Hector R. Perez-Gomez

Identifying Undetected Cases of Chronic Kidney Disease in Mexico. Targeting High-risk Populations

BACKGROUND AND AIMS Chronic kidney disease (CKD) is a major public health problem in Mexico. Current guidelines recommend routine CKD testing in patients at increased risk for CKD. We undertook this study to examine the diagnostic yield of targeted screening (case-finding) for CKD in high-risk populations in rural and urban communities in Jalisco, Mexico. METHODS In a cross-sectional study, we did laboratory tests searching for CKD and its risk factors and compared the characteristics of participants with those reported by the National Health and Nutrition Survey 2006 (NHNS). Individuals who were aware that they had CKD and those <18 years of age were excluded. RESULTS There were 9,169 participants assessed: 28.7% were men and mean age was 55.6 ± 13.7 years. They were predominantly female (71.3 vs. 55.6%, p = 0.0001) and older (55.59 ± 0.1 vs. 42.5 ± 0.3 years, p = 0.0001) than the NHNS population. Self-reported diabetes (41.9 vs. 7.3%, p = 0001) and fasting blood sugar >126 mg/dl (56.1 vs. 14.4%, p = 0.0001) were more prevalent among the participants; self-reported hypertension (41.9 vs. 7.3%, p = 0.0001), systolic blood pressure ≥ 140 mm Hg or diastolic blood pressure ≥ 90 mm Hg (52.5 vs. 43.2%, p = 0.0001), and obesity (42.8. vs. 29.3%, p = 0.0001) were also more frequent among participants. There were 19.7% with proteinuria; CKD was more prevalent among the high risk participants in our study (31.3 vs. 8.0%, p = 0.0001) than in the general population. CONCLUSIONS CKD was detected frequently in high-risk Mexican populations. Trials of case-finding and intervention are feasible and warranted in Mexico.

Resistance trends in gram-negative bacteria: surveillance results from two Mexican hospitals, 2005–2010

BackgroundHospital-acquired infections caused by multiresistant gram-negative bacteria are difficult to treat and cause high rates of morbidity and mortality. The analysis of antimicrobial resistance trends of gram-negative pathogens isolated from hospital-acquired infections is important for the development of antimicrobial stewardship programs. The information obtained from antimicrobial resistant programs from two hospitals from Mexico will be helpful in the selection of empiric therapy for hospital-acquired gram-negative infections.FindingsTwo thousand one hundred thirty two gram-negative bacteria collected between January 2005 and December 2010 from hospital-acquired infections occurring in two teaching hospitals in Mexico were evaluated. Escherichia coli was the most frequently isolated gram-negative bacteria, with >50% of strains resistant to ciprofloxacin and levofloxacin. Klebsiella spp. showed resistance rates similar to Escherichia coli for ceftazidime (33.1% vs 33.2%), but exhibited lower rates for levofloxacin (18.2% vs 56%). Of the samples collected for the third most common gram-negative bacteria, Pseudomonas aeruginosa, >12.8% were resistant to the carbapenems, imipenem and meropenem. The highest overall resistance was found in Acinetobacter spp. Enterobacter spp. showed high susceptibility to carbapenems.ConclusionsE. coli was the most common nosocomial gram-negative bacilli isolated in this study and was found to have the second-highest resistance to fluoroquinolones (>57.9%, after Acinetobacter spp. 81.2%). This finding represents a disturbing development in a common nosocomial and community pathogen.

Clostridium difficile outbreak caused by NAP1/BI/027 strain and non-027 strains in a Mexican hospital

BACKGROUND Clostridium difficile infections caused by the NAP1/B1/027 strain are more severe, difficult to treat, and frequently associated with relapses. METHODS A case-control study was designed to examine a C. difficile infection (CDI) outbreak over a 12-month period in a Mexican hospital. The diagnosis of toxigenic CDI was confirmed by real-time polymerase chain reaction, PCR (Cepheid Xpert C. difficile/Epi). RESULTS During the study period, 288 adult patients were evaluated and 79 (27.4%) patients had confirmed CDI (PCR positive). C. difficile strain NAP1/B1/027 was identified in 31 (39%) of the patients with confirmed CDI (240 controls were included). Significant risk factors for CDI included any underlying disease (p<0.001), prior hospitalization (p<0.001), and antibiotic (p<0.050) or steroid (p<0.001) use. Laboratory abnormalities included leukocytosis (p<0.001) and low serum albumin levels (p<0.002). Attributable mortality was 5%. Relapses occurred in 10% of patients. Risk factors for C. difficile NAP1/B1/027 strain infections included prior use of quinolones (p<0.03). Risk factors for CDI caused by non-027 strains included chronic cardiac disease (p<0.05), chronic renal disease (p<0.009), and elevated serum creatinine levels (p<0.003). Deaths and relapses were most frequent in the 027 group (10% and 19%, respectively). CONCLUSIONS C. difficile NAP1/BI/027 strain and non-027 strains are established pathogens in our hospital. Accordingly, surveillance of C. difficile infections is now part of our nosocomial prevention program.

Genetic Diversity of Mycobacterium tuberculosis from Guadalajara, Mexico and Identification of a Rare Multidrug Resistant Beijing Genotype

Determining the genetic diversity of M. tuberculosis strains allows identification of the distinct Mycobacterium tuberculosis genotypes responsible for tuberculosis in different regions. Several studies have reported the genetic diversity of M. tuberculosis strains in Mexico, but little information is available from the state of Jalisco. Therefore, the aim of this study was to determine the genetic diversity of Mycobacterium tuberculosis clinical isolates from Western Mexico. Sixty-eight M. tuberculosis isolates were tested for susceptibility to first-line drugs using manual Mycobacteria Growth Indicator Tube method and genotyped using spoligotyping and IS6110-restriction fragment length polymorphism (RFLP) pattern analyses. Forty-seven (69.1%) isolates were grouped into 10 clusters and 21 isolates displayed single patterns by spoligotyping. Three of the 21 single patterns corresponded to orphan patterns in the SITVITWEB database, and 1 new type that contained 2 isolates was created. The most prevalent lineages were T (38.2%), Haarlem (17.7%), LAM (17.7%), X (7.4%), S (5.9%), EAI (1.5%) and Beijing (1.5%). Six (12.8%) of the clustered isolates were MDR, and type 406 of the Beijing family was among the MDR isolates. Seventeen (26.2%) isolates were grouped into 8 clusters and 48 isolates displayed single patterns by IS6110-RFLP. Combination of IS6110-RFLP and spoligotyping reduced the clustering rate to 20.0%. The results show that T, Haarlem, and LAM are predominant lineages among clinical isolates of M. tuberculosis in Guadalajara, Mexico. Clustering rates indicated low transmission of MDR strains. We detected a rare Beijing genotype, SIT406, which was a highly resistant strain. This is the first report of this Beijing genotype in Latin America.

Characterization of phenotypic and genotypic drug resistance patterns of Mycobacterium tuberculosis isolates from a city in Mexico

INTRODUCTION The emergence of multidrug-resistant (MDR) Mycobacterium tuberculosis strains has become a worldwide health care problem, making treatment of tuberculosis difficult. The aim of this study was to determine phenotypic resistance and gene mutations associated with MDR of clinical isolates of Mycobacterium tuberculosis from Guadalajara, Mexico. METHODS One hundred and five isolates were subjected to drug susceptibility testing to first line drugs using the proportion and Mycobacteria Growth Indicator Tube (MGIT) methods. Genes associated with isoniazid (inhA, katG, ahpC) and rifampicin (rpoB) resistance were analyzed by either pyrosequencing or PCR-RFLP. RESULTS Resistance to any drug was detected in 48.6% of isolates, of which 40% were isoniazid-resistant, 20% were rifampicin-resistant and 19% were MDR. Drug-resistant isolates had the following frequency of mutations in rpoB (48%), katG (14%), inhA (26%), ahpC (26%). Susceptible isolates also had a mutation in ahpC (29%). CONCLUSIONS This is the first analysis of mutations associated with MDR of M. tuberculosis in Guadalajara. Commonly reported mutations worldwide were found in rpoB, katG and inhA genes. Substitution C to T in position -15 of the ahpC gene may possibly be a polymorphism.

Chronic kidney disease in homeless persons in Mexico.

Little is known about the prevalence of chronic kidney disease (CKD) among the homeless in Mexico. The role of substance abuse, alcoholism, and homelessness in CKD has not been properly evaluated. We screened 260 homeless individuals in the state of Jalisco, Mexico, for the presence of CKD and its risk factors, and compared their characteristics with those from a separate cohort of poor Jalisco residents and with a survey of the general Mexican population. CKD was more prevalent among the homeless than among the poor Jalisco population (22% vs. 15.8%, P=0.0001); 16.5% had stage 3, 4.3% stage 4, and 1.2% stage 5. All were unaware of having CKD. Only 5.8% knew they had diabetes, but 19% had fasting blood sugar >126 mg/dl; 3.5% knew they were hypertensive but 31% had systolic blood pressure ⩾140 mm Hg or diastolic blood pressure ⩾90 mm Hg. Alcoholism was less common than in the poor Jalisco population (23.5% vs. 32.3%, P=0.002), but tobacco smoking (34.6% vs. 21.5%, P=0.0001) and substance abuse (18% vs. 1.1%, P=0.0001) were more prevalent among the homeless. Likewise, chronic viral infections such as HIV (4.5% vs. 0.3%, P=0.0001) and HCV (7.7% vs. 1.4%, P=0.0001) were also significantly higher among the homeless than in the general population. In conclusion, CKD and its risk factors are highly prevalent among the homeless individuals in Jalisco, Mexico. Lack of awareness of having diabetes and hypertension is highly common, as is substance abuse. Programs aiming to prevent CKD and its risk factors in Mexico should specifically target this high-risk population.

New Delhi Metallo-Beta-Lactamase (NDM-1)-Producing Klebsiella Pneumoniae Isolated from a Burned Patient

Patient: Male, 32 Final Diagnosis: NDM-1-producing Klebsiella pneumoniae • bacteremia Symptoms: Fever Medication: — Clinical Procedure: None Specialty: Infectious Diseases Objective: Diagnostic/therapeutic accidents Background: Infections affecting burn patients are frequently caused by Staphylococcus aureus, Pseudomonas aeruginosa, and Enterobacteriaceae species. Infections with these pathogens have become increasingly difficult to treat due to evolving antibiotic resistance mechanisms, including the production of carbapenemases. Case Report: The present case report describes the evolution of a burn patient with polymicrobial healthcare-associated burn infections, including a bloodstream infection due to an emergent multidrug-resistant New Delhi metallo-beta-lactamase (NDM-1)-producing Klebsiella pneumoniae. During hospitalization, initial antibiotic treatment eradicated some of the infecting species. Newer isolates were found to be multidrug-resistant and required unique antibiotic combinations. The patient’s condition continued to deteriorate after the isolation of multidrug-resistant P. aeruginosa and NDM-1-positive K. pneumoniae from the blood. Conclusions: This case report illustrates the need for adequate antibiotic therapies in burn patients with subsequent infections due to a carbapenemase-producing multidrug-resistant bacteria. The potential danger of new bacterial pathogens should be considered in this group of susceptible patients.

Rapidly Growing Mycobacterial Infections of the Skin and Soft Tissues Caused by M. fortuitum and M. chelonae

Purpose of ReviewNon-tuberculous mycobacteria (NTM) have emerged as pathogens of clinical importance in human health as etiological agents of opportunist infections. Although NTM are known to cause systemic infections in immunocompromised subjects primarily in HIV patients, yet the growing number of immunosuppressed patients with new therapies and even more recently in non-immunocompromised subjects often localized infections of the lungs or skin and soft tissues (S&STI) but with a new clinical spectrums. Our goal is to report distinct patterns of infections according to the clinical and immunological settings and management options.Recent FindingsMycobacteria are efficacious pathogens because of their ability to survive and reproduce within the macrophages because of mechanisms of evasion of the host defenses and also because of their capacity to produce biofilms that facilitate their permanence in environmental reservoirs. Thus, both community and healthcare-associated infections have been reported. Also, we emphasize the concept of the new NTM complex of rapid growing Mycobacterium fortuitum-vaccae and Mycobacterium abscessus-chelonae (RGM) based on genetic and molecular characteristics that differentiate members according to the 16S rRNA gene clade and overall genome similarity.SummaryS&STI by RGM should be considered when response to standard antibiotic therapy is deficient and microbiological work-up is negative. Effective treatment of these RGM pathogens includes surgical treatment with combined antimicrobial therapy; resistance to first-line anti-tuberculous drugs is common so therapy should be based on in vitro susceptibility testing. More clinical studies due to a lack of standard guidelines for the treatment of RGM infections are needed.

Enterococci as Increasing Bacteria in Hospitals: Why Are Infection Control Measures Challenging for This Bacteria?

Purpose of the reviewEnterococci are emerging threatening multidrug-resistant bacteria. Enterococcus faecium is a common pathogen associated with severe hospital-acquired infections. The goal of this report is to analyze the evolution of this nosocomial pathogen and study the state of adequate infection control measures.Recent findingsEvolution over millions of years has allowed enterococci to develop into a persistent hospital pathogen, an environment where it thrives. Vancomycin-resistant enterococci (VRE) continues to obtain antibiotic resistance elements. Enterococci assemble multiple virulence factors. VRE intestinal colonization can promote nosocomial infections. New rapid PCR laboratory tests with high sensitivity and specificity allows for screening of Enterococci in asyptomatic carriers.SummaryThe efficient clonal dissemination of VRE has led to a potential multidrug-resistant bacteria that is a current and future threat to hospitals worldwide. The therapeutic options are few and decreasing. Healthcare-associated infection (HAI) prevention is critical in our fight against enterococci.