Hafnia alvei*

Hafnia alvei*
Respiratory Tract Isolates in a Community
Hospital Over a Three-Year Period and a Literature
Review
An Klapholz, M.D., F.C.C.P.; Klaus-Dieter Lessnau, M.D.;
Benson Huang, M.D.; Wilfredo Talavera, M.D., F.C.C.P.; and
John F. Boyle, Ph.D.
In a retrospective review, a group of seven patients
were found to have a sputum culture positive for
Hafnia alvei. Hafnia alvei is a Gram-negative enteric
and oropharyngeal bacillus and usually is
nonpathogenic. All our patients had a chronic underlying
illness and one of the patients was
endotracheally intubated at the time of the isolation
of this organism. Six of seven patients had other
H afnia alvei is a facultative Gram-negative enteric
bacillus belonging to the Enterobacteri-
aceae family. It is rarely considered a pathogenic
organism. Although one of the enteric flora, H alvei
can be a colonizer of the oropharynx and may be a
cause of pneumonia in the community or hospital
setting. It has been reported as a cause of pulmo-
nary infection in the literature in three patients.1’2
We describe a series of patients in whom H alvei
was isolated in respiratory secretions in both the
community and hospital environment and review
the most recent literature on this organism.
MATERIALS AND METHODS
We reviewed the medical records and chest radiographs of
seven patients who were found to have positive cultures of H
alvel in oropharyngeal or bronchial secretions. These patients
had been admitted to a Midtown Manhattan teaching hospital
from January 1989 to January 1992. Identification and sensitivity
testing was performed in our microbiology laboratory. Isolation
of the organism was performed on a trypticase soy agar plate
supplemented with 5 percent CO2 for 18 to 24 h following 24 h
of incubation at 35#{176}C (BBL Microbiology Systems, COC.
Keysville, Md). Isolates were tested on the MicroScan Gram-
negative MIC dry microdilution panel (MicroScan Division,
Baxter Healthcare Corp., West Sacramento, Cal) by using the
Autoscan-4 automated panel reader and computerized data
management system. Sensitivity testing included 33 commonly
used antibiotics. A computer-assisted review of the literature
was done by Medline and additional databases.
RESULTS
Seven patients were identified as having sputum
*From the Division of Pulmonary/Critical Care Medicine (Drs.
Klapholz, Lessnau, Huang, and Talavera), and the Department
of Clinical Microbiology (Dr. Boyle), Cabrini Medical Center,
New York; and New York Medical College (Drs. Klapholz and
Talavera), New York.
Manuscript received April 23, 1993; revision accepted July 20.
Reprint requests: Dr. Klapholz, Cabrini Medical Center, 227
East 19th Street, New York 10003
organisms isolated along with H alvei, and only one
patient had a pure growth of H alvei confirmed by
a culture obtained from a bronchoscopic protected
brush specimen. All isolates displayed resistance to
conventional antibiotics including cephalosporins
and penicillins. Although rare, H alvei may be a
potential pathogen in a patient with a chronic
underlying illness. (Chest 1994: 105 ;1098-1100)
cultures positive for H alvei as shown in Table 1.
There were 5 men and 2 women with a mean age
of 60 years. All the isolates were in patients with
a chronic underlying illness. Isolates from patients 1
to 4 were obtained within 48 h of admission and
therefore presumed to be community-acquired iso-
lates. The remaining patients were presumed to
have nosocomial colonization. In six patients, H
alvei was isolated with other pathogens, and there-
fore none of the pulmonary findings could be defi-
nitely attributed to H alvei alone. Clinical presenta-
tion and chest x-ray film findings on admission were
not helpful because of concomitant infectious and
noninfectious processes. For patient 7, fiberoptic
bronchoscopy was performed with a protected sheath
brush which on culture revealed pure colonies of H
alvei and confirmed the sputum culture of H alvei as
1098 Hafnia atval in a Community Hospital (Klapholz eta!)
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well.
Antibiotic sensitivities are summarized in Table 2.
Five isolates were resistant to ampicillin. Five of
seven isolates were resistant to a first-generation
cephalosporin, and four of seven isolates were resis-
tant to a second-generation cephalosporin. Two of
seven isolates were resistant to a semisynthetic
penicillin. All isolates were sensitive to the
aminoglycosides, imipenem-cilastin, and the
quinolones.
DISCUSSION
In the past, Hafnia was considered a member of
the genus Enterobacter and was called Enterobacter
hafnia or “paracolon” bacterium.3 With DNA and
biochemical studies, it has been defined as a sepa-
rate genus of the Kiebsiella family composed of
bacteria motile at 25#{176} to 36#{176}Cand immotile at higher
temperatures. Hafnia alvei is a small, plump bacillus

Age, yr/Ethnic Admitting Signs,
Patient Group, Sex* History Symptoms, and Hospital Course Sputum Chest X-ray Film
1 40/H/F Steroid-dependent
Table 1-Patients With Hafnia alvei in Respiratory Secretions
asthma, diabetes
mellitus, intravenous
drug use
2 83/W/M Myelodysplastic
syndrome, hyper-
tension
3 60/H/M Adenocarcinoma of
the lung; left-sided
hydropneumothorax,
recent chemo-
therapy
4 76/W/M COPD, arterioscle-
rotic heart disease,
atrial fibrillation,
Iupus anticoagulant
5 63/W/M Chronic renal failure,
idiopathic
thrombocytopenic
purpura
6 36/W/M Human immunodefi-
ciency virus positive
for 1 year
7 68/H/F COPD, congestive
*W=white; H=Hispanic.
heart failure,
chronic renal
failure,
hypothyroidism
Increasing dyspnea, expiratory
wheezing; treated initially with
steroids and bronchodilators
Hoarseness, fever, chills, leukocytosis;
laryngoscopy revealed mild glottic
edema responding to cefuroxime
within 3 d; steroids never adminis-
tered
Hemoptysis; fiberoptic bronchoscopy
revealed tumor with left lower lung
occlusion; remained afebrile, no
antibiotics given
Cough, dyspnea, minor hemoptysis;
cytologic studies revealed small cell
carcinoma; postobstructive
pneumonia improved symptomati-
cally
Cardiac arrest followed by hemicolec-
tomy because of colonic infarction
and perforated cecum; expired with
overwhelming pneumonia
Productive cough, fever, pleuritic
chest pain, normal leukocyte count;
treated with sulfamethoxazole/
trimethoprim for 14 d; discharged
afebrile
with a slight bipolar appearance on Gram staining.4
Rectal bleeding and urinary tract
infection; cardiopulmonary
It is catalase- and lysine decarboxylase-positive and
it does not hydrolyze arginine, thus differing from E
cloacae.5
Hafnia alvei has been associated with a wide array
of clinical infections. It has been reported as a cause
of meningitis,6 diarrhea,”7 necrotizing enterocolitis,8
pneumonia 1,2 urinary tract infection , endophthal-
mitis,9 and soft tissue infection.’0 In addition, Dibb”
reported that H alvei was the only Gram-negative
rod isolated from the outer ear canal in healthy
Norwegian individuals.
Washington et al’ reported the isolation of H alvei
from the respiratory tract in 5 patients from a total
of 760 isolates of Enterobacter over a 3-year period.
Three of the patients were described as having
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arrest, intubation; extubation,
but general condition worsened;
with aztreonam on clearing
radiographic infiltrates; expired
#1 H alvel, Streptococ-
cus pneumonia
Staphylococcus aureus
in blood and throat
culture; 1) S aureus,
Mycobacterlum
gordonae, Klebsiella
pneumonia, H alvel
1) H alvel,
Ac! netoba cter
hemolyticus
1) Citrobacter freundil;
5) Serratia
rnarcescens, M
gordonae; 6) H abet,
Escherichia cob!; 7)
Pseudom.onas
aeruginosa, S
Marcescens
(Bronchoalveolar
lavage); 14) H alvel
3) S aureus, P
aeruglnosa; 14) H
alvei
1) A hemolyticus,
Pneumocystis carinti,
Asperigillus species; 2)
H alvel
7) H alvel; had
fiberoptic
bronchoscopy with
protected sheath
specimen brush; pure
colonies of H abvei
No infiltrate
Minimal fibrotic
changes
Left lower lung
infiltrate
Left lower lung
infiltrate
Bilateral
infiltrates
Bilateral
infiltrates,
large left
upper lobe
bulla
Cardiomegaly,
left lower lung
infiltrate
chronic respiratory disease. Four of these isolates
were from sputum samples and one was from the
trachea, and all were nosocomially acquired. Three
isolates were considered commensals. Two isolates
(one from sputum and one tracheal isolate) were the
predominant organisms in two patients with fatal
bronchopneumonia, one of which also was isolated
from the lung postmortem. In addition, it was
shown to be an uncommon colonizer, isolated in 19
of 760 isolates of Enterobacter found in stool, urine,
the pharynx, oral ulcers, and wounds. As in our
series, H alvei was isolated in mixed cultures and
was a coisolate in 15 of those 19 isolates.
In addition, Frick et a12 reported a case of H alvei
pneumonia diagnosed by pure culture from a
bronchoscopic specimen in a patient receiving me-
CHEST/105/4/APRIL,1994 1099

Table 2-Antibiotic Sensitivities of Hafnia alvei Isolates
Patient Resistance to Cephalosporine Additional Resistance Sensitivity
1 None None All others, including ampicillin
2 Cephalothin, cefuroxime (medium-sensitive) Ampicillin, piperacillin All others
3 Cefazolin, cefuroxime, ceftazidime Ampicillin, piperacillin Ceftriaxone, aminoglycosides. cefotetan,
4 Cefazolin, cefuroxime, cefotetan Aztreonam Ampicillin, piperacillin, ciprofioxacin,
5 Cefazolin, cephalothin Ampicillin All others
1100 Hafnia atvei in a Community Hospital (K!aplsolz eta!)
aztreonam
aminoglycosides
6 Cephalothin, cefuroxime, ceftriaxone, Ampicillin Cefotetan, all others including
ceftazidime trimethoprim/sulfamethoxazole
7 None Ampicillin Aztreonam, all others
chanical ventilation for 12 days. Although it is
unclear from this report whether the specimen was
obtained via a protected brush or bronchoalveolar
lavage, the pure growth of H alvei strongly suggests
that this was the offending pathogen.
In our case series, H alvel was isolated from
sputum at the time of admission in four of the seven
cases (cases 1 to 3 and 6), suggesting that it is a
community colonizer. In all of those patients, it was
a coisolate with other organisms, and a clinical
response was obtained without specific treatment
for H alvei. Laboratory contamination was not sus-
pected because there was no clustering of these
isolates from a particular ward or over a specific
period of time. In addition, three of the four com-
munity isolates were in patients with underlying
pulmonary disease. Whether this predisposed those
patients to colonization as in the study of Washing-
ton et a18 is not known. Of the nosocomial isolates,
only patient 7 had a nosocomially acquired pneumo-
nia in which H alvei was the offending pathogen.
Although colony counts were not performed on the
sterile brush specimen, subsequent clinical and
radiographic improvement with an appropriate anti-
biotic strongly implied H abel as the offending
pathogen. Patient 4 had a nosocomially acquired
isolate without evidence of disease. In patient 6, H
alvel could have been a pathogen, but further
diagnostic studies were not done.
There was a pattern observed regarding the sen-
sitivity of these isolates, with the majority of them
resistant to ampicillin and some first- and second-
generation cephalosporins (Table 2). This pattern of
resistance is consistent with other case reports
reviewed in the literature.”2’8”2 Six of seven patients
had underlying chronic disease.
Although in the majority of our cases, there was
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no clinical importance in isolating H alvei other
than colonization, it may occasionally be the primary
cause of pneumonia. In the era of rapidly
evolving resistant organisms, immunosuppression
and prolonged ventilator management, one must be
wary of the emergence of H abel as a possible
pulmonary pathogen.
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