Immunohistochemical evidence of Clostridium sp, Staphylococcus aureus, and group A Streptococcus in severe soft tissue infections related to injection drug use

DETECTION OF SARS-COV-2 IN A SQUIRREL MONKEY (SAIMIRI SCIUREUS): A ONE HEALTH INVESTIGATION AND RESPONSE

Through collaborative efforts, One Health partners have responded to outbreaks of COVID-19 among animals, including those in human care at zoos. Zoos have been faced with numerous challenges, including the susceptibility of many mammalian species, and therefore the need to heighten biosecurity measures rapidly. Robust One Health collaborations already exist in Arizona to address endemic and emerging zoonoses, but these have rarely included zoos. The pandemic shed light on this, and Arizona subsequently expanded its SARS-CoV-2 surveillance efforts to include zoo animals. Testing and epidemiologic support was provided to expedite the detection of and response to zoonotic SARS-CoV-2 infection in zoo animals, as well as to understand possible transmission events. Resulting from this program, SARS-CoV-2 was detected from a rectal swab collected from an 8-yr-old squirrel monkey (Saimiri sciureus) from a zoo in Southern Arizona. The animal had rapidly become ill with nonrespiratory symptoms and died in July 2022. Genomic sequencing from the swab revealed mutations consistent with the Omicron (BA.2) lineage. An epidemiologic investigation identified an animal caretaker in close proximity to the affected squirrel monkey who tested positive for COVID-19 the same day the squirrel monkey died. Critical One Health partners provided support to the zoo through engagement of local, state, and federal agencies. Necropsy and pathologic evaluation showed significant necrotizing colitis; the overall clinical and histopathological findings did not implicate SARS-CoV-2 infection alone as a causal or contributing factor in the squirrel monkey's illness and death. This report documents the first identification of SARS-CoV-2 in a squirrel monkey and highlights a successful and timely One Health investigation conducted through multisectoral collaboration.

Blackleg: A Review of the Agent and Management of the Disease in Brazil

The genus Clostridium is an important group of pathogenic and nonpathogenic Gram-positive anaerobic bacteria with a sporulation capacity and wide distribution in different environments, including the gastrointestinal tracts of healthy and diseased animals and humans. Among the pathogenic species of the genus, Clostridium chauvoei stands out as a histotoxic agent. It causes significant myonecrosis such as blackleg, a disease with high lethality, especially in young cattle, and is responsible for significant livestock losses worldwide. The pathogenicity of the disease is complex and has not yet been fully elucidated. Current hypotheses cover processes from the initial absorption to the transport and deposition of the agent in the affected tissues. The virulence factors of C. chauvoei have been divided into somatic and flagellar antigens and soluble antigens/toxins, which are the main antigens used in vaccines against blackleg in Brazil and worldwide. This review provides important information on the first and current approaches to the agent C. chauvoei and its virulence factors as well as a compilation of data on Brazilian studies related to blackleg.

Immunohistochemical diagnosis of human infectious diseases: a review

BACKGROUND

Immunohistochemistry (IHC) using monoclonal and polyclonal antibodies is a useful diagnostic method for detecting pathogen antigens in fixed tissues, complementing the direct diagnosis of infectious diseases by PCR and culture on fresh tissues. It was first implemented in a seminal publication by Albert Coons in 1941.

MAIN BODY

Of 14,198 publications retrieved from the PubMed, Google, Google Scholar and Science Direct databases up to December 2021, 230 were selected for a review of IHC techniques, protocols and results. The methodological evolutions of IHC and its application to the diagnosis of infectious diseases, more specifically lice-borne diseases, sexually transmitted diseases and skin infections, were critically examined. A total of 59 different pathogens have been detected once in 22 different tissues and organs; and yet non-cultured, fastidious and intracellular pathogens accounted for the vast majority of pathogens detected by IHC. Auto-IHC, incorporating patient serum as the primary antibody, applied to diseased heart valves surgically collected from blood culture-negative endocarditis patients, detected unidentified Gram-positive cocci and microorganisms which were subsequently identified as Coxiella burnetii, Bartonella quintana, Bartonella henselae and Tropheryma whipplei. The application of IHC to ancient tissues dated between the ends of the Ptolemaic period to over 70 years ago, have also contributed to paleomicrobiology diagnoses.

CONCLUSION

IHC plays an important role in diagnostic of infectious diseases in tissue samples. Paleo-auto-IHC derived from auto-IHC, is under development for detecting non-identified pathogens from ancient specimens.

Immunohistochemistry in the diagnosis of cutaneous bacterial infections

The identification of pathogens is of vital importance for the adequate treatment of infections. During the past 2 decades, the approach to histopathologic diagnosis has been dramatically transformed by immunohistochemistry (IHC) specifically in the diagnosis and classification of tumors and more recently in the diagnosis of infectious diseases in tissue samples. The main goals of this article were to: (1) identify by IHC the cutaneous structures where bacterial pathogens are expressed in the course of infection, (2) identify the specific cells in which bacterial pathogens are expressed in positive cases, and (3) describe the pattern of distribution of the bacterial antigens within these cells (nuclear, cytoplasmatic, or membranous). This article is an up-to-date overview of the potential uses and limitations of IHC in the histopathologic diagnosis of cutaneous bacterial infections. In conclusion, IHC is especially useful in the identification of microorganisms that are present in low numbers, stain poorly, are fastidious to grow, culture is not possible, or exhibit an atypical morphology.

Transmission of methicillin-resistant Staphylococcus aureus infection through solid organ transplantation: confirmation via whole genome sequencing

We describe two cases of donor-derived methicillin-resistant Staphylococcus aureus (MRSA) bacteremia that developed after transplantation of organs from a common donor who died from acute MRSA endocarditis. Both recipients developed recurrent MRSA infection despite appropriate antibiotic therapy, and required prolonged hospitalization and hospital readmission. Comparison of S. aureus whole genome sequence of DNA extracted from fixed donor tissue and recipients' isolates confirmed donor-derived transmission. Current guidelines emphasize the risk posed by donors with bacteremia from multidrug-resistant organisms. This investigation suggests that, particularly in the setting of donor endocarditis, even a standard course of prophylactic antibiotics may not be sufficient to prevent donor-derived infection.

Molecular characterization of Staphylococcus aureus and influenza virus coinfections in patients with fatal Pneumonia

Molecular techniques were used to characterize genetic features of Staphylococcus aureus in 66 fatal cases of pneumonia caused by S. aureus and influenza A or B viruses. Nucleic acids were extracted from formalin-fixed, paraffin-embedded tissues. The majority of cases revealed genetic markers for Panton-Valentine leukocidin, mecA, and spa type t008.

Neutrophilic bacterial meningitis: pathology and etiologic diagnosis of fatal cases

The frequency of fatalities due to acute bacterial meningitis has decreased significantly due to vaccinations, early diagnoses, and treatments. We studied brain tissues of patients with fatal neutrophilic meningitis referred to the Centers for Disease Control for etiologic diagnosis from 2000-2009 to highlight aspects of the disease that may be preventable or treatable. Demographic, clinical, and laboratory data were extracted from records. Of 117 cases in the database with a diagnosis of meningitis or meningoencephalitis, 39 had neutrophilic inflammation in the meninges. Inflammatory cells infiltrated the superficial cortex in 16 of 39 (41%) cases. Bacteria were found using Gram and bacterial silver stains in 72% of cases, immunohistochemistry in 69% (including two cases where the meningococcus was found outside the meninges), and PCR in 74%. Streptococcus pneumoniae was the cause of the meningitis in 14 patients and Neisseria meningitidis in 9. In addition, Streptococcus spp. were found to be the cause in six cases, while Staphylococcus aureus, Staphylococcus spp., Enterococcus spp., and Fusobacterium were the cause of one case each. There were six cases in which no specific etiological agent could be determined. The mean age of the patients with S. pneumoniae was 39 years (range 0-65), with N. meningitidis was 19 years (range 7-51), whereas that for all others was 31 years (range 0-68). In summary, our study shows that S. pneumoniae continues to be the most frequent cause of fatal neutrophilic bacterial meningitis followed by N. meningitidis, both vaccine preventable diseases.

Rapid, simultaneous detection of Clostridium sordellii and Clostridium perfringens in archived tissues by a novel PCR-based microsphere assay: diagnostic implications for pregnancy-associated toxic shock syndrome cases

Clostridium sordellii and Clostridium perfringens are infrequent human pathogens; however, the case-fatality rates for the infections are very high, particularly in obstetric C. sordellii infections (>90%). Deaths from Clostridium sordellii and Clostridium perfringens toxic shock (CTS) are sudden, and diagnosis is often challenging. Formalin-fixed, paraffin-embedded (FFPE) tissues usually are the only specimens available for sudden fatal cases, and immunohistochemistry (IHC) for Clostridia is generally performed but it cannot identify species. A clear need exists for a rapid, species-specific diagnostic assay for FFPE tissues. We developed a duplex PCR-based microsphere assay for simultaneous detection of C. sordellii and C. perfringens and evaluated DNA extracted from 42 Clostridium isolates and FFPE tissues of 28 patients with toxic shock/endometritis (20 CTS, 8 non-CTS, as confirmed by PCR and sequencing). The microsphere assay correctly identified C. sordellii and C. perfringens in all known isolates and in all CTS patients (10 C. sordellii, 8 C. perfringens, 2 both) and showed 100% concordance with PCR and sequencing results. The microsphere assay is a rapid, specific, and cost-effective method for the diagnosis of CTS and offers the advantage of simultaneous testing for C. sordellii and C. perfringens in FFPE tissues using a limited amount of DNA.

Opioid drug abuse and modulation of immune function: consequences in the susceptibility to opportunistic infections

Infection rate among intravenous drug users (IDU) is higher than the general public, and is the major cause of morbidity and hospitalization in the IDU population. Epidemiologic studies provide data on increased prevalence of opportunistic bacterial infections such as TB and pneumonia, and viral infections such as HIV-1 and hepatitis in the IDU population. An important component in the intravenous drug abuse population and in patients receiving medically indicated chronic opioid treatment is opioid withdrawal. Data on bacterial virulence in the context of opioid withdrawal suggest that mice undergoing withdrawal had shortened survival and increased bacterial load in response to Salmonella infection. As the body of evidence in support of opioid dependency and its immunosuppressive effects is growing, it is imperative to understand the mechanisms by which opioids exert these effects and identify the populations at risk that would benefit the most from the interventions to counteract opioid immunosuppressive effects. Thus, it is important to refine the existing animal model to closely match human conditions and to cross-validate these findings through carefully controlled human studies. Better understanding of the mechanisms will facilitate the search for new therapeutic modalities to counteract adverse effects including increased infection rates. This review will summarize the effects of morphine on innate and adaptive immunity, identify the role of the mu opioid receptor in these functions and the signal transduction activated in the process. The role of opioid withdrawal in immunosuppression and the clinical relevance of these findings will also be discussed.

Intracellular persisting Staphylococcus aureus is the major pathogen in recurrent tonsillitis

Background

The two major indications for tonsillectomy are recurrent tonsillitis (RT) and peritonsillar abscess (PTA). Unlike PTAs, which are primarily treated surgically, RT is often cured by tonsillectomy only after a series of failed drug therapy attempts. Although the bacteriological background of RT has been studied, the reason for the lack of success of conservative therapeutic approaches is not well understood.

Methods

In a prospective study, tonsil specimens from 130 RT patients and 124 PTA patients were examined for the presence of extra- and intracellular bacteria using antibiotic protection assays. Staphylococcus aureus isolates from RT patients were characterized by pulsed-field gel electrophoresis (PFGE), spa-typing and MSCRAMM-gene-PCR. Their ability for biofilm formation was tested and their cell invasiveness was confirmed by a flow cytometric invasion assay (FACS), fluorescent in situ hybridization (FISH) and immunohistochemistry.

Findings

S. aureus was the predominant species (57.7%) in RT patients, whereas Streptococcus pyogenes was most prevalent (20.2%) in PTA patients. Three different assays (FACS, FISH, antibiotic protection assay) showed that nearly all RT-associated S. aureus strains were located inside tonsillar cells. Correspondingly, the results of the MSCRAMM-gene-PCRs confirmed that 87% of these S. aureus isolates were invasive strains and not mere colonizers. Based upon PFGE analyses of genomic DNA and on spa-gene typing the vast majority of the S. aureus isolates belonged to different clonal lineages.

Conclusions

Our results demonstrate that intracellular residing S. aureus is the most common cause of RT and indicate that S. aureus uses this location to survive the effects of antibiotics and the host immune response. A German translation of the Abstract is provided as supplementary material (Abstract S1).

Fatal Plasmodium falciparum, Clostridium perfringens, and Candida spp. Coinfections in a Traveler to Haiti

Malaria is one of the most common causes of febrile illness in travelers. Coinfections with bacterial, viral, and fungal pathogens may not be suspected unless a patient fails to respond to malaria treatment. Using novel immunohistochemical and molecular techniques, Plasmodium falciparum, Clostridium perfringens, and Candida spp. coinfections were confirmed in a German traveler to Haiti. Plasmodium falciparum-induced ischemia may have increased this patient's susceptibility to C. perfringens and disseminated candidiasis leading to his death. When a patient presents with P. falciparum and shock and is unresponsive to malaria treatment, secondary infections should be suspected to initiate appropriate treatment.

Adrenal gland hemorrhage in patients with fatal bacterial infections

A wide spectrum of adrenal gland pathology is seen during bacterial infections. Hemorrhage is particularly associated with meningococcemia, while abscesses have been described with several neonatal infections. We studied adrenal gland histopathology of 65 patients with bacterial infections documented in a variety of tissues by using immunohistochemistry. The infections diagnosed included Neisseria meningitidies, group A streptococcus, Rickettsia rickettsii, Streptococcus pneumoniae, Staphylococcus aureus, Ehrlichia sp., Bacillus anthracis, Leptospira sp., Clostridium sp., Klebsiella sp., Legionella sp., Yersinia pestis, and Treponema pallidum. Bacteria were detected in the adrenal of 40 (61%) cases. Adrenal hemorrhage was present in 39 (60%) cases. Bacteria or bacterial antigens were observed in 31 (79%) of the cases with adrenal hemorrhage including 14 with N. meningitidis, four with R. rickettsii, four with S. pneumoniae, three with group A streptococcus, two with S. aureus, two with B. anthracis, one with T. pallidum, and one with Legionella sp. Bacterial antigens were observed in nine of 26 non-hemorrhagic adrenal glands that showed inflammatory foci (four cases), edema (two cases), congestion (two cases), or necrosis (one case). Hemorrhage is the most frequent adrenal gland pathology observed in fatal bacterial infections. Bacteria and bacterial antigens are frequently seen in adrenal glands with hemorrhage and may play a pathogenic role. Although N. meningitidis is the most frequent bacteria associated with adrenal gland pathology, a broad collection of bacteria can also cause adrenal lesions.

Clostridium difficile-associated diarrhea: an emerging threat to pregnant women

OBJECTIVE

To estimate if Clostridium difficile-associated disease (CDAD) is increasing in peripartum women.

STUDY DESIGN

Peripartum CDAD was assessed through 1) passive surveillance collecting clinical and pathology data on severe cases and 2) survey among infectious disease consultants (ICDs) in the Emerging Infections Network.

RESULTS

Ten severe cases were collected; most had associated antibiotic use. Seven women were either admitted to the ICU or underwent colectomy. Three infants were stillborn, and 3 women died. The epidemic Clostridium difficile strain was found in 2 cases. Among 798 ICDs, 419 (52%) participated in the survey. Thirty-seven respondents (9%) recalled 55 cases, mostly in the postpartum period with 21 complications, mainly due to relapse.

CONCLUSION

Severe CDAD may be increasing in peripartum women. Clinicians should have a low threshold for testing, be aware of the potential for severe outcomes, and take steps to reduce both the risk of disease and resultant complications.

Application of immunohistochemistry to infections

CONTEXT

Pathologists play an important role in the diagnosis or exclusion of infectious diseases. Traditionally, the diagnosis of infectious diseases rely on serologic assays and cultures. Serologic results may be difficult to interpret in the setting of immunosuppression, fresh tissue is not always available for culture, and culture of fastidious pathogens can be difficult and may take weeks or months to yield a result. Although some microorganisms or their cytopathic effects may be readily identifiable on routine and/or histochemical stains, often these changes are not specific or are sparse in the sample evaluated. In these cases, additional immunohistochemical stains are often needed to establish the diagnosis of infection.

OBJECTIVE

To review the current value and limitations of the use of immunohistochemistry in the diagnosis of infectious diseases in formalin-fixed tissue samples.

DATA SOURCES

Literature in Medline and the authors' own experience.

CONCLUSIONS

Immunohistochemistry has proven to be a useful tool in the diagnosis of infectious diseases in tissue samples. Immunohistochemistry is especially useful in the identification of microorganisms that are present in low numbers, stain poorly, are fastidious to grow, are noncultivable, or exhibit an atypical morphology. Finally, it is important to remember that there may be widespread occurrence of common antigens among bacteria and pathogenic fungi and both monoclonal and polyclonal antibodies must be tested for possible cross-reactivity with other organisms.

Histochemical identification of methicillin-resistant Staphylococcus aureus: contribution to preventing nosocomial infection

Histopathological diagnosis of bacterial infection remains a technical challenge. Application of histochemistry provides a prospect of the improvement of diagnostic quality. Methicillin-resistant Staphylococcus aureus (MRSA), the most common drug-resistant bacterium, is of clinical importance in making appropriate histopathological diagnosis. Recently, community-acquired MRSA has expanded, in addition to conventional hospital-acquired MRSA. Immunohistochemical identification of MRSA requires antibodies against both species-specific antigens and penicillin-binding protein 2' (PBP2'), whereas a species-specific gene and mec A encoding PBP2' can be the target of in situ hybridization (ISH) detection. Specificity verification in histochemistry should be emphasized, since S. aureus commonly expresses protein A in the cell wall, whose immunoglobulin-binding capacity is retrieved by heating pretreatment of routinely prepared sections. The ISH technique for MRSA needs meticulous pretreatment of routine paraffin-embedded sections and signal enhancement sequence. This review focuses on such histopathological approaches, which should have profound potential for contributing to decreasing and preventing nosocomial infection of MRSA.

Toxic shock associated with Clostridium sordellii and Clostridium perfringens after medical and spontaneous abortion

OBJECTIVE

To better understand the risk of fatal toxic shock caused by Clostridium sordellii in women who had a recent medical abortion with mifepristone and misoprostol.

METHODS

We performed active and passive surveillance for cases of toxic shock associated with medical or spontaneous abortion. To identify the cause of toxic shock, immunohistochemical assays for multiple bacteria were performed on formalin-fixed surgical and autopsy tissues. We extracted DNA from tissues, performed Clostridium species-specific polymerase chain reaction assays, and sequenced amplified products for confirmation of Clostridium species.

RESULTS

We report four patients with toxic shock associated with Clostridium species infection after medical or spontaneous abortion. Two women had fatal Clostridium perfringens infections after medically induced abortions: one with laminaria and misoprostol and one with the regimen of mifepristone and misoprostol. One woman had a nonfatal Clostridium sordellii infection after spontaneous abortion. Another woman had a fatal C sordellii infection after abortion with mifepristone and misoprostol. All four patients had a rapidly progressive illness with necrotizing endomyometritis.

CONCLUSION

Toxic shock after abortion can be caused by C perfringens as well as C sordellii, can be nonfatal, and can occur after spontaneous abortion and abortion induced by medical regimens other than mifepristone and misoprostol.

LEVEL OF EVIDENCE

III.

Fatal multiorgan failure due to yellow fever vaccine-associated viscerotropic disease

Yellow fever vaccine-associated viscerotropic disease (YEL-AVD) is a rare complication of yellow fever (YF) vaccination. A previously healthy 22-year-old female died following YF vaccination despite aggressive measures. Serial viral load titers, cytokine levels and host genetic factors were evaluated in an attempt to understand this unusual and lethal outcome. The patient's high-titer vaccine viremia and possibly related minor genetic anomalies provide clues to exploring the etiology of YEL-AVD.

Why some injection drug users lick their needles: a preliminary survey

BACKGROUND

Injection drug users (IDUs) with poor hygiene practices are at risk for infection with their commensal flora. One example of a poor hygiene practice is licking the needle prior to injecting the drug. There are few published reports addressing the proportion of IDUs who lick their needles prior to injection and no prior studies evaluating the reasons for this practice.

METHODS

We conducted face-to-face interviews with 40 IDUs admitted to the internal medicine service at our institution. We collected data regarding whether the subject licked the needle before injecting drugs, whether the subject licked the injection site before or after injecting drugs, and the reasons they report for doing so.

RESULTS

Thirteen (32.5%, 95% CI, 18.6-49.1) of 40 subjects reported licking their needles prior to injecting. Reasons included ritualistic practices, cleaning the needle, enjoying the taste of the drug, checking the "quality" of the drug, and checking that the needle was in usable condition.

CONCLUSIONS

In our study, approximately one-third of IDUs licked their needles prior to injecting. More data are needed to demonstrate whether the practice of needle licking significantly increases a person's risk for infection with oropharyngeal flora. Medical providers should ask patients about specific practices surrounding injection drug use, and educate drug users about avoiding unhygienic injection practices.