Pediatric Infection Due to Multiresistant Salmonella enterica Serotype Infantis in Honduras

Abstract

We report the case of a pediatric patient with a Salmonella enterica serotype Infantis infection. Detailed microbiological investigation revealed that this isolate carries four ␤-lactamase genes (bla TEM-1b variant, bla SHV-5 , bla CTX-M-15 , and bla CMY-2 ) conferring resistance to all ␤-lactams but imipenem. This is the first report of a Salmonella isolate with CTX-M and AmpC enzymes on the American continent, the first report of bla CMY-2 in Salmonella serotype Infantis, and the first report of bla CTX-M-15 in the genus Salmonella. CASE REPORTIn August 2002, an 18-month-old infant male with a clinical syndrome indicating an enteritis-like infection was admitted to the Santa Teresa Hospital in Comaguaya (Honduras). The patient, whose symptoms began 3 days before admission, presented with a fever up to 40°C, mucous bloody diarrhea, nausea, and vomiting. His urine was cloudy, with a pH of 5, and laboratory analysis showed elevated numbers of red blood cells (4/field), white blood cells (6/field), and granular casts (6/field). Laboratory analysis of fecal samples revealed the presence of erythrocytes (4/field) and neutrophils (15/field). Because of limited resources available at the hospital, no microbiological techniques were performed on these samples. An empirical treatment without a confirmatory microbiological diagnosis was immediately initiated with intravenous amikacin (50 mg every 12 h) and intravenous ceftriaxone (350 mg every 12 h) and continued for 9 days. Oral anti-inflammatory drugs (acetaminophen) to control pain and fever were also administered, and the patient was rehydrated intravenously as required. The condition of the patient improved (fever decreased to normal temperature values, and vomiting and diarrhea ceased), and he was discharged from the hospital. Two weeks later, the patient returned with a relapse of the symptoms and severe malnutrition. A second empirical treatment consisting of intravenous amikacin (40 mg every 12 h) and cefoxitin (250 mg every 6 h) was administered for 9 days. At the time of the second admission, urine and stool samples were collected and sent to the Laboratorio Central de Microbiologia in Tegucigalpa, Honduras, for microbiological analysis. Both samples were confirmed, by following standard methods, as positive for the isolation of Salmonella sp. (preenrichment of the sample in tetrathionate broth, followed by plating on Taylor's xylose lysine deoxycholate agar). The laboratory values for the hemogram were 3.18 million red blood cells/mm 3 , 8,800 white blood cells/mm 3 , 2,200 lymphocytes/mm 3 , 165,000 platelets/mm 3 , a hematocrit of 21.9%, a hemoglobin concentration of 7.6 g/dl, a mean corpuscular hemoglobin level of 23.9 pg, a mean corpuscular hemoglobin concentration of 34.7 g/dl, and a mean corpuscular volume of 69 fl. All of these values were consistent with a loss of blood and reflected the presence of anemia in the patient. Screening for human immunodeficiency virus by enzymelinked immunosorbent assay was negative. The isolates were tested for antimicro...

Longitudinal Farm Study of Extended-Spectrum β-Lactamase-Mediated Resistance

“…The isolates obtained in November 2004 were also tested by bla TEM PCR with primers TEM-F (5Ј-ATT CTT GAA GAC GAA AGG GC-3Ј) and TEM-R (5Ј-ACG CTC AGT GGA ACG AAA AC-3Ј), and the amplicons generated were sequenced as described previously (13).…”

Nosocomial Outbreak of Pediatric Gastroenteritis Caused by CTX-M-14-Type Extended-Spectrum β-Lactamase-Producing Strains of Salmonella enterica Serovar London

“…Among the six groups of CTX-M enzymes (1), the CTX-M-1, -2, and -9 groups have been reported in serovars Typhimurium, Virchow, Enteritidis, Kentucky, Infantis, and Oranienburg (1,3,5,12,19). However, to the best of our knowledge this is the first report of a CTX-M-14 enzymeproducing Salmonella serovar London, which suggests a gradual spread of this resistance to various serovars of Salmonella.…”

Characterization of AmpC-Mediated Resistance in Clinical Salmonella Isolates Recovered from Humans during the Period 1992 to 2003 in England and Wales

“…CMY-2 was first identified in a human clinical case of K. pneumoniae from Greece (4). Since then, CMY-2 has been identified in a large number of different human and animal Salmonella serovars (Newport [22], Typhimurium [1], Hadar [25], Senftenberg [12], Infantis [7,14], Agona [7], Ohio [1], Bredeney [1], Wien [2], Heidelberg [16], Mikawasima [17], Montevideo [17], Oranienburg [19], and Choleraesuis [8]) from humans and animals.…”

“…Breakpoints for other antibiotics were as described previously (24). Selected isolates were analyzed by an AmpC multiplex PCR (15), Subsequently, for those showing positive results, the full-length bla CMY or bla DHA PCR amplicon was sequenced as described before (14,15).…”