Klebsiella pneumoniae related community-acquired acute lower respiratory infections in Cambodia: clinical characteristics and treatment.

BACKGROUND: In many Asian countries, Klebsiella pneumoniae (KP) is the second pathogen responsible for community-acquired pneumonia. Yet, very little is known about KP etiology in ALRI in Cambodia, a country that has one of the weakest medical infrastructures in the region. We present here the first clinico-radiological description of KP community-acquired ALRI in hospitalized Cambodian patients. METHODS: Through ALRI surveillance in two provincial hospitals, KP was isolated from sputum and blood cultures, and identified by API20E gallery from patients ≥ 5 years-old with fever and respiratory symptoms onset ≤14 days. Antibiotics susceptibility testing was provided systematically to clinicians when bacteria were isolated. We collected patients' clinical, radiological and microbiological data and their outcome 3 months after discharge. We also compared KP-related with other bacteria-related ALRI to determine risk factors for KP infection. RESULTS: From April 2007 to December 2009, 2315 ALRI patients ≥ 5 years-old were enrolled including 587 whose bacterial etiology could be assigned. Of these, 47 (8.0%) had KP infection; their median age was 55 years and 68.1% were females. Reported prior medication was high (42.5%). Patients' chest radiographs showed pneumonia (61.3% including 39% that were necrotizing), preexisting parenchyma lesions (29.5%) and pleural effusions alone (4.5%) and normal parenchyma (4.5%). Five patients had severe conditions on admission and one patient died during hospitalization. Of the 39 patients that were hospital discharged, 14 died including 12 within 1 month after discharge. Only 13 patients (28%) received an appropriate antibiotherapy. Extended-spectrum beta-lactamases (ESBL) - producing strains were found in 8 (17.0%) patients. Female gender (Odds ratio (OR) 2.1; p = 0.04) and diabetes mellitus (OR 3.1; p = 0.03) were independent risk factors for KP-related ALRI. CONCLUSIONS: KP ALRI in Cambodia has high fatality rate, are more frequently found in women, and should be considered in diabetic patients. The extremely high frequency of ESBL-producing strains in the study is alarming in the context of uncontrolled antibiotic consumption and in absence of microbiology capacity in most public-sector hospitals.

Evolutionary history of Helicobacter pylori sequences reflect past human migrations in Southeast Asia.

The human population history in Southeast Asia was shaped by numerous migrations and population expansions. Their reconstruction based on archaeological, linguistic or human genetic data is often hampered by the limited number of informative polymorphisms in classical human genetic markers, such as the hypervariable regions of the mitochondrial DNA. Here, we analyse housekeeping gene sequences of the human stomach bacterium Helicobacter pylori from various countries in Southeast Asia and we provide evidence that H. pylori accompanied at least three ancient human migrations into this area: i) a migration from India introducing hpEurope bacteria into Thailand, Cambodia and Malaysia; ii) a migration of the ancestors of Austro-Asiatic speaking people into Vietnam and Cambodia carrying hspEAsia bacteria; and iii) a migration of the ancestors of the Thai people from Southern China into Thailand carrying H. pylori of population hpAsia2. Moreover, the H. pylori sequences reflect iv) the migrations of Chinese to Thailand and Malaysia within the last 200 years spreading hspEasia strains, and v) migrations of Indians to Malaysia within the last 200 years distributing both hpAsia2 and hpEurope bacteria. The distribution of the bacterial populations seems to strongly influence the incidence of gastric cancer as countries with predominantly hspEAsia isolates exhibit a high incidence of gastric cancer while the incidence is low in countries with a high proportion of hpAsia2 or hpEurope strains. In the future, the host range expansion of hpEurope strains among Asian populations, combined with human motility, may have a significant impact on gastric cancer incidence in Asia.

Correlation between antibiotic susceptibilities and genotypes in Neisseria gonorrhoeae from different geographical origins: determinants monitoring by real-time PCR as a complementary tool for surveillance.

OBJECTIVE: To determine in Neisseria gonorrhoeae (NG) isolates from different geographical areas whether monitoring of major determinants involved in chromosomal antimicrobial resistance correlated with phenotypes and could constitute complementary tools for surveillance. METHODS: Real-time multiplex PCR assays targeting penA, mtrR, penB, ponA, gyrA and parC determinants were applied to 169 NG extracts. Minimum inhibitory concentrations for penicillin and ciprofloxacin were determined by E tests, and beta-lactamase production was analysed using nitrocefin discs. RESULTS: A total of 169 NGs were examined, 110 from New Caledonia, 44 from Madagascar and 15 from Cambodia. Despite the heterogeneity in the number of isolates tested, the susceptibility trends observed in the different geographic areas studied showed a good fit with the multigene genotypes. In addition, features related to a specific geographical diversity were found: (1) a high prevalence of strains harbouring the porB1a allele and showing reduced penicillin susceptibility in Madagascar and Cambodia (39% and 40% respectively); (2) almost all strains from Cambodia were resistant to the drugs tested (11/15 and 14/15 resistant to penicillin and ciprofloxacin respectively); and (3) identification of novel penB and mtrR genotypes associated with a moderately decreased penicillin susceptibility in New Caledonia (mtrR novel genotype in 47% of intermediate vs 14% of susceptible isolates). CONCLUSIONS: Showing a good correlation with phenotypic trends of susceptibility, multiplex real-time PCR assays could be used successfully for prospective epidemiological studies notably by characterising mtrR and penB determinants for their fundamental and complementary roles in increasing the antibiotic resistance. These molecular tools could also provide useful alternative surveillance tools for non-viable strains.