Microbiological and Clinical Studies of Legionellosis in 33 Patients with Cancer.

Legionella, a large group of environmental Gram-negative bacteria, represents an occasional cause of pneumonia. We analyzed the microbiological and clinical features of 33 consecutive cases of Legionella infections that occurred at the University of Texas MD Anderson Cancer Center, Houston, TX, from 2002 to 2014. The Legionella strains were isolated from bronchoscopy specimens (32 strains) and a blood culture (1 strain) and were identified by sequencing analysis of the full-length 16S rRNA gene. The 33 strains involved 12 Legionella species or subspecies: 15 strains of L. pneumophila subsp. pneumophila, 3 strains of L. pneumophila subsp. fraseri or L. pneumophila subsp. pascullei, 4 strains of "L. donaldsonii," 3 strains of L. micdadei, and one each of L. bozemanae, L. feeleii, L. gormanii, L. longbeachae, L. maceachernii, L. parisiensis, L. sainthelensi, and Legionella sp. strain D5382. All patients except one asymptomatic carrier showed pneumonia, including one with concurrent bacteremia. Nine patients died, with this infection being the immediate cause of death in six. Twenty-seven patients had underlying hematologic malignancies. Twenty-three patients were leukopenic. Six patients were recipients of allogeneic hematopoietic stem cell transplant, with their infections caused by five Legionella species. Together, these results suggest that diverse Legionella species infect patients with cancer in the Houston area and its vicinity. The five cases of pneumonia due to L. donaldsonii and Legionella sp. D5382 are likely the first reports of human infection with these organisms.

Microbiological and clinical features of four cases of catheter-related infection by Methylobacterium radiotolerans.

Four cases of central venous catheter-related Methylobacterium radiotolerans infection are presented here. The patients were all long-term catheter carriers with an underlying diagnosis of leukemia, and they mostly manifested fevers. The isolated bacterial strains all showed far better growth on buffered charcoal yeast extract agar during the initial isolation and/or subcultures than they did on sheep blood or chocolate agar. This microbiological feature may improve the culture recovery of this fastidious pink Gram-negative bacillus that has rarely been isolated in clinical microbiology laboratories.

Nocardiosis in 132 patients with cancer: microbiological and clinical analyses.

OBJECTIVES: To correlate the microbiological and clinical features of infections caused by Nocardia species. METHODS: We determined the species and drug susceptibility of 138 Nocardia strains isolated from 132 patients at the University of Texas M. D. Anderson Cancer Center (Houston, TX) from 2002 through 2012 and analyzed the clinical features. RESULTS: The 132 patients included 82 men and 50 women with a mean age of 59.1 years. All except two had underlying cancer, and 47 (35.6%) also received a stem cell transplant. These patients experienced 136 episodes of Nocardia infection, including pulmonary infection, abscess of deep skin and soft tissue, bacteremia and dissemination, and brain abscess. The 138 Nocardia strains involved 27 species, of which 20 species have been described since 2000. Common species included Nocardia nova, Nocardia cyriacigeorgica, Nocardia farcinica, and Nocardia abscessus, together accounting for 59.4%. N nova caused most bacteremia cases, whereas N farcinica caused most of the skin and brain infections. Infections with a few recent species likely represented first confirmation or report of human infections. Antimicrobial susceptibility tests of 117 strains showed that they were all susceptible to trimethoprim-sulfamethoxazole and linezolid but variably susceptible to other drugs depending on species. Most patients who were treated for the infection showed improvement or resolution. CONCLUSIONS: Diverse Nocardia species can cause secondary infections in patients with cancer. Timely species identification and antimicrobial susceptibility tests may guide treatment.

Analysis of the leprosy agents Mycobacterium leprae and Mycobacterium lepromatosis in four countries.

OBJECTIVES: To differentiate the leprosy agents Mycobacterium leprae and Mycobacterium lepromatosis and correlate them with geographic distribution and clinicopathologic features. METHODS: Species-specific polymerase chain reactions were used to detect each bacillus in archived skin biopsy specimens from patients with leprosy from Brazil (n = 52), Malaysia (n = 31), Myanmar (n = 9), and Uganda (n = 4). Findings were correlated with clinical and pathologic data. RESULTS: Etiologic species was detected in 46 of the 52 Brazilian patients, including 36 patients with M leprae, seven with M lepromatosis, and three with both bacilli. The seven patients with sole M lepromatosis all had tuberculoid leprosy, whereas only nine of the 36 patients infected with M leprae exhibited this type, and the rest were lepromatous (P < .001). All patients with dual infections had lepromatous leprosy. Of the nine patients from Myanmar, six were test positive: four with M leprae and two with M lepromatosis. Of the Malaysian and Ugandan patients, only M leprae was detected in 27 of the 31 Malaysians and two of the four Ugandans. CONCLUSIONS: The leprosy agents vary in geographic distribution. Finding M lepromatosis in Brazil and Myanmar suggests wide existence of this newly discovered species. The leprosy manifestations likely vary with the etiologic agents.

Septic transfusion reactions during blood transfusion via indwelling central venous catheters.

BACKGROUND: Transfusion of blood products requires a vascular port. Use of an indwelling central venous catheter (CVC) provides this port readily and safely in general; however, potential risks require assessment. STUDY DESIGN AND METHODS: The objective was to examine septic reactions to blood transfusions performed via CVCs owing to subclinical microbial catheter colonization. All transfusion reactions that occurred from 2007 to 2011 at The University of Texas MD Anderson Cancer Center were analyzed and correlated with microbiology culture results. Data on the reactions, including vascular access via a catheter or peripheral venipuncture, were collected prospectively. RESULTS: A total of 999 reactions were reported, with an incidence of two per 1000 transfusion events. A total of 738 reactions occurred in 642 patients during transfusion through a CVC. Among them, 606 reactions occurred in patients that had cultures of blood samples drawn within 7 days before or after reaction. Sixty of these (9.9%) had at least one significant microorganism isolated from their catheters and/or peripheral blood. The blood culture results and timing suggested that these patients likely had catheter-related bloodstream infections caused by transfusion through a CVC with subclinical microbial colonization. Fever and chills occurred in 35 of these patients (58%), which resembled febrile nonhemolytic transfusion reactions. Culture results of the transfused blood products, although not performed in all cases, were mostly negative in these CVC-related reactions. CONCLUSION: Blood transfusion through an indwelling CVC may lead to septic reaction owing to subclinical microbial colonization. This risk should be considered before transfusion and during investigation of transfusion reactions.

Subspecies identification and significance of 257 clinical strains of Mycobacterium avium.

Mycobacterium avium is abundant in the environment. It has four subspecies of three types: the human or porcine type, M. avium subsp. hominissuis; the bird type, including M. avium subsp. avium serotype 1 and serotype 2, 3 (also M. avium subsp. silvaticum); and the ruminant type, M. avium subsp. paratuberculosis. We determined the subspecies of 257 M. avium strains isolated from patients at the M.D. Anderson Cancer Center from 2001 to 2010 and assessed their clinical significance. An assay of multiplex PCR was used for the typing. Results showed M. avium subsp. hominissuis to be most common (n = 238, 92.6%), followed by M. avium subsp. avium serotype 1 (n = 12, 4.7%) and serotype 2, 3 (n = 7, 2.7%). No strains of M. avium subsp. paratuberculosis were found. Of the 238 patients with M. avium subsp. hominissuis, 65 (27.3%) showed evidence of definite or probable infections, mostly in the respiratory tract, whereas the rest had weak evidence of infection. The bird-type subspecies, despite being infrequently isolated, caused relatively more definite and probable infections (10 of 19 strains, 52.6%). Overall, women of 50 years of age or older were more prone to M. avium infection than younger women or men of all ages were. We therefore conclude that M. avium subsp. hominissuis is the dominant M. avium subspecies clinically, that the two bird-type subspecies do cause human infections, and that M. avium infects mainly postmenopausal women. The lack of human clinical isolation of the ruminant type subspecies may need further investigation.

Cytokine gene polymorphisms affect reactivation of cytomegalovirus in patients with cancer.

Reactivation of cytomegalovirus (CMV) in the bloodstream may occur upon severe immune defect or suppression during lifetime. We performed a case controlled study to probe the effects of the host cytokine gene single nucleotide polymorphisms (SNPs) on CMV reactivation. The study subjects were patients with cancer but without stem cell transplantation. The cases were patients tested positive for CMV pp65 antigenemia and the controls were those tested negative. Each case was matched to two controls for similar underlying disease, sex, age, and CMV antibody test status. Ninety cases and 182 controls were chosen and typed for 48 SNPs within 13 cytokines. Alleles of three cytokines were found to be significantly associated with CMV reactivation. Associated with risk of CMV reactivation were the TGFß1-2 allele (10C and 25G) with a hazard ratio (HR) of 1.97% and 95% confidence interval (CI) of 1.14-3.41 and the IL-4-3 allele (-1098T, -590T, and -33T) (HR, 2.08) (95% CI, 1.19-3.63); associated with protection was the IL-2-2 allele (-330T and +166G) (HR, 0.58) (95% CI, 0.35-0.97). Gene dosage, synergism, and antagonism among these alleles were also observed. Our results suggest roles of immunogenetic variations on the immunity against CMV, which may allow clinical CMV risk stratification. Further studies of these alleles are warranted.

The leprosy agents Mycobacterium lepromatosis and Mycobacterium leprae in Mexico.

BACKGROUND: Mycobacterium leprae was the only known cause of leprosy until 2008, when a new species, named Mycobacterium lepromatosis, was found to cause diffuse lepromatous leprosy (DLL), a unique form of leprosy endemic in Mexico. METHODS: We sought to differentiate the leprosy agents among 120 Mexican patients with various clinical forms of leprosy and to compare their relative prevalences and disease features. Archived skin biopsy specimens from these patients were tested for both M. leprae and M. lepromatosis using polymerase chain reaction-based species-specific assays. RESULTS: Etiologic species were confirmed in 87 (72.5%) patients, of whom 55 were infected with M. lepromatosis, 18 with M. leprae, and 14 with both organisms. The endemic regions of each agent differed but overlapped. Patients with M. lepromatosis were younger and were distributed across more states; their clinical diagnoses included DLL (n = 13), lepromatous leprosy (LL) (n = 34), and eight other forms of leprosy. By contrast, the diagnoses of patients with M. leprae did not include DLL but did include LL (n = 15) and three other forms of leprosy. Thus, M. lepromatosis caused DLL specifically (P = 0.023). Patients with M. lepromatosis also showed more variable skin lesions; the extremities were the most common sites of biopsy in these patients. Finally, patients with dual infections manifested all clinical forms and accounted for 16.1% of all species-confirmed cases. CONCLUSIONS: Mycobacterium lepromatosis is another cause of leprosy and is probably more prevalent than M. leprae in Mexico. It mainly causes LL and also specifically DLL. Dual infections caused by both species may occur in endemic areas.

Isolation and characterization of "Pseudomonas andersonii" from four cases of pulmonary granulomas and emended species description.

"Pseudomonas andersonii" is a Gram-negative bacillus initially isolated from a granulomatous lung lesion. Novel species status has not been validated for this single strain. We report four additional cases of pulmonary granuloma involving P. andersonii and further characterize the organism. These patients had pulmonary nodules that were surgically resected and which grew P. andersonii on routine culture. Mycobacterium avium complex was concomitantly isolated in two cases, and fungal structures were identified histopathologically in two other cases. The five P. andersonii strains described to date were similar in growth characteristics, biochemical reactions, matrix-assisted laser desorption ionization-time of flight mass spectrometry protein profiles, and susceptibility to antimicrobial agents. Their 16S rRNA genes were 99.9 to 100% identical but less than 95.0% similar to those of all other known bacteria. The gyrA genes of these strains were 99.5 to 100% identical. These shared features illustrate P. andersonii as a unique and distinct bacterium and support the novel species status of the organism.

Helicobacter pylori bacteremia with sepsis syndrome.

A 65-year-old woman with a history of gastric bleeding, breast cancer, antineoplastic chemotherapy, and prednisone use presented with a fever, chest pain, a dry cough, hypotension, and prominent pulmonary bronchovascular markings. She was treated with piperacillin-tazobactam and azithromycin and rapidly improved. Six days later, the blood culture grew a pleomorphic Gram-negative bacillus. Initial subculture failed, but the organism was identified as Helicobacter pylori by sequencing the 16S rRNA gene. The bacterium eventually grew on brucella agar upon extended incubation.

Chromobacterium haemolyticum sp. nov., a strongly haemolytic species.

A Gram-negative bacterium, strain MDA0585(T), isolated from a sputum culture, was characterized by a polyphasic approach. The 16S rRNA gene and a conserved portion of the DNA gyrase A gene were sequenced and analysed phylogenetically. Strain MDA0585(T) showed the closest relationships with Chromobacterium violaceum ATCC 12472(T) and Chromobacterium subtsugae PRAA4-1(T) (96.1 % and 96.3 % 16S rRNA gene sequence similarity, respectively). The cellular fatty acids of strain MDA0585(T) consisted mainly of C(16 : 0), C(16 : 1)omega7c and C(16 : 1)omega6c (summed feature 3) and C(18 : 1)omega7c and C(18 : 1)omega6c (summed feature 8), a profile that was similar to, but distinguishable from, those of C. violaceum ATCC 12472(T) and C. subtsugae PRAA4-1(T). In culture, strain MDA0585(T) differed from C. violaceum and C. subtsugae in several ways: lack of violet pigmentation, the ability to haemolyse sheep blood, differences in several biochemical reactions and higher resistance to antibiotics. The culture supernatant of strain MDA0585(T) also caused remarkable haemolysis of human erythrocytes. These results suggest that strain MDA0585(T) represents a novel species within the genus Chromobacterium, for which the name Chromobacterium haemolyticum sp. nov. is proposed. The type strain is MDA0585(T) (=CCUG 53230(T)=JCM 14163(T)=DSM 19808(T)).

Rapidly growing mycobacteria: clinical and microbiologic studies of 115 cases.

We analyzed clinical and microbiologic features of 115 cases involving rapidly growing mycobacteria (RGM) isolated at the University of Texas M.D. Anderson Cancer Center, Houston (2000-2005) and identified by 16S ribosomal RNA gene sequencing analysis. At least 15 RGM species were included: Mycobacterium abscessus (43 strains [37.4%]), Mycobacterium fortuitum complex (33 strains [28.7%]), and Mycobacterium mucogenicum (28 strains [24.3%]) most common, accounting for 90.4%. Most M abscessus (32/43) were isolated from respiratory sources, whereas most M mucogenicum (24/28) were from blood cultures. Antimicrobial susceptibility tests showed that M abscessus was the most resistant species; M mucogenicum was most susceptible. From blood and catheter sources, 46 strains (40.0%) were isolated; 44 represented bacteremia or catheter-related infections. These infections typically manifested high fever (mean temperature, 38.9 degrees C), with a high number of RGM colonies cultured. All infections resolved with catheter removal and antibiotic therapy. Six strains (M abscessus and M fortuitum only) were from skin, soft tissue, and wound infections. There were 59 strains from respiratory sources, and 28 of these represented definitive to probable infections. Prior lung injuries and coisolation of other pathogenic organisms were common. Overall, 78 RGM strains (67.8%) caused true to probable infections without direct deaths.

Invasive Streptomyces infections: six cases and literature review.

Streptomyces are saprophytic soil organisms rarely known to cause invasive infections other than mycetoma. We report 6 cases of invasive Streptomyces infections and review 13 previously reported cases. Our series included 2 cases of lung abscess or pneumonitis, 3 cases of central venous catheter-related bloodstream infection, and I case of possible hypersensitivity pneumonitis. Most previous cases also included lung infections and bloodstream infections. Preexisting conditions, such as cancer, AIDS or HIV infection, presence of a central venous catheter, and prosthetic heart valve, were present in all cases since 1985. Diverse Streptomyces species were involved, consistent with the highly opportunistic nature of the infections. Clinical management depended on the clinical situation of individual cases without consensus. Available susceptibility data showed that Streptomyces organisms were consistently susceptible to amikacin; frequently susceptible to imipenem, clarithromycin or erythromycin, minocycline, and trimethoprim-sulfamethoxazole; and infrequently susceptible to ciprofloxacin and ampicillin. The diagnosis of Streptomyces infection required microbiologic and pathologic correlation to rule out contamination.

Epidemiologic analysis of reactivated cytomegalovirus antigenemia in patients with cancer.

The epidemiologic features of reactivated cytomegalovirus (CMV) antigenemia were studied among 4,382 cancer patients who were cared for and tested at the University of Texas M. D. Anderson Cancer Center from 2001 to 2004. The effects of stem cell transplant (SCT) status, underlying disease, age, sex, ethnicity, and antibody status (prior to CMV exposure) on the incidence of CMV antigenemia were determined; and the CMV burdens were quantified. Antigenemia occurred in 9.3% of patients with non-SCT (n = 2511), 12.0% with autologous SCT (n = 582), and 39.1% with allogeneic SCT (n = 1289). Non-SCT patients with lymphoid tumors had a significantly higher rate of antigenemia than those with myeloid tumors (13.6% versus 3.9%) (P < 0.001); however, after allogeneic SCT, the underlying diseases had little effect, except for multiple myeloma (56.8%) (P = 0.014). Among the allogeneic SCT recipients, higher CMV antigenemia rates were also associated with female sex, older age, and positivity for pre-SCT CMV antibody. Depending on the underlying disease and its associated initial CMV risk, allogeneic SCT increased the risk by 2.6- to 29.6-fold (overall, 4.0-fold). With or without SCT, Asians had the highest CMV antigenemia rates and burdens, followed by blacks, Hispanics, and whites, and these partially correlated with antibody prevalence. Among the 808 patients with antigenemia, the circulating peak CMV burden was significantly higher among non-SCT patients (geometric mean, 18.7 positive cells per 10(6) leukocytes) than among allogeneic SCT patients (geometric mean, 7.7 positive cells per 10(6) leukocytes) or autologous SCT patients (geometric mean, 7.0 positive cells per 10(6) leukocytes) who underwent monitoring for CMV. Together, these results allow stratification of CMV risks and suggest a substantial CMV reactivation among non-SCT cancer patients and, thus, the need for better diagnosis and control.

Viridans streptococci isolated by culture from blood of cancer patients: clinical and microbiologic analysis of 50 cases.

Clinical and microbiologic studies of 50 cases of viridans streptococcal bacteremia in cancer patients were performed. The bacteria were identified to species level by sequencing analysis of the 16S rRNA gene. At least nine Streptococcus spp. were found, including S. mitis (25 strains, 50.0% of 50); currently unnamed Streptococcus spp. (11 strains); S. parasanguis (five strains); S. anginosus (three strains); S. salivarius (two strains); and one strain each of S. gordonii, S. sanguis, S. sobrinus, and S. vestibularis. There were no S. oralis strains. Among 11 antibiotics of nine classes tested, no resistance to vancomycin, linezolid, or quinupristin-dalfopristin was seen. Resistance to penicillin (MIC, 4 to 12 mug/ml) was noted only among S. mitis strains (28.0%, 7/25) and not non-S. mitis strains (0/25) (P = 0.004). Significantly more S. mitis strains than non-S. mitis strains were resistant to fluoroquinolones and to > or =3 classes of antibiotics. Isolation of quinolone-resistant organisms was associated with the prior usage of quinolones (P = 0.002). Quantitative blood cultures showed that the strains resistant to levofloxacin or gatifloxacin were associated with higher colony counts than were their corresponding nonresistant strains. The young and elderly patients also had higher levels of bacteremia caused predominantly by S. mitis. Septic shock was present in 17 (34.0% of 50) patients, and 13 of those cases were caused by S. mitis (P = 0.007). These results suggest that S. mitis is the most common cause of viridans streptococcal bacteremia in cancer patients and is more resistant to antibiotics than other species.

Clinical significance and epidemiologic analyses of Mycobacterium avium and Mycobacterium intracellulare among patients without AIDS.

The clinical significance and prevalence of Mycobacterium avium and Mycobacterium intracellulare were analyzed in a cohort of 7,472 patients who, from 1999 to 2003, sought care at the University of Texas M.D. Anderson Cancer Center, Houston, and had cultures performed for mycobacteria. Patients were stratified for age, sex, and underlying diseases, and bacteria were identified by 16S rRNA gene sequencing. M. avium was isolated in 62 (0.83%) of 7,472 patients and M. intracellulare in 65 (0.87%). Clinically, only 10 of the 62 (16.2%) patients with M. avium had probable to definite evidence of infection, whereas the majority (83.8%) had weak evidence of infection. Sex and age did not affect the isolation or infection of M. avium. Hematological tumors predisposed to M. avium colonization but not infection. In contrast, 41 of the 65 (63.1%) patients with M. intracellulare had probable to definite infection, a level much higher than those with M. avium (P < 0.001). M. intracellulare was more prevalent in women (1.33% of 3,311) than in men (0.50% of 4,161) (P < 0.001), and underlying diseases had no effect in women. Men with lung cancer had a higher prevalence (1.37%) than men without (0.34%) (4.0-fold; P < 0.001), but it was similar to that in women. A marked age trend for the isolation of M. intracellulare among women was noted: 0.27% (1-fold) for ages of <50 years, 0.85% (3.1-fold) for ages 50 to 59 years, 1.50% (5.6-fold) for ages 60 to 69 years, and 3.74% (13.9-fold) for ages >/=70 years (trend, P < 0.001). The combined rate for women >/=50 was 1.86% (95% confidence interval [1.30 to 2.42%]) (6.9-fold). Together, these results suggest that, among non-AIDS patients, M. intracellulare is more pathogenic and tends to infect women increasingly beyond menopause (age >/=50 years) regardless of underlying disease. The prevalence rate of 1.86% in postmenopausal women suggests the need to further investigate the public health significance of M. intracellulare.

Brevundimonas diminuta infections and its resistance to fluoroquinolones.

OBJECTIVES: To report infections caused by Brevundimonas diminuta and antibiotic studies of this Gram-negative bacterium. PATIENTS AND METHODS: Seven patients with infection and eight bacterial strains were studied. Tests included antibiotic susceptibility and analysis of the DNA gyrase and topoisomerase genes and the effect of efflux pump inhibitor Phe-Arg-beta-naphthylamide (PANA). RESULTS: The patients all had underlying disease of cancer. The infections involved bloodstream (one case), intravascular catheter (four cases), urinary tract (one case) and pleural space (one case of empyema). Fever up to 39.2 degrees C characterized these infections, which resolved upon treatment by combination antibiotics. Microbiologically, all organisms were resistant to multiple fluoroquinolones and cefepime, but were susceptible to amikacin, imipenem and ticarcillin/clavulanate. These quinolone-resistant B. diminuta strains were probably selected out by the prophylactic use of a quinolone in six of these patients. Additionally, the B. diminuta type strain ATCC 11568(T) that was isolated before the quinolone era from water was also resistant to ciprofloxacin and intermediate to levofloxacin, suggesting intrinsic quinolone resistance. The DNA gyrase and topoisomerase of six analysed strains all contained GyrA Ala-83 and Met-87, GyrB Leu-466 or Thr-466, and ParC Gln-57, Val-66 and Ala-80 that were probably the cause of fluoroquinolone resistance. PANA had nearly negligible effect. CONCLUSIONS: B. diminuta is intrinsically resistant to fluoroquinolones and can be selected out to cause infections.

Oral Campylobacter species involved in extraoral abscess: a report of three cases.

Oral Campylobacter species are rarely reported to cause extraoral infections. Here we present three cases of extraoral abscess caused by an oral Campylobacter sp. and a Streptococcus sp. The Campylobacter species were all isolated anaerobically and identified by sequencing analysis of the 16S rRNA gene. The cases included a breast abscess caused by Campylobacter rectus and a non-group A beta-hemolytic streptococcus in a patient with lymphoma, a liver abscess caused by Campylobacter curvus and an alpha-hemolytic streptococcus in a patient with complicated ovarian cancer, and a postobstructive bronchial abscess caused by C. curvus and group C beta-hemolytic Streptococcus constellatus in a patient with lung cancer. The abscesses were drained or resected, and the patients were treated with antibiotics with full resolution of the lesions. The C. curvus cases are likely the first reported infections by this organism, and the C. rectus case represents the second such reported extraoral infection.