Paleogenomic insights into the red complex bacteria Tannerella forsythia in Pre-Hispanic and Colonial individuals from Mexico

The 'red complex' is an aggregate of three oral bacteria (Tannerella forsythia, Porphyromonas gingivalis and Treponema denticola) responsible for severe clinical manifestation of periodontal disease. Here, we report the first direct evidence of ancient T.forsythia DNA in dentin and dental calculus samples from archaeological skeletal remains that span from the Pre-Hispanic to the Colonial period in Mexico. We recovered twelve partial ancient T. forsythia genomes and observed a distinct phylogenetic placement of samples, suggesting that the strains present in Pre-Hispanic individuals likely arrived with the first human migrations to the Americas and that new strains were introduced with the arrival of European and African populations in the sixteenth century. We also identified instances of the differential presence of genes between periods in the T. forsythia ancient genomes, with certain genes present in Pre-Hispanic individuals and absent in Colonial individuals, and vice versa. This study highlights the potential for studying ancient T. forsythia genomes to unveil past social interactions through analysis of disease transmission. Our results illustrate the long-standing relationship between this oral pathogen and its human host, while also unveiling key evidence to understand its evolutionary history in Pre-Hispanic and Colonial Mexico. This article is part of the theme issue 'Insights into health and disease from ancient biomolecules'.

Capnocytophaga canimorsus Capsular Serovar and Disease Severity, Helsinki Hospital District, Finland, 2000-2017

We assembled a collection of 73 Capnocytophaga canimorsus isolates obtained from blood cultures taken from patients treated at Helsinki University Hospital (Helsinki, Finland) during 2000–2017. We serotyped these isolates by PCR and Western blot and attempted to correlate pathogen serovar with patient characteristics. Our analyses showed, in agreement with previous research, that 3 C. canimorsus serovars (A–C) caused most (91.8%) human infections, despite constituting only 7.6% of isolates found in dogs. The 3 fatalities that occurred in our cohort were equally represented by these serovars. We found 2 untypeable isolates, which we designated serovars J and K. We did not detect an association between serovar and disease severity, immune status, alcohol abuse, or smoking status, but dog bites occurred more frequently among patients infected with non-A–C serovars. Future research is needed to confirm serovar virulence and develop strategies to reduce risk for these infections in humans.

Incidence of Cronobacter spp. infections, United States, 2003-2009

During 2003-2009, we identified 544 cases of Cronobacter spp. infection from 6 US states. The highest percentage of invasive infections occurred among children <5 years of age; urine isolates predominated among adults. Rates of invasive infections among infants approximate earlier estimates. Overall incidence of 0.66 cases/100,000 population was higher than anticipated.

Community-onset Gram-negative Surveillance Program annual report, 2012

The Australian Group on Antimicrobial Resistance performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric Gram-negative pathogens. The 2012 survey focussed on community-onset infections, examining isolates from urinary tract infections from patients presenting to outpatient clinics, emergency departments or to community practitioners. In 2012, 2,025 Escherichia coli, 538 Klebsiella species and 239 Enterobacter species were tested using a commercial automated method (Vitek 2, BioMérieux) and results were analysed using Clinical and Laboratory Standards Institute breakpoints from January 2012. Of the key resistances, non-susceptibility to the third-generation cephalosporin, ceftriaxone, was found in 4.2% of E. coli and 4.6%-6.9% of Klebsiella spp. Non-susceptibility rates to ciprofloxacin were 6.9% for E. coli, 0.0%-3.5% for Klebsiella spp. and 0.8%-1.9% in Enterobacter spp, and resistance rates to piperacillin-tazobactam were 1.7%, 0.7%-9.2%, and 8.8%-11.4% for the same 3 groups respectively. Only 1 Enterobacter cloacae was shown to harbour a carbapenemase (IMP-4).

Hospital-onset Gram-negative Surveillance Program annual report, 2011

The Australian Group on Antimicrobial Resistance performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric Gram-negative pathogens. The 2011 survey focussed on hospital-onset infections, examining isolates from all specimens presumed to be causing disease. In 2011, 1,827 Escherichia coli, 537 Klebsiella species and 269 Enterobacter species were tested using a commercial automated method (Vitek 2, BioMérieux) and results were analysed using Clinical and Laboratory Standards Institute breakpoints from January 2012. Of the key resistances, non-susceptibilty to the third-generation cephalosporin, ceftriaxone, was found in 9.6% of E. coli and 9.5%-12.1% of Klebsiella spp. Non-susceptibility rates to ciprofloxacin were 10.6% for E. coli, 0.0%-8.3% for Klebsiella spp. and 0.0%-5.0% in Enterobacter spp. Resistance rates to gentamicin were 8.6%, 2.9%-10.9%, and 0.0%-15.6% for the same 3 groups respectively. Eight strains, 5 Klebsiella spp. and 3 Enterobacter spp. were shown to harbour a carbapenemase (IMP-4).

Australian Group on Antimicrobial Resistance Community-onset Gram-negative Surveillance Program annual report, 2010

The Australian Group on Antimicrobial Resistance (AGAR) performs regular period-prevalence studies to monitor changes in antimicrobial resistance in selected enteric Gram-negative pathogens. The 2010 survey focussed on community-onset infections, examining isolates from urinary tract infections from patients presenting to outpatient clinics, emergency departments or to community practitioners. Two thousand and ninety-two Escherichia coli, 578 Klebsiella species and 268 Enterobacter species were tested using a commercial automated method (Vitek 2, BioMérieux) and results were analysed using Clinical and Laboratory Standards Institute breakpoints from January 2012. Of the key resistances, non-susceptibility to the third-generation cephalosporin, ceftriaxone, was found in 3.2% of E. coli and 3.2%-4.0% of Klebsiella spp. Non-susceptibility rates to ciprofloxacin were 5.4% for E. coli, 1.0%-2.3% for Klebsiella spp., and 2.5%-6.6% in Enterobacter spp, and resistance rates to piperacillin-tazobactam were 2.8%, 3.2%-6.9%, and 16.8%-18.0% for the same 3 groups respectively. Only 3 strains, 2 Klebsiella spp. and 1 Enterobacter spp, were shown to harbour a carbapenemase (IMP-4).

Introduction of new technology into critical care practice: a history of HA-1A human monoclonal antibody against endotoxin

OBJECTIVES

HA-1A, a monoclonal antibody against endotoxin, was thought to be effective in treating patients with Gram-negative sepsis. Because of this possibility, many clinicians felt obligated to use the drug and assumed that its product license application would be approved by the U.S. Food and Drug Administration (FDA). Nevertheless, the efficacy of HA-1A was not conclusively demonstrated by a first clinical trial. The FDA rejected the product license application and requested a second clinical trial, which was suspended after excess mortality was noted in patients treated with HA-1A. This review of the history of the drug was prepared to provide clinicians and sepsis investigators with information about HA-1A and, by extension, the process by which new technology is introduced into critical care practice.

DATA SOURCES

Data used to prepare this review were obtained from the author's personal files as well as the computerized MEDLINE database.

STUDY SELECTION

Studies were selected for their relevance to the history of HA-1A and their relevance to the introduction of potentially useful medical technology.

DATA EXTRACTION

The author extracted all applicable data.

DATA SYNTHESIS

Although the first clinical trial of HA-1A suggested that the drug was effective in treating patients with Gram-negative bacteremia with or without shock, further analysis by the FDA indicated a benefit only for bacteremic patients with shock. Furthermore, the original study design was not followed, leading in part to the FDA's refusal of the product license application. Concern also was raised over the issue of identifying which patients should receive HA-1A and the cost of the drug, which would have put it past the reach of some American hospitals and thereby, would have conflicted with the ethical principle of social justice. Finally, the second trial suggested that HA-1A might be harmful.

CONCLUSIONS

Due to the FDA's action, the issues raised about HA-1A, and the results of the two clinical trials, clinicians should not use the drug. The history of HA-1A provides insights about how new technology is and will be introduced into critical care practice.

History of recognition and measurement of colonization resistance of the digestive tract as an introduction to selective gastrointestinal decontamination

Selective decontamination of the digestive tract was developed following the observation that the digestive tract normally has considerable resistance to colonization by newly ingested bacteria. The research that eventually led to selective decontamination was performed because in the late 1960s and early 1970s, the need for prophylaxis against Gram-negative infections in immuno-compromized patients became evident. At that time, the relatively small number of antibiotics available for therapy of serious infections often lead to treatment failure. To introduce the subject of selective decontamination, this paper, therefore, starts with a short historical overview of the kind of infectious agents as well as the antibiotics available in the 1960s; particularly regarding the type and treatment of infections in severely compromised patients. The fact that the possibilities in infectious diseases were limited was the reason for our experimental search for ways of successful prophylactic treatment with minimal risk of development of resistance.

Changing flora in burn and trauma units: historical perspective--experience in the United States

Changes in patient management, increased survival rates, and widespread use of antimicrobials have altered the flora that are found to colonize the wounds of patients with burns and trauma-related injuries. Enterococci have emerged as a prominent cause of wound infection and are capable of producing significant morbidity. Staphylococcus aureus, although it remains a common colonizer, has developed resistance to several antimicrobial agents. Recent reports suggest that the incidence of Pseudomonas infections is decreasing, whereas multiple antimicrobial resistance has emerged in a number of other gram-negative organisms that were not heretofore considered major pathogens. Candida organisms appear to be the prominent pathogens among opportunistic yeasts and fungi, and Bacteroides and Clostridium species appear to be the most common causes of infection by anaerobes. Patterns of viral infection in patients with burns and trauma-related injuries have not been investigated in detail. Overall, it appears that rates of infection and associated mortality have decreased in some patient populations; progress in this regard can be attributed to improvements in antimicrobial therapy, would management, and nutrition.