# MECHANISM OF BACTERIAL SUPERINFECTION

> **NIH NIH R01** · UNIVERSITY OF TEXAS HLTH SCIENCE CENTER · 1990 · $96,747

## Abstract

We propose to continue testing our original hypothesis that virus
infections alter the surfaces of host cells causing them to be
selectively susceptible to adherence of potentially pathogenic
bacteria.  We have selected Staphylococcus aureus and human
influenza A virus for continue study because staphylococcal
pneumonia is a well-documented example of a life-threatening
bacterial superinfection occurring in patients with complicated
influenza.  We propose to extend our previous studies, using a
simple cell culture model system, to a much more complex animal
model system.  We have selected to use ferrets (Mustela putorius
furo), which are small carnivores, because influenza in the ferret
most resembles the disease in humans.  One recent isolate of S.
aureus from a patient who died with post-influenza staphylococcal
pneumonia, and a human strain of influenza A/Hong Kong/1/68
(H3N2) virus are the primary infectious agents that will be used
throughout the in vivo study.  Influenza A virus-infection in
ferrets will be studied using different doses of the virus and
different routes of inoculation (intranasal, aerosol, and natural
transmission).  Virus-infected or sham-inoculated control ferrets
will be sacrificed at specific time intervals; blood, respiratory
washes, and respiratory tissues will be examined for virus
distribution patterns and infectivity, sialoprotein content of
mucin, the presence of nonspecific viral inhibitors, interferon
levels, seroconversion, and hematologic changes.  Staphylococcal
infection in ferrets will also be studied using different doses of
the bacteria and different routes of inoculation (intranasal,
aerosol, and the 'carrier state')  Respiratory tissues will be
harvested at various time intervals for quantitative culture to
determine the distribution and clearance of bacteria from
different sites in the tract.  The optimal conditions (dose, route of
inoculation, stage of virus infection) for inducing a combined
infection with influenza A virus and S. aureus will be determined,
and the morbidity and mortality rates will be compared with those
obtained with ferrets exposed to each agent alone.  Lastly, an in
vivo radioassay will be used to establish adherence patterns of
radiolabeled bacteria to mucosal surfaces in the respiratory tract,
and to determine the factors that affect adherence of bacteria to
these surfaces.

## Key facts

- **NIH application ID:** 3127044
- **Project number:** 5R01AI017242-09
- **Recipient organization:** UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
- **SAM.gov UEI:** C3KXNLTAAY98
- **Principal Investigator:** BARBARA A SANFORD
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $96,747
- **Award type:** 5
- **Project period:** 1980-08-01 → 1991-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3127044

## Citation

> US National Institutes of Health, RePORTER application 3127044, MECHANISM OF BACTERIAL SUPERINFECTION (5R01AI017242-09). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3127044. Licensed CC0.

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