Judith M. Holden

Bio: Judith M. Holden is an academic researcher from Harvard University. The author has contributed to research in topics: Streptococcus salivarius & Oroya. The author has an hindex of 3, co-authored 3 publications receiving 232 citations.

Bacteremia, fever, and splenomegaly caused by a newly recognized bartonella species.

Abstract: Bartonella species cause serious human infections globally, including bacillary angiomatosis, Oroya fever, trench fever, and endocarditis. We describe a patient who had fever and splenomegaly after traveling to Peru and also had bacteremia from an organism that resembled Bartonella bacilliformis, the causative agent of Oroya fever, which is endemic to Peru. However, genetic analyses revealed that this fastidious bacterium represented a previously uncultured and unnamed bartonella species, closely related to B. clarridgeiae and more distantly related to B. bacilliformis. We characterized this isolate, including its ability to cause fever and sustained bacteremia in a rhesus macaque. The route of infection and burden of human disease associated with this newly described pathogen are currently unknown.

Identification of Streptococcus bovis and Streptococcus salivarius in clinical laboratories.

Abstract: Streptococci identified as Streptococcus bovis, S. bovis variant, and Streptococcus salivarius were examined with respect to physiological and serological characteristics and cellular fatty acid content. Similarities in physiological reactions and problems encountered in serological analysis were noted, suggesting that an expanded battery of physiological tests is needed to definitively identify these streptococci. Cellular fatty acid analysis provided an accurate method for distinguishing S. salivarius from S. bovis and S. bovis variant.

Abdominal Abscesses Due to Actinomycosis after Laparoscopic Cholecystectomy: Case Reports and Review

Abstract: We describe 2 patients who presented to a health care facility with abdominal abscesses years after undergoing laparoscopic cholecystectomy that was complicated by gallstone spillage. In both patients, sample cultures yielded Actinomyces species and enteric organisms. In 1 patient, crystallographic analysis of abscess debris confirmed the presence of gallstones. Actinomyces species is a rare cause of abdominal abscesses that should be considered in this patient population.

What Happened to the Streptococci: Overview of Taxonomic and Nomenclature Changes

Abstract: Since the division of the Streptococcus genus into enterococci, lactococci, and streptococci in 1984, many changes in the nomenclature and taxonomy of the Streptococcus genus have taken place. The application of genetic comparisons has improved the proper classification of the different species. The Lancefield system of serogrouping the streptococci by the expression of beta-hemolysis on blood agar plates is still very useful for the identification of streptococci for patient management. The Lancefield grouping system cannot be used in itself for accurate identification of specific beta-hemolytic species, but it can be a useful part of the identification procedure. Except for identification of the “Streptococcus bovis group” of species and Streptococcus suis, Lancefield grouping is of little value in identification of the non-beta-hemolytic streptococci and related genera. In fact, identification of the non-beta-hemolytic species is problematic for conventional as well as commercially available identification procedures. A combination of conventional tests and specific chromogenic tests suggested by several investigators is presented and discussed. Tables are included that suggest tests and procedures to guide investigators attempting to identify all the species.

Detection of Zoonotic Pathogens and Characterization of Novel Viruses Carried by Commensal Rattus norvegicus in New York City

Abstract: Norway rats (Rattus norvegicus) are globally distributed and concentrate in urban environments, where they live and feed in closer proximity to human populations than most other mammals. Despite the potential role of rats as reservoirs of zoonotic diseases, the microbial diversity present in urban rat populations remains unexplored. In this study, we used targeted molecular assays to detect known bacterial, viral, and protozoan human pathogens and unbiased high-throughput sequencing to identify novel viruses related to agents of human disease in commensal Norway rats in New York City. We found that these rats are infected with bacterial pathogens known to cause acute or mild gastroenteritis in people, including atypical enteropathogenic Escherichia coli, Clostridium difficile, and Salmonella enterica, as well as infectious agents that have been associated with undifferentiated febrile illnesses, including Bartonella spp., Streptobacillus moniliformis, Leptospira interrogans, and Seoul hantavirus. We also identified a wide range of known and novel viruses from groups that contain important human pathogens, including sapoviruses, cardioviruses, kobuviruses, parechoviruses, rotaviruses, and hepaciviruses. The two novel hepaciviruses discovered in this study replicate in the liver of Norway rats and may have utility in establishing a small animal model of human hepatitis C virus infection. The results of this study demonstrate the diversity of microbes carried by commensal rodent species and highlight the need for improved pathogen surveillance and disease monitoring in urban environments. Importance: The observation that most emerging infectious diseases of humans originate in animal reservoirs has led to wide-scale microbial surveillance and discovery programs in wildlife, particularly in the developing world. Strikingly, less attention has been focused on commensal animals like rats, despite their abundance in urban centers and close proximity to human populations. To begin to explore the zoonotic disease risk posed by urban rat populations, we trapped and surveyed Norway rats collected in New York City over a 1-year period. This analysis revealed a striking diversity of known pathogens and novel viruses in our study population, including multiple agents associated with acute gastroenteritis or febrile illnesses in people. Our findings indicate that urban rats are reservoirs for a vast diversity of microbes that may affect human health and indicate a need for increased surveillance and awareness of the disease risks associated with urban rodent infestation.

Vector transmission of Bartonella species with emphasis on the potential for tick transmission.

Abstract: Bartonella species are gram-negative bacteria that infect erythrocytes, endothelial cells and macrophages, often leading to persistent blood-borne infections. Because of the ability of various Bartonella species to reside within erythrocytes of a diverse number of animal hosts, there is substantial opportunity for the potential uptake of these blood-borne bacteria by a variety of arthropod vectors that feed on animals and people. Five Bartonella species are transmitted by lice, fleas or sandflies. However, Bartonella DNA has been detected or Bartonella spp. have been cultured from numerous other arthropods. This review discusses Bartonella transmission by sandflies, lice and fleas, the potential for transmission by other vectors, and data supporting transmission by ticks. Polymerase chain reaction (PCR) or culture methods have been used to detect Bartonella in ticks, either questing or host-attached, throughout the world. Case studies and serological or molecular surveys involving humans, cats and canines provide indirect evidence supporting transmission of Bartonella species by ticks. Of potential clinical relevance, many studies have proposed co-transmission of Bartonella with other known tick-borne pathogens. Currently, critically important experimental transmission studies have not been performed for Bartonella transmission by many potential arthropod vectors, including ticks.

Classification and identification of the viridans streptococci.

Abstract: This review traces the history of the human, nonhemolytic, or viridans, streptococci and describes improvements in their taxonomy wrought by study of their biochemical profiles and analysis of their nucleic acids. The goal was to define species on the basis of genetic relationships and to describe these species by their phenotypic characteristics so that they can be easily identified. This method has resulted in the division of some species. Streptococcus mutans has been divided into four species, two of which are common in humans. Three more mutans group species are indigenous to animals. Conversely, S. constellatus, S. intermedius, and "S. milleri" have been combined under S. anginosus. S. mitis (or "S. mitior") can be well-defined and includes S. sanguis II. There is genetic heterogeneity within S. sanguis, but the species is usually easy to identify. There is also some heterogeneity in S. bovis, but most human isolates are genetically related. Discussions of the taxonomy of these species are accompanied by descriptions of the characteristics by which these streptococci can be identified. Among these species are potential pathogens which should be suspected in cases of endocarditis and purulent infections of liver, brain, and other tissues.

Actinomyces and Related Organisms in Human Infections

Abstract: Actinomyces israelii has long been recognized as a causative agent of actinomycosis. During the past 3 decades, a large number of novel Actinomyces species have been described. Their detection and identification in clinical microbiology laboratories and recognition as pathogens in clinical settings can be challenging. With the introduction of advanced molecular methods, knowledge about their clinical relevance is gradually increasing, and the spectrum of diseases associated with Actinomyces and Actinomyces-like organisms is widening accordingly; for example, Actinomyces meyeri, Actinomyces neuii, and Actinomyces turicensis as well as Actinotignum (formerly Actinobaculum) schaalii are emerging as important causes of specific infections at various body sites. In the present review, we have gathered this information to provide a comprehensive and microbiologically consistent overview of the significance of Actinomyces and some closely related taxa in human infections.