Genome Sequences of Bordetella pertussis Isolates from Outbreaks in Northeastern Mexico.

Here, we report the draft genome sequences of 4 Bordetella pertussis isolates which correspond to major clones isolated between 2008 and 2014 from two outbreaks in northeastern Mexico. The B. pertussis clinical isolates belong to the ptxP3 lineage, and they are grouped into two major clusters, defined by the fimH allele.

Generalized and Prolonged Use of Gentamicin-Lock Therapy Reduces Hemodialysis Catheter-Related Infections Due to Gram Negatives.

INTRODUCTION: The incidence of catheter-related bloodstream infections (CRBSI) ranges from 2.2 to 5.5 episodes per 1,000 catheter-days. Our aim was to evaluate the utility of a generalized and prolonged gentamicin-lock therapy in patients undergoing hemodialysis (HD) in a third-level hospital for the reduction in CRBSI. METHODS: A prospective cohort analyzed before and after intervention. During intervention periods after each HD-session, the catheter lumens were locked with gentamicin/heparin for all patients compared to nonintervention periods were the same procedure was performed without gentamicin. Active surveillance was performed for HD CRBSI. Microbiologic assessment and epidemiological data were gathered. Continuous hand hygiene and water quality monitoring were performed. RESULTS: The rates of CRBSI were reduced from 1.28 to 0.2 cases per 1,000 catheter-days when the lock therapy was employed (p = 0.001) The greatest reduction was for CRBSI caused by Pseudomonas aeruginosa were no cases were recorded during the intervention periods (p = 0.001). There was a significant reduction in the total number of isolates; Gram-negative bacterial species (-97.2%) and Gram-positive bacterial species (-61.5%) although only the former reached statistical significance (p = 0.0001). The difference in the absolute risk reduction was 20.56% (95% CI 14.46-26.66%), the calculated Number Needed to Treat was 5 (95% CI 3.8-6.9). No adverse effects were noted. CONCLUSION: In the current study, gentamicin-lock therapy was associated with a significant reduction in CRBSI specially with P. aeruginosa and other Gram-negative bacteria. It proved to be safe and effective intervention when applied to the entire population of HD patients.

Non-typeable Haemophilus influenzae biofilm production and severity in lower respiratory tract infections in a tertiary hospital in Mexico.

Non-typeable Haemophilus influenzae (NTHi) is a common opportunistic bacterial pathogen that primarily infects the respiratory mucosa. This study was conducted to assess clinical and microbiological data related to disease severity in patients with lower respiratory tract infections caused by NTHi in a tertiary care hospital in Mexico. NTHi isolates were subjected to serotyping, antimicrobial susceptibility evaluationand analyses of ß-lactamase production, genetic relatednessand biofilm formation. Clinical and demographic data were retrieved from patients' records. The mean age of the patients was 40.3 years; the majority (n=44, 72.1 %) were male. The main comorbidities were arterial hypertension (n=22, 36.1 %) and diabetes mellitus (n=17, 27.9 %). NTHi isolates (n=98) were recovered from tracheal aspirate (n=57, 58.2 %), sputum (n=26, 26.5 %)and bronchial aspirate (n=15, 15.3 %) specimens. Low resistance to cefotaxime (n=0, 0.0 %), rifampin (n=1, 1.1 %) and chloramphenicol (n=3, 3.2 %) and greater resistance to ampicillin (n=30, 32.3 %) and trimethoprim-sulfamethoxazole (n=49, 52.7 %) were detected. ß-Lactamase production was found in 17 (17.3 %) isolates. Isolates displayed high genetic diversity, and only 10 (10.2 %) were found to be biofilm producers. The antimicrobial susceptibility patterns of biofilm-producing and non-producing isolates did not differ. Biofilm production was associated with prolonged hospital stay (P=0.05). Lower respiratory NTHi isolates from Mexico showed low antimicrobial resistance and weak biofilm production. Younger age was correlated with lower Acute Physiology and Chronic Health Evaluation II score (moderate, P=0.07; severe, P=0.03).

Stenotrophomonas maltophilia in Mexico: antimicrobial resistance, biofilm formation and clonal diversity.

Stenotrophomonas maltophilia is an important multidrug-resistant nosocomial pathogen associated with high mortality. Our aim was to examine antimicrobial susceptibility, biofilm production and clonal relatedness of clinical isolates of S. maltophilia. S. maltophilia isolates were collected between 2006 and 2013 from two tertiary care hospitals in Mexico. Antimicrobial susceptibility was evaluated by the broth microdilution method. PCR was used to determine the presence of ß-lactamase genes L1 and L2. Biofilm formation was assessed with crystal violet staining. Clonal relatedness was determined by PFGE. Among the 119 collected S. maltophilia isolates, 73 (61.3%) were from the respiratory tract. Resistance levels exceeded 75% for imipenem, meropenem, ampicillin, aztreonam, gentamicin and tobramycin. Resistance to trimethoprim-sulfamethoxazole was 32.8%. L1 and L2 genes were detected in 77.1% (91/118) and 66.9% (79/118) of isolates, respectively. All S. maltophilia strains were able to produce biofilms. Strains were classified as weak (47.9%, 57/119), moderate (38.7%, 46/119), or strong (13.4%, 16/119) biofilm producers. A total of 89 distinct PFGE types were identified and 21.6% (22/102) of the isolates were distributed in nine clusters. This is the first study in Mexico to reveal characteristics of clinical isolates of S. maltophilia. Clonal diversity data indicate low cross-transmission of S. maltophilia in a hospital setting. The high antibiotic resistance underscores the need for continuous surveillance of S. maltophilia in hospital settings in Mexico.