it was demonstrated that microdialysis can be used for on-line lactate monitoring, neither subcutaneous nor transcutaneous dialysate lactate concentration were linearly related to the plasma lactate concentration during exercise, and it was found therefore that it was not possible to monitor directly plasma lactate concentration during exercise.     

Infections caused by Aeromonas species in hospitalized patients: A case series

The Aeromonads are ubiquitous Gram-negative bacilli that cause community acquired, and healthcare associated infections. In this retrospective study we analysed clinical and microbiological characteristics of thirty-six culture proven Aeromonas infections. The most common species isolated was A.hydrophila. Clinical presentation included syndromes like skin and soft tissue infections (SSTI), urinary tract infections, and central line associated bloodstream infections (CLABSI). Most of the isolates were sensitive to aminoglycosides [97.2%], followed by 3 rd generation cephalosporins, quinolones and carbapenems. Overall mortality was 13.88% (5 out of 36 patients). A high index of suspicion is required for diagnosis and better outcomes.