Natural contamination of human hands with enteric parasites in Indian Subcontinent

AIM: To investigate the prevalence of enteric parasite contamination on hands and the potential role naturally contaminated hands may have in their transmission.

METHODS: Prior to initiating the survey, the protocol was reviewed and approved by respective Institutional Review Boards of each survey site (Dhaka, Bangladesh and Kolkata, India). Both stool and corresponding hand wash samples collected, were analyzed for the presence of enteric parasitic ova/(oo)cysts employing conventional microscopy coupled with permanent staining techniques. Additionally molecular approaches such as polymerase chain reaction (PCR) of enteric parasites recovered from both stool and corresponding hand wash samples, were also used to further confirm their identity.

RESULTS: A total of 972 stool samples were collected from both sites surveyed (300 volunteers from Kolkata, India and 672 from Dhaka, Bangladesh). Parasitic analysis revealed, 113 (38%) from Kolkata, India and 267 (40%) of stool samples from Dhaka, Bangladesh were positive for parasitic ova/(oo)cysts. When the corresponding hand wash samples were analyzed, 43 (14%) stool-positive volunteers in Kolkata, India and 47 (7%) in Dhaka, Bangladesh were positive for enteric parasitic ova/(oo)cysts. Ascaris lumbricoides (A. lumbricoides) ova and Giardia lamblia (G. lamblia) cysts predominated in hands wash samples from both sites surveyed (from India, A. lumbricoides ova, 53%; G. lamblia cysts 31% and from Bangladesh, A. lumbricoides ova, 47%; G. lamblia cysts 19%). Genotypic analysis of enteric parasitic ova/(oo)cysts obtained from both stool and corresponding hand wash samples taken from the same person were found to be identical.

CONCLUSION: These results suggest a possible role of hands contaminated with enteric parasites’ ova/(oo)cysts in the transmission of these parasites highlighting another role of hand hygiene/proper hand washing in reducing the disease burden in low socioeconomic communities.

Liver biopsy for visceral leishmaniasis diagnosis in pregnancy: report of 2 cases

Visceral leishmaniasis (VL) or kala-azar is a zoonosis caused by intracellular protozoa of the Leishmania genus and is transmitted to humans by the bite of phlebotomine sandflies. It particularly affects cells in the phagocytic mononuclear system, accompanied by disturbances of cellular and humoral immunity. VL is potentially fatal and is characterized by fever, hepatosplenomegaly, diarrhea, epistaxis, jaundice, anemia, leucopenia, thrombocytopenia, hypoalbuminemia and hyperglobulinemia. Diagnostic suspicion is based on epidemiological, clinical and laboratory data and is confirmed by detecting the parasite in infected tissue. Splenic aspiration is the most sensitive method, followed by bone marrow aspiration (BMA) by sternal puncture, liver biopsy and lymph node aspiration; but, due to safety concerns, BMA is the most recommended method. VL is included as a target disease by players in drug research and development. Severe liver dysfunction associated with VL is uncommon. We report two VL cases in pregnant women from Bauru, Sao Paulo state, Brazil, considered an endemic area. The first of them developed hepatic failure due to fulminant hepatitis. In both cases, BMA was unable to find the protozoan; thus, liver biopsy was the only means of making the diagnosis.

Extended role for insertion sequence elements in the antibiotic resistance of Bacteroides

The Bacteroides species are important micro-organisms, both in the normal physiology of the intestines and as frequent opportunistic anaerobic pathogens, with a deeply-rooted phylogenetic origin endowing them with some interesting biological features. Their prevalence in anaerobic clinical specimens is around 60%-80%, and they display the most numerous and highest rates of antibiotic resistance among all pathogenic anaerobes. In these antibiotic resistance mechanisms there is a noteworthy role for the insertion sequence (IS) elements, which are usually regarded as representatives of ‘selfish’ genes; the IS elements of Bacteroides are usually capable of up-regulating the antibiotic resistance genes. These include the cepA (penicillin and cephalosporin), cfxA (cephamycin), cfiA (carbapenem), nim (metronidazole) and ermF (clindamycin) resistance genes. This is achieved by outward-oriented promoter sequences on the ISs. Although some representatives are well characterized, e.g., the resistance gene-IS element pairs in certain resistant strains, open questions remain in this field concerning a better understanding of the molecular biology of the antibiotic resistance mechanisms of Bacteroides, which will have clinical implications.

Human immunodeficiency virus, atherosclerosis and Chlamydophila pneumoniae

Chlamydophila pneumoniae (C. pneumoniae) is an obligate, intracellular bacterium associated with a wide variety of acute and chronic diseases. C. pneumoniae infection is characterized by persistence and immunopathological damage to host target tissues, including the lung. Over the past 20 years, a variety of studies have investigated a possible link between C. pneumoniae infection and atherosclerosis, because of its role in all stages of atherosclerosis, from initial inflammatory lesions to plaque rupture. In the current highly active antiretroviral therapy (HAART) era, many human immunodeficiency virus (HIV)-infected patients are experiencing health problems that accompany the aging process, mainly the risk of cardiovascular disease (CVD). There is renewed interest in a link between atherosclerotic CVD and as yet poorly defined environmental exposures, including infectious agents. On the one hand, the patient with HIV and lipodystrophy caused by HAART and exacerbated by C. pneumoniae infection could be a factor of risk for atherosclerosis. An assessment of the therapy against C. pneumoniae and HAART should always be conducted. It is advisable that HIV-acquired immune deficiency syndrome patients undergo a serological test to determine exposure to C. pneumoniae and to assess treatment options. On the other hand, in patients with a positive serology to C. pneumoniae, an increment of the body mass index has been found; therefore, it is probable that the recurrent infection may play an important role in creating adverse endothelial conditions allowing the infection by C. pneumoniae in its chronic form, to damage the endothelial surface. Vascular studies would be necessary for corroboration.

Transcribing virulence in Staphylococcus aureus

Staphylococcus aureus (S. aureus) is an important human pathogen capable of causing a diverse range of infections. Once regarded as an opportunistic pathogen causing primarily nosocomial infections, recent years have seen the emergence of S. aureus strains capable of causing serious infection even in otherwise healthy human hosts. There has been much debate about whether this transition is a function of unique genotypic characteristics or differences in the expression of conserved virulence factors, but irrespective of this debate it is clear that the ability of S. aureus to cause infection in all of its diverse forms is heavily influenced by its ability to modulate gene expression in response to changing conditions within the human host. Indeed, the S. aureus genome encodes more than 100 transcriptional regulators that modulate the production of virulence factors either directly via interactions with cis elements associated with genes encoding virulence factors or indirectly through their complex interactions with each other. The goal of this review is to summarize recent work describing these regulators and their contribution to defining S. aureus as a human pathogen.

Fighting nosocomial infections with biocidal non-intrusive hard and soft surfaces

Approximately 7 million people worldwide acquire a healthcare associated infection each year. Despite aggressive monitoring, hand washing campaigns and other infection control measures, nosocomial infections (NI) rates, especially those caused by antibiotic resistant pathogens, are unacceptably high worldwide. Additional ways to fight these infections need to be developed. A potential overlooked and neglected source of nosocomial pathogens are those found in non-intrusive soft and hard surfaces located in clinical settings. Soft surfaces, such as patient pyjamas and beddings, can be an excellent substrate for bacterial and fungal growth under appropriate temperature and humidity conditions as those present between patients and the bed. Bed making in hospitals releases large quantities of microorganisms into the air, which contaminate the immediate and non-immediate surroundings. Microbes can survive on hard surfaces, such as metal trays, bed rails and door knobs, for very prolonged periods of time. Thus soft and hard surfaces that are in direct or indirect contact with the patients can serve as a source of nosocomial pathogens. Recently it has been demonstrated that copper surfaces and copper oxide containing textiles have potent intrinsic biocidal properties. This manuscript reviews the recent laboratory and clinical studies, which demonstrate that biocidal surfaces made of copper or containing copper can reduce the microbiological burden and the NI rates.

Pharmacodynamics for predicting therapeutic outcome and countering resistance spread: The cefditoren case

The relationship between pharmacokinetics and pharmacodynamics is a key instrument to improve antimicrobial stewardship and should be aimed to identification of the drug exposure measure that is closely associated not only with the ability to kill organisms but also to suppress the emergence of resistant subpopulations. This article reviews published studies for efficacy prediction with cefditoren and those aimed to explore its potential for countering resistance spread, focusing on the three most prevalent community-acquired isolates from respiratory infections: Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae (H. influenzae) and Streptococcus pyogenes (S. pyogenes). Studies for efficacy prediction include in vitro pharmacodynamic simulations (using physiological concentrations of human albumin) and mice models (taking advantage of the same protein binding rate in mice and humans) to determine the value of the pharmacodynamic indices predicting efficacy, and Monte Carlo simulations to explore population pharmacodynamic coverage, as weapons for establishing breakpoints. Studies exploring the potential of cefditoren (free concentrations obtained with 400 mg cefditoren bid administration) for countering spread of resistance showed its capability for countering (1) intra-strain spread of resistance linked to ftsI gene mutations in H. influenzae; (2) the spread of H. influenzae resistant strains (with ftsI gene mutations) in multi-strain H. influenzae niches or of S. pneumoniae strains with multiple resistance traits in multi-strain S. pneumoniae niches; and (3) for overcoming indirect pathogenicity linked to β-lactamase production by H. influenzae that protects S. pyogenes in multibacterial niches. This revision evidences the ecological potential for cefditoren (countering resistance spread among human-adapted commensals) and its adequate pharmacodynamic coverage of respiratory pathogens (including those resistant to previous oral compounds) producing community-acquired infections.

Pathogenesis of Chagas disease cardiomyopathy

Chagas disease, or American trypanosomiasis, is a parasitic infection caused by the flagellate protozoan Trypanosoma cruzi. Chagas disease is mainly affecting rural populations in Mexico and Central and South America. The World Health Organization estimates that 300 000 new cases of Chagas disease occur every year and approximately 20 000 deaths are attributable to Chagas. However, this organisation classified Chagas disease as a neglected tropical disease. The economic burden of this disease is significant. In many Latin American countries, the direct and indirect costs, including the cost of health care in dollars and loss of productivity, attributable to Chagas disease ranges from $40 million to in excess of $800 million per nation per annum. So, it remains a contemporary public health concern. In chronic phase, mortality is primarily due to the rhythm disturbances and congestive heart failure that result from the chronic inflammatory cardiomyopathy (CCC) due to the persistence presence of parasites in the heart tissue. Mechanisms underlying differential progression to CCC are still incompletely understood. In the last decades immunological proteomic genetic approaches lead to significant results which help to disperse the veil covering the knowledge of the pathogenic process. Here, we reported these significant progresses.

Medical errors, infection-control breaches and the use of adulterated and misbranded medical devices

Several well-publicized cases of improper cleaning, disinfection or sterilization of contaminated reusable medical equipment that posed an increased risk of patient-to-patient disease transmission were reported within the past few years, resulting in the notification of approximately 20 000 patients. These medical errors, the specific infection-control standards they breached, and assessments of the risk of infection associated with each are discussed. Other topics discussed include the Food and Drug Administration’s (FDA) regulation of medical devices and infection-control products; the use of adulterated, misbranded, and investigational devices; consent decrees and associated Certificates of Medical Necessity; and informed patient consent. Focus is placed on liquid chemical sterilization, its history, and the FDA’s recent censure and discontinuation of a medical device labeled with this claim, namely, the STERIS System 1 processor. Recommendations are provided for healthcare facilities, regulatory agencies, manufacturers of reusable medical devices, and professional healthcare organizations and administrations to improve public health and prevent healthcare-associated infections.

Current situation of Giardia infection in Spain: Implications for public health

Giardia is an enteric protozoan that infects a wide range of vertebrate hosts, being considered a major causative agent of gastrointestinal disease in humans in both developing and developed countries. Giardia infection has also a significant impact on livestock health, causing diarrhoea and resulting in significant economic lost. Transmission is either direct, through the faecal-oral route, or indirect, through ingestion of contaminated water or food. In this article, we review current knowledge about the epidemiology of giardiasis in different populations in Spain, including humans, livestock, companion animals, and wildlife. Environmental contamination of surface waters and raw foods by Giardia cysts is also addressed. Special relevance has been given to the data available on the molecular characterization of the Giardia isolates obtained from clinical and environmental samples, as determining the species/assemblages and subassemblages involved is essential for accurately identifying the parasite and assessing zoonotic transmission. The public health significance of these findings has also been thoroughly discussed.

Regulation of fim genes in uropathogenic Escherichia coli

Uropathogenic Escherichia coli (UPEC) is the leading cause of urinary tract infections in women, causing significant morbidity and mortality in this population. Adherence to host epithelial cells is a pivotal step in the pathogenesis of UPEC. One of the most important virulence factors involved in mediating this attachment is the type 1 pilus (type 1 fimbria) encoded by a set of fim genes arranged in an operon. The expression of type 1 pili is controlled by a phenomenon known as phase variation, which reversibly switches between the expression of type 1 pili (Phase-ON) and loss of expression (Phase-OFF). Phase-ON cells have the promoter for the fimA structural gene on an invertible DNA element called fimS, which lines up to allow transcription, whereas transcription of the structural gene is silenced in Phase-OFF cells. The orientation of the fimS invertible element is controlled by two site-specific recombinases, FimB and FimE. Environmental conditions cause transcriptional and post-transcriptional changes in UPEC cells that affect the level of regulatory proteins, which in turn play vital roles in modulating this phase switching ability. The role of fim gene regulation in UPEC pathogenesis will be discussed.

What is the purpose of launching the World Journal of Clinical Infectious Diseases?

Launching of the World Journal of Clinical Infectious Diseases (WJCID) could have been possible due to efforts of the publisher, members of the editorial board, all the authors and definitely our readers. I congratulate everyone for making it possible. Pathogenic organisms of various origin cause infectious diseases often resulting in symptomatic illness. WJCID is an open access peer reviewed journal that will be published bimonthly. WJCID will primarily emphasize on topics relevant to infections affecting human and animal health yet articles from other diseases and relevant issues will also be encouraged. WJCID welcomes articles from either basic or applied research in different disciplines like Epidemiology of communicable and non-communicable infections, Immunology and Genetics. WJCID covers topics like Host-Parasites interactions, Vector biology, development of advanced tools for diagnosis, genetic susceptibility to diseases, and disease prevention and vector control. WJCID will work as an important resource of basic and applied research in the field of infections. It is widely recommended that clinical implementations of basic and applied research be encouraged for the benefit to each stream. So again I welcome everyone and assure that WJCID will be a great platform where you can feel free to share your valuable results, discuss new hypothesis and research problems and update yourself with the most recent advancements made in the field of infections.

Antibiotic-resistant bugs in the 21st century: A public health challenge

Antimicrobial resistance, which has been reported against almost every antibiotic discovered, is one of the most urgent public health problems, threatening to undermine the effectiveness of infectious disease treatment worldwide. Since penicillin ushered in the antibiotic era in the mid 20th century, the scientific world had engaged in a war between the development of antibacterial agents and bacterial resistance. During the first decade of the 21st century, grave concern has been expressed over the evolution of multi-drug resistant staphylococci, enterococci, and mycobacteria, which pose serious clinical and public health challenge to humans. The present picture is frighteningly similar to the pre-antibiotic era, with reports of nosocomial spread and intercontinental dissemination of multi-drug resistant bacteria. For infected patients, there is no magic bullet. The microbial pathogens appear to be gaining the upper hand, coupled with a recent dramatic reduction in antibiotic research by pharmaceutical companies because of the high cost of drug research. Several compounds that have recently been developed or resurrected to treat gram-positive infections are still unable to meet the armamentarium of resistance mechanisms of these pathogens. The situation is worse for gram-negative organisms, where no new drug is currently being developed against them. A multi-disciplinary approach to combat resistance is required, which must be applied, sustained, and continuously refined. The key components for maintaining effective antimicrobial chemotherapy will include better use of existing agents, coupled with continuous investment in new and innovative technologies, which must include diagnostics and vaccines in addition to new antimicrobial agents.

Statins as antifungal agents

Fungal infections are increasing and their treatment is difficult, because the most widely used antifungal drugs are relatively toxic and have serious side effects. Therefore, interest has focused on safely applicable and clinically introduced non-antifungal drugs, which have potent antifungal activity. Statins were originally used as cholesterol lowering agents in human therapy, but recent studies demonstrated their in vitro antifungal activity against yeasts and filamentous fungi. This indicated their potential application, alone or in combination with other drugs, in the treatment of such diseases. Their effective concentrations are higher than their maximum achievable serum levels; therefore, the application of statins for the treatment of invasive fungal infections is only possible in combination with antifungal agents. These synergistic combinations establish a basis for a new safely applicable therapy. This review focuses on the antifungal activity of statins alone and in combination with antifungal and non-antifungal drugs, and their possible application in clinical therapy.