Coccidioides Species: A Review of Basic Research: 2022.

Coccidioides immitis and posadasii are closely related fungal species that cause coccidioidomycosis. These dimorphic organisms cause disease in immunocompetent as well as immunocompromised individuals and as much as 40% of the population is infected in the endemic area. Although most infections resolve spontaneously, the infection can be prolonged and, in some instances, fatal. Coccidioides has been studied for more than 100 years and many aspects of the organism and the disease it causes have been investigated. There are over 500 manuscripts concerning Coccidioides (excluding clinical articles) referenced in PubMed over the past 50 years, so there is a large body of evidence to review. We reviewed the most accurate and informative basic research studies of these fungi including some seminal older studies as well as an extensive review of current research. This is an attempt to gather the most important basic research studies about this fungus into one publication. To focus this review, we will discuss the mycology of the organism exclusively rather than the studies of the host response or clinical studies. We hope that this review will be a useful resource to those interested in Coccidioides and coccidioidomycosis.

Utility of DNA sequencing for direct identification of invasive fungi from fresh and formalin-fixed specimens.

OBJECTIVES: To describe and discuss the utility and potential pitfalls of ribosomal RNA locus sequencing for direct identification of invasive fungi from fresh and formalin-fixed, paraffin-embedded specimens. METHODS: DNA was extracted from fresh and formalin-fixed, paraffin-embedded tissue and subjected to real-time polymerase chain reaction (PCR) targeting ITS2 and D2 regions of fungal ribosomal RNA locus. Cycle sequencing was performed on PCR products, and the identity of sequences was determined using a public database. RESULTS: Four clinical cases of invasive fungal infection are presented to illustrate the utility of DNA sequencing for determining etiology when microbiological culture is negative, for shortening the time to identification of slow-growing fungi, for guiding antifungal therapy, and for shedding light on the pathogenesis of disseminated fungal infection. CONCLUSIONS: Fungal ribosomal RNA locus sequencing from fresh or formalin-fixed, paraffin-embedded specimens is a powerful tool for rapid and accurate diagnosis of patients with culture-negative or uncultured invasive mycosis.

Ceftobiprole: a new cephalosporin for the treatment of skin and skin structure infections.

Ceftobiprole is among the first of a new generation of cephalosporins with activity against aerobic Gram-negative bacilli, which extends to cefepime-sensitive Pseudomonas aeruginosa, and activity against Gram-positive organisms, which includes methicillin-resistant Staphylococcus aureus. Ceftobiprole is currently undergoing evaluation by the US FDA for the treatment of complicated skin and skin structure infections, with a decision pending further evaluation of study site monitoring. It is also being evaluated for the treatment of community-acquired and healthcare-associated pneumonia. Two Phase III multicenter trials have demonstrated noninferiority in complicated skin and skin structure infections when tested against vancomycin in primarily Gram-positive bacterial infections, and when tested against vancomycin plus ceftazidime in Gram-positive and Gram-negative bacterial infections. It is well tolerated, with the most common side effects being nausea and dysgeusia. Ceftobiprole is likely to prove useful as an empiric as well as directed monotherapy in patients with complicated skin and skin structure infections, in which both Gram-positive pathogens including methicillin-resistant S. aureus and Gram-negative pathogens including cefepime-sensitive P. aeruginosa may be involved.

Expert opinion: what to do when there is Coccidioides exposure in a laboratory.

Inadvertent exposure to Coccidioides species by laboratory staff and others as a result of a mishap is not an uncommon cause of infection in clinical microbiology laboratories. These types of infection may occur in laboratories outside the endemic areas, because the etiologic agent is unexpected in the submitted specimens and because personnel may be unfamiliar with the hazards of dealing with Coccidioides species in the laboratory. Coccidioidal infections are often difficult to treat, and outcomes can be poor. Here, we emphasize prevention and an approach to a laboratory accident that minimizes the risk of exposure to laboratory staff and staff in adjacent areas. On the basis of an artificially large exposure to arthroconidia that may occur as a result of a laboratory accident, a conservative approach of close observation and early treatment of exposed staff is discussed.

Management of infections due to KPC-producing Klebsiella pneumoniae.

The emergence of the Klebsiella pneumoniae carbapenemases in K. pneumoniae and other Gram-negative bacteria, usually on a background of multidrug resistance, has led to difficult therapeutic choices. Among available antibiotics, tigecycline and the polymyxins are the most frequently active against these organisms in vitro. Optimal therapy of infections due to these bacteria may involve maximization of antibiotic dose as well as their use in combination.

The efficacy and safety of ceftobiprole in the treatment of complicated skin and skin structure infections: evidence from 2 clinical trials.

Complicated skin and skin structure infections (cSSSIs) are common and are associated with significant health and economic costs. These infections are predominantly characterized by infection with Staphylococcus aureus, and SENTRY Surveillance data indicate that the occurrence of this pathogen in cSSSIs has increased and that almost half of the isolated pathogens are methicillin-resistant S. aureus (MRSA). Surveillance data also indicate that Gram-negative isolates are not uncommon in cSSSIs. In the past, empiric antimicrobial coverage of both Gram-positive and Gram-negative infections has generally necessitated the use of at least 2 antimicrobial agents. Ceftobiprole, a novel advanced-generation pyrrolidinone cephalosporin, is currently under review by the Food and Drug Administration as therapy for cSSSIs. This article presents a summary of the results of 2 recently published multicenter noninferiority trials involving approximately 1600 patients with a variety of cSSSIs. In the 1st trial, which included patients with Gram-positive cSSSI, the clinical cure rate at the test-of-cure (TOC) visit (the primary end point) among patients receiving ceftobiprole was 93.3%. The 2nd trial included a broad range of cSSSIs of varying pathogenicity. In this trial, the clinical cure rate among patients receiving ceftobiprole for S. aureus and MRSA infection was 94.6% and 91.8%, respectively. Ceftobiprole's capacity as a broad-spectrum agent was demonstrated in the 2nd trial, in which the clinical cure rate at TOC was 90.5% against a variety of infections and pathogens (including Gram negatives). In addition, the cure rate among patients with moderate to severe diabetic foot infection who received ceftobiprole was 86.2%, and these patients experienced a shorter length of stay in the hospital than those who received a comparator. This article also addresses the results of these trials in the context of the current medical need for safe broad-spectrum antimicrobial agents with MRSA coverage.

Caspofungin.

Caspofungin, the first inhibitor of fungal beta-1,3 glucan synthesis to receive approval by the United States Food and Drug Administration, is effective for the treatment of mucosal and invasive candidiasis and invasive aspergillosis. It is also active in vitro and in animal models against a number of other filamentous and dimorphic endemic fungi and in animal models of Pneumocystis carinii infection. In vitro studies and some animal studies almost always indicate an absence of antagonism when caspofungin is combined with azole or polyene antifungal agents. Caspofungin has an excellent safety profile. Caspofungin may prove to be useful in empirical therapy for suspected invasive fungal infections. Additional clinical trial data that expand our knowledge of the usefulness of caspofungin for these and other mycoses, including its administration in combination with other antifungal agents, is anticipated. Caspofungin is an important addition to the antifungal pharmacopoeia.

Safety and immunogenicity of hepatitis A vaccine in human immunodeficiency virus-infected patients: a double-blind, randomized, placebo-controlled trial.

The safety and immunogenicity of inactivated hepatitis A (HepA) vaccine was assessed in 133 hepatitis A virus-seronegative, human immunodeficiency virus (HIV)-infected adults. Patients were randomly assigned to receive, in a blinded fashion, either 2 doses of vaccine (1440 enzyme-linked immunosorbent assay units) or placebo 6 months apart. Seroconversion at month 9 was observed in 68% of those with CD4 cell counts >/=200 cells/mm(3) but in only 9% of those with lower CD4 cell counts (P=.004). HepA vaccine was well tolerated and had no effect on the course of HIV infection or plasma HIV RNA load.