Dominance of CTX-M-type extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli isolated from patients with community-onset and hospital-onset infection in China.

OBJECTIVE: To investigate CTX-M genotypes among extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-EC) isolated from patients with community-onset and hospital-onset infections in China, their clonality and the distribution of CTX-M variants in different specimens of community-onset and hospital-onset infections. METHODS: ESBL-EC isolates were collected from general hospitals from 2011 to 2012 in China. Broth microdilution method antimicrobial susceptibility testing of 16 antibiotics was performed. Clinical data from community-onset and hospital-onset infections due to ESBL-EC were analyzed. ESBL-encoding genes were amplified by PCR and sequenced, and multilocus sequence typing (MLST) was performed for a random selection of predominant CTX-M type strains identified. RESULTS: A total of 1,168 ESBL-EC isolates were obtained from various clinical specimens, 41.7% of which were responsible for causing community-onset infections. The presence of urinary calculi was higher in community-onset infections, whereas malignancy, cardiovascular and cerebrovascular diseases, dementia, chronic renal disease, diabetes mellitus and surgical treatment were found to have higher proportions in hospital-onset infections. There was no significant difference in trauma between community-onset and hospital-onset infections. 96.2% of the isolates were detected to harbor blaCTX-M genes. blaCTX-M-1 group and blaCTX-M-9 group were detected at 40.7% and 48.7% respectively, and both positive group accounted for 10.6%. blaCTX-M-55 (24.8%) and blaCTX-M-15 (18.2%) were the major genotypes in blaCTX-M-1 group while blaCTX-M-14 (46.8%) was predominant in blaCTX-M-9 group. A comparison of blaCTX-M distribution in different specimens between ESBL-EC causing community-onset and hospital-onset infection showed no significant difference. A total of 229 isolates were tested for MLST. ST131 (14%) was the predominant type. ST648, ST405 and ST1193 were also detected. CONCLUSIONS: Community-onset ESBL-EC has emerged as a common pathogen in China. CTX-M-14 is the most commonly encountered, CTX-M-55 and CTX-M-15 have spread rapidly. ST131 is the predominant clonal group, and the great diversity of CTX-M-producing isolates of E. coli has emerged in China.

Mycoplasma pneumoniae in adult community-acquired pneumonia increases matrix metalloproteinase-9 serum level and induces its gene expression in peripheral blood mononuclear cells.

BACKGROUND: The objective of this study was to assess the concentration of metalloproteinase-2 (MMP-2) and metalloproteinase-9 (MMP-9) in peripheral circulation and their mRNA expression in peripheral blood mononuclear cells (PBMCs) in patients with CAP caused by M. pneumoniae. MATERIAL/METHODS: We prospectively analyzed MMPs in 40 hospitalized patients with M. pneumoniae CAP on admission, and in the convalescent phase. Twenty healthy men were used as controls. Quantitative real-time PCR and ELISA tests were used. RESULTS: MMP-9 mRNA expression in PBMCs was increased in the acute phase of illness compared to the control group as well as in convalescent phase in which case it was statistically significant (Mann-Whitney; p=0.028). The same was found for MMP-9 plasma levels (Mann-Whitney test; p<0.001; p=0.001). Circulating MMP-2 concentration in acute patients was significantly lower than in the control group and convalescent phase (Mann-Whitney test; p=0.012; p=0.001), while no MMP-2 mRNA expression was found in PBMCs. The plasma level of MMP-9 correlated with leukocyte count in peripheral circulation (r=0.67, p<0.001). CONCLUSIONS: We conclude that M. pneumoniae in adult CAP induces activity of MMP-9 in peripheral blood circulation.

Risk factors and clinical outcomes of extended spectrum beta-lactamase (ESBL)-producing Escherichia coli septicemia at Srinagarind University Hospital, Thailand.

Escherichia coli producing extended spectrum beta-lactamase (ESBL) has emerged as a worldwide, public health problem. The aims of this study were to determine the incidence of ESBL-producing E. coli septicemia and evaluate the factors associated with the infection and the clinical outcomes. We reviewed 145 cases of E. coli septicemia among adult patients admitted to Srinagarind University Hospital in northeastern Thailand between 2005 and 2006. The incidence of ESBL-producing E. coli septicemia was 9.9 cases per 10,000 hospital admissions. The factors significantly associated with ESBL-producing E. coli septicemia were: 1) hospital acquisition [odds ratio (OR) 6.46; 95% confidence interval (CI) 2.01-20.79], 2) previous use of a fluoroquinolone, (OR 19.14; 95% CI 5.82-62.96), and 3) use of a central venous catheter (OR, 8.59; 95% CI, 1.11-66.27). Seventy-two hours after receiving empiric treatment, a significantly greater proportion of patients with ESBL-producing E. coli septicemia had a worse clinical outcome than those with non-ESBL producing E. coli septicemia (p = 0.01). The overall mortality rate was significantly higher among the ESBL-producing E. coli septicemia group than the non-ESBL producing E. coli septicemia group (29% vs 11.5%, respectively, p = 0.02). A high APACHE II score, ESBL-producing E. coli septicemia, primary septicemia, and having a non-urinary tract infecting as a source of septicemia were significantly independent factors related to mortality among patients with E. coli septicemia. ESBL-producing E. coli septicemia is an important cause of nosocomial infection and is related to higher mortality risk, especially among those with primary septicemia and secondary septicemia due to a non-urinary tract infection.

Elevated plasma matrix metalloproteinase-9 protein and its gene polymorphism in patients with community-acquired pneumonia.

BACKGROUND: The purpose here was to detect the association among plasma matrix metalloproteinase-9 (MMP-9) concentration, single nucleotide polymorphisms (SNPs) of MMP-9 gene and community-acquired pneumonia (CAP). METHODS: The enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) were, respectively used to measure the plasma MMP-9 level and its gene polymorphisms. RESULTS: The level of plasma of MMP-9 was elevated in patients with CAP as compared to that of normal controls and decreased significantly after treatment. Plasma MMP-9 concentration was significantly correlated with white blood cell (WBC) and neutrophil counts in patients with CAP. No significant difference was found in the genotypes distribution of MMP-9 SNPs, rs3918242, rs17576 or rs2274756, between patients with CAP and normal controls. Plasma MMP-9 concentration was not associated with MMP-9 polymorphism. When the cut-off level of the plasma MMP-9 concentration was set to be 105.02 ng/mL, the odds ratio of plasma MMP-9 for CAP risk was 9.86 (95% confident interval: 4.27-22.75). Plasma MMP-9 level may act as a prediction marker for CAP. CONCLUSIONS: Elevated plasma MMP-9 could be a biological marker for the diagnosis and be a new strategy for target therapy of community-acquired pneumonia.

Serum activity of indoleamine 2,3-dioxygenase predicts prognosis of community-acquired pneumonia.

OBJECTIVES: Indoleamine 2,3-dioxygenase (IDO) catalyzes the rate-limiting step of tryptophan (Trp) degradation in the kynurenine (Kyn) pathway. By depleting Trp, IDO plays a critical role in inducing immune suppression and tolerance. The aim of present study was to investigate serum IDO activity, determined by Kyn-to-Trp ratio (Kyn/Trp ratio), in community-acquired pneumonia (CAP) and to examine its clinical significance. METHODS: This study subjects consisted of 129 consecutive patients with CAP and 64 healthy controls. The concentrations of Kyn and Trp were measured simultaneously by liquid chromatography/electrospray ionization tandem mass spectrometry. RESULTS: The CAP patients had significantly higher Kyn concentrations and significant lower Trp concentrations than the controls (p < 0.0001 and p < 0.0001, respectively). Accordingly, IDO activity was significantly higher (2.4-fold) in the patients than in the controls (p < 0.0001). IDO activity correlated well with PSI (Pneumonia Severity Index) and CURB65 (p = 0.0005 and p < 0.0001, respectively). Moreover, the IDO activity and Kyn concentration were significantly higher in the nonsurvivors and were found to predict mortality in multivariate analysis. CONCLUSIONS: IDO activity was increased in CAP, and this activity was associated with the severity and outcome of this disease. These results suggest that IDO activity can predict prognosis of CAP.

Plasma neutrophil elastase correlates with pulmonary vascular permeability: a prospective observational study in patients with pneumonia.

BACKGROUND AND OBJECTIVE: Little is known about plasma neutrophil elastase (PNE) levels in patients with community-acquired pneumonia (CAP) requiring treatment in the intensive care unit (ICU) or high care unit (HCU). In addition, the influence of PNE on pulmonary vascular permeability in a clinical setting has not been investigated. The aims of this study were (i) to investigate PNE levels in patients with CAP and (ii) to explore the relationship between PNE and pulmonary vascular permeability. METHODS: Fourteen consecutive CAP patients who were admitted to the HCU (n = 8) or ICU (n = 6) were prospectively investigated over a 6-month period. A group of eight patients with hydrostatic pulmonary oedema without CAP served as a control group (CG). PNE levels were measured at regular intervals. The pulmonary vascular permeability index (PVPI) was monitored in all ICU and CG patients, using the PiCCO system. RESULTS: PNE levels were higher in the CAP patients (132 (84-261) ng/mL) than in the CG patients (77 (64-107) ng/mL) (P = 0.04), and were highest in the ICU patients (186 (75-466) ng/mL). The PVPI was higher in the ICU patients (2.85 (1.90-4.00)) than in the CG patients (1.15 (0.75-2.35)) (P = 0.02). PNE levels correlated with PVPI in the ICU patients (r = 0.81, P < 0.001) but there was no correlation among the CG patients (r = 0.14, P = 0.73). CONCLUSIONS: Patients with severe CAP had high levels of PNE, which was closely correlated with PVPI. PNE may be involved in the pathogenesis of severe pneumonia.

Clinical outcomes in a prospective study of community-acquired hepatitis C virus infection in Northern Norway.

OBJECTIVE: Knowledge on the natural course of the morbidity of unselected community-acquired hepatitis C virus (HCV) infection is limited. The aim of our study was to characterize the clinical outcomes of both hepatic and extrahepatic morbidity in patients infected with HCV in a community-based setting in Northern Norway. MATERIAL AND METHODS: This prospective cohort study included 1010 HCV-positive patients diagnosed by recombinant immunoblot assay (RIBA), between 1 January 1990 and 1 January 2000. Questionnaires were sent to those physicians in Northern Norway who had requested the RIBA tests during the relevant period. Data were collected from medical records in the period between 1 January 2004 and 30 June 2006. Access to confidential information was obtained from the Norwegian Directorate of Health. RESULTS: Median age at follow-up was 39 and 41 years in females and males, respectively. In patients with positive HCV RNA status following results were found: Alanine aminotransferase was elevated in 27.4%, decompensated liver disease in 2.9% and hepatocellular carcinoma in 0.4%. Median observation period from estimated acquisition of the disease to follow-up in these patients was 26 years. Depression was reported in 10.7% of chronic infected subjects. Renal failure caused by membranoproliferative glomerulonephritis occurred in 0.2%. CONCLUSIONS: In an unselected HCV-RNA positive population severe liver disease developed in a sub-group of patients. These observations suggest that chronic HCV disease in relatively young subjects may cause a substantial burden on the health system in the future.

Superoxide dismutase, copper and zinc concentrations in platelet-rich plasma of pneumonia patients.

BACKGROUND: The aim of this study was to analyse platelet superoxide dismutase (SOD) activities (total SOD, manganese SOD and copper zinc SOD) and copper (Cu) and zinc (Zn) concentrations during the course of community-acquired pneumonia (CAP), and to compare them between patients with normal platelet count and those who have developed reactive thrombocytosis (RT). METHODS: Platelet count, SOD activities and Cu and Zn concentrations in platelet-rich plasma were measured in patients with CAP on admission and at discharge. RESULTS: Post-therapeutic platelet count increased significantly from the value recorded on admission. By the end of treatment, 42% of patients developed RT. All platelet SOD activities as well as Cu concentration were significantly lower in CAP patients than in control subjects. The initial Zn concentration was greater in CAP patients compared with controls and showed a decrease at discharge. On admission, there was no difference in all SOD activities between either subgroup with normal platelet count or subgroup with RT. At discharge all SOD activities were significantly lower in patients with RT. Also, catalytic activities of those enzymes were significantly lower in both subgroups in comparison with the initial values. Post-therapeutic Cu value was lower in patients with RT in comparison with patients having normal platelet count. Zn concentration decreased significantly at discharge when compared with the initial values only in patients with RT. CONCLUSION: The pattern of changes might be indicative of a certain role of platelets in antioxidant response during treatment in CAP patients.

[Characterization and molecular epidemiology of ESBL in Escherichia coli and Klebsiella pneumoniae in 11 Spanish hospitals (2004)]. / Caracterización y epidemiología molecular de betalactamasas de espectro extendido en Escherichia coli y Klebsiella pneumoniae en once hospitales españoles (2004).

INTRODUCTION: The epidemiological distribution of extended-spectrum beta-lactamase (ESBL) types in Escherichia coli and Klebsiella pneumoniae was evaluated in various hospitals in Spain and compared with previous studies. METHODS: A total of 11 Spanish hospitals participated in this study. Each center collected the first 15 isolates of E. coli and the first 5 of K. pneumoniae suspected of being ESBL-producers and isolated during the first quarter of 2004. Clonal study was done by PFGE after total DNA digestion with XbaI and by ERIC-PCR (Enterobacterial Repetitive Intergenic Consensus Sequences-Polymerase Chain Reaction), typing. ESBL-producers were characterized by isoelectric focusing (IEF), PCR and sequencing. RESULTS: A total of 124 strains were collected. PFGE restriction patterns showed considerable diversity among E. coli strains; 4 clusters of 2 strains each were detected. ESBL characterization of 92 E. coli strains showed a predominance of CTX-M-14 (45.7%), CTX-M-9 (20.6%) and SHV-12 (21.7%). Clonal diversity among the 32 K. pneumoniae strains was less pronounced than in E. coli; 3 clusters included 53.1% of strains. The ESBL detected in these strains included a CTX-M type in 20 cases (62.5%) (CTX-M-1, CTX-M-9, CTX-M-14 and CTX-M-15); a SHV type in 11 (34.4%) (SHV-12 and SHV-5) and TEM-4 (3.1%) in 1 case. CONCLUSION: The E. coli and K. pneumoniae strains analyzed in this period displayed a greater diversity of ESBL than has been observed in previous epidemiological studies. Analysis of clonal relationships revealed a greater diversity in E. coli than in K. pneumoniae.

Angiotensin-converting enzyme (ACE) I/D corrected serum ACE activity and severity assessment of community-acquired pneumonia.

BACKGROUND: Various studies have described decreased serum angiotensin-converting enzyme (ACE) activity in patients with pneumonia. The aim of the present study was to evaluate the role of ACE in pneumonia by comparing ACE insertion/deletion (I/D) genotype corrected serum ACE activity and to establish whether the severity of the disease correlates with lower ACE activity. METHODS: This was a prospective hospital-based observational study including 134 patients with pneumonia. Serum ACE activity was determined at admission, on days 2, 3, 5 and 10 of hospital stay, and at recovery. Based on ACE genotype and reference values, corresponding Z-scores were calculated. Disease severity, quantified by the acute physiology score (APS), and clinical outcome were compared between tertile groups of the Z-scores. RESULTS: A significant decrease in serum ACE activity during an episode of pneumonia with return to control range during recovery was observed for all three genotypes (II, ID and DD). The calculated Z-scores showed a negative correlation with APS scores (p=0.050). No significant association between decreased serum ACE activity and clinical outcome was observed. CONCLUSIONS: Serum ACE activity is significantly decreased during the acute phase of pneumonia. Despite correction for ACE I/D genotype, decreased ACE activity did not show a prognostic value. Further studies are needed to examine the mechanisms behind and diagnostic value of decreased ACE activity in community-acquired pneumonia.

Excessive matrix metalloproteinase-9 in the plasma of community-acquired pneumonia.

BACKGROUND: It has been shown that matrix metalloproteinase-9 (MMP-9) is involved in the pathogenesis of various pulmonary inflammatory diseases. We determined the MMP-9 concentration in the plasma of community-acquired pneumonia (CAP) patients before and after antibiotic treatment. METHODS: Gelatin zymography and ELISA analysis were used to measure MMP-9 activity and MMP-9 level, respectively, in 35 control subjects and 46 CAP patients. RESULTS: WBC counts, neutrophils, MMP-9 activity and MMP-9 level were significantly higher in CAP patients compared with that of control subjects (P<0.001), while MMP-9 activity and MMP-9 level were returned to normal after the antibiotic treatment (P<0.001). In addition, MMP-9 level correlated positively with WBC counts and neutrophils number both before and after the antibiotic treatment. CONCLUSIONS: MMP-9 may play an important role in the pathogenesis of CAP with a positive correlation with the number of neutrophils.

Nosocomial and community-acquired Enterobacter cloacae bloodstream infection: risk factors for and prevalence of SHV-12 in multiresistant isolates in a medical centre.

In a medical centre in northern Taiwan, 60 patients had bloodstream infection caused by Enterobacter cloacae from 1 January 2002 to 30 April 2003. Forty (66.7%) were nosocomial and 26 were caused by multiresistant isolates. Twenty patients died due to the infection. Central venous catheterization and mechanical ventilation were relative risks for nosocomial E. cloacae infection. Age and mechanical ventilation were risk factors for multiresistant E. cloacae infection. Mortality was associated with multiresistant isolates and polymicrobial infection. Pulsed-field gel electrophoresis (PFGE) analysis showed, the 26 multiresistant isolates comprised 12 different types, with type A predominating (12 isolates). Excluding the patients infected with PFGE type A, central venous catheterization was a relative risk for infection, and polymicrobial infection was a risk factor for mortality. All but one of the 26 multiresistant isolates had the extended-spectrum beta-lactamase SHV-12. TEM-1 and ampC beta-lactamase genes were also detected in 25 of the 26 multiresistant isolates. Southern blotting indicated that the SHV-12 gene was located on plasmids. Eleven of the 26 multiresistant isolates had minimum inhibitory concentrations (MIC) > or =16 mg/L for cefepime, which was reduced by the addition of sulbactam for most isolates, resulting in susceptibility. The combination of cefepime and sulbactam may be effective in the treatment of multiresistant E. cloacae bloodstream infection.

[Community-acquired pneumonia: serum adenosine-deaminase activity in the aetiological diagnosis]. / Neumonía adquirida en la comunidad: adenosindesaminasa plasmática como marcador etiológico.

BACKGROUND: Adenosine deaminase (ADA) is a cytoplasmic enzyme which activity is increased in disorders that stimulate cells involved in the immune system. In community-acquired pneumonia (CAP), increased levels of serum ADA have been associated with the presence of atypical microorganisms as the source of the former. Previous studies have shown ADA increases in non-infectious diseases. We evaluated the factors that may influence plasmatic ADA (ADAp) levels in CAP patients. PATIENTS AND METHODS: A study with cases (245 episodes of CAP) and controls (49) was designed, and the differences in ADAp activity with regard to organisms, comorbidity factors and complications were analyzed. A logistic regression analysis was performed. RESULTS: CAP caused by atypical microorganisms were found to have increased ADAp values. Variables that independently increased ADAp levels were: atypical etiology (OR = 5.9), liver disease (OR = 5.8), diabetes mellitus (OR = 1.9), and prior antibiotic consumption (OR = 1.7). CONCLUSIONS: ADAp is an etiologic marker that could be useful in the empiric approach of the treatment of CAP.

The PROTEKT surveillance study: antimicrobial susceptibility of Haemophilus influenzae and Moraxella catarrhalis from community-acquired respiratory tract infections.

This paper presents data relating to Haemophilus influenzae and Moraxella catarrhalis from PROTEKT (1999-2000), a surveillance study that examined the susceptibility of respiratory pathogens to current and new antibacterials. Beta-lactamase production is the principal mechanism of resistance to ampicillin and other beta-lactam antibacterials in H. influenzae and M. catarrhalis. The PROTEKT study showed that globally, the prevalence of beta-lactamase production in H. influenzae varied considerably: of 2948 isolates, 489 (16.6%) were beta-lactamase-positive [range: 1.8% (Italy) to 65% (South Korea)]. Beta-lactamase-negative, ampicillin-resistant (BLNAR) strains of H. influenzae were uncommon (<0.1%) but their very detection highlights the need for continued vigilance. Overall, few isolates of H. influenzae showed resistance to either macrolides or telithromycin. The emergence of clarithromycin-resistant strains is worrying, however, as such isolates may also show resistance to other macrolides. There was a geographical correlation between beta-lactamase production and the prevalence of resistance to chloramphenicol and tetracycline among the H. influenzae isolates. Of 1131 M. catarrhalis isolates, 92% were beta-lactamase-positive. Most isolates, however, were fully susceptible to nearly all the antibacterials tested, except ampicillin. The most active were ciprofloxacin and levofloxacin (both having MIC(90) values of 0.03 mg/L), moxifloxacin (MIC(90) 0.06 mg/L), azithromycin (MIC(90) < or = 0.06 mg/L) and telithromycin (MIC(90) 0.12 mg/L). Overall, there were no concerns in terms of resistance to fluoroquinolones for both H. influenzae and M. catarrhalis. In summary, the PROTEKT surveillance study confirmed the problem of widespread prevalence of beta-lactamase-producing strains of H. influenzae and M. catarrhalis, although these pathogens generally remain susceptible to macrolides, fluoroquinolones and the new ketolide telithromycin.

Extended-spectrum beta-lactamase-producing Enterobacteriaceae strains in community-acquired bacteremia in Southern Israel.

BACKGROUND: In recent years, extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae have emerged in many hospitals worldwide. The increasing dissemination and long-term carriage of these organisms within the community carry tremendous implications on the empirical therapy of community-acquired infection. MATERIAL/METHODS: To evaluate the prevalence and clinical features of community-acquired bacteremia involving ESBL-producing Enterobacteriaceae in southern Israel (ESBL-P) we retrospectively studied all Enterobacteriaceae bacteremias during an 8-month period in the Negev region using medical and laboratory records. Antibiotic susceptibility was determined using the disk-diffusion method. ESBL production was determined using an E-test ESBL strip. Cases involving ESBL-P were compared to those involving non-producing strains (ESBL-NP) using the chi-square test. RESULTS: In all, 187 Enterobacteriaceae bacteremias were detected, of which 119 were community-acquired (63.6%). ESBL-P were found in six cases (5%) which are described herein in greater detail. Patients with ESBL-P bacteremia were older, and were more likely to stay in the intensive-care unit. Urinary catheterization and bed-ridden conditions were significant risk factors for ESBL-P. ESBL-P strains were significantly resistant to nearly all antibiotic agents except for imipienem and piperacillin-tazobactam as opposing to ESBL-NP. Patients with ESBL-P bacteremia were more likely to suffer from complications and had a higher mortality. CONCLUSIONS: This paper is the first to describe community-acquired Enterobacteriaceae bacteremia involving ESBL-P strains in Israel. Although the exact prevalence of these organisms in Israel is currently unknown, our findings suggest that ESBL-producers have already begun to disseminate in our community.

The effect of community-acquired pneumonia on plasma esterases in older people.

INTRODUCTION: Pneumonia is a major cause of morbidity and mortality in older people. The poor outcome of older pneumonia patients despite treatment is still not understood. OBJECTIVE: The aim of this study was to examine the effect of community-acquired pneumonia on enzymes of drug metabolism in older people. METHODS: Fifteen patients (median age 67 years) with a clinical and radiological diagnosis of community-acquired pneumonia and 14 healthy volunteers matched for age and gender (median age 75 years) were recruited. Plasma activities of benzoylcholinesterase, butyrylcholinesterase, acetylcholinesterase and aspirin esterase were determined spectrophotometrically at three time points in pneumonia patients--within 24 h of admission to hospital, 2 days later and 10 days later. Monocyte aryl hydrocarbon hydroxylase (AHH) activity was determined spectrofluorimetrically at the same time points. Enzyme activities were measured at one time point in healthy controls. RESULTS: Mean plasma benzoylcholinesterase activity was significantly lower in pneumonia patients on admission to hospital (mean +/- SEM 848 +/- 100) and after 10 days of treatment (mean +/- SEM 925 +/- 114) than in healthy controls (mean +/- SEM 1333 +/- 84, P < 0.05). Similarly, plasma acetylcholinesterase activity was significantly lower in pneumonia patients on admission (P = 0.007) and after 10 days of treatment (P = 0.01) than in controls. Butyrylcholinesterase activity was lower in pneumonia patients on admission (P = 0.029) than in healthy controls, but improved slightly after treatment so there was no longer a significant difference at 10 days compared with controls (P = 0.077). In contrast there were no significant differences in plasma aspirin esterase activity or induced monocyte AHH activity between pneumonia patients and healthy controls. The activities of benzoylcholinesterase (r = -0.536, P = 0.04), butyrylcholinesterase (r = -0.638, P = 0.01), acetylcholinesterase (r = -0.583, P = 0.022) and aspirin esterase (r = -0.624, P = 0.013) correlated inversely with the British Thoracic Society pneumonia poor prognostic index. CONCLUSION: The activities of several esterases are reduced in older pneumonia patients. Other enzymes including aspirin esterase and induced monocyte AHH activity are unaltered in pneumonia. There was a significant inverse relationship between the activities of all esterases studied and the British Thoracic Society pneumonia poor prognostic index.