The search for Helicobactor pylori; while the governments of two cities & two nations turn their backs on the Río Grande , Nuevo Laredoan Pablo Castillo speaks the simple truth

 

By Daniel Muñoa

 

On a cool February morning, Carlos Sanchez, a senior at Texas A&M International University who is majoring in biology and chemistry, accompanied me on a kayak excursion to the Mexican banks of the Río Grande to gather water samples from one of several spots where millions of gallons of raw untreated sewage flow unfettered into the Río Grande daily. After collecting samples from a sewage outflow on the Mexican bank at a spot 500 meters upstream of the Riverdrive Mall parking lot, Carlos and I spotted an elderly man walking his dog. He was about a hundred feet downstream from where we were. We wondered if he knew he was walking through sewage and decided to talk to him. As we approached, still wearing the surgical face masks that minimized our exposure to the many airborne pathogens from the untreated sewage, the old fellow greeted us with a wave of his makeshift cane. His dog issued a friendly growl. I introduced myself and told him what we were doing. He responded by stating his name, Pablo Castillo, and his dog's name, Camelo.

At 74, Pablo was proud to tell us that he had 13 healthy children, all grown and half of them living in the States. He said he was aware that untreated sewage was being dumped into the river and that it had and continues to have a negative impact on the environment. "No pasa un día que no encuentre un pescado, o una tortuga muerta al lado del Río" ("A day doesn't go by that I don't find a dead fish or turtle on the banks"). Pablo recalled a time not too long ago when the river flow was much greater and much cleaner than it is today. "¿Pero qué le vamos hacer, señor, si los gobiernos son los que tienen el poder y aparentemente, no les importa arreglar el problema?" ("But what can we do if the governments have the power to deal with the problem and it is not of any importance to them?")

He also said that he thinks he will live to see the day the Río Grande goes dry through Laredo. "Es cuestión de tiempo. El humano ha hecho lo que le dió la gana con la tierra, y ahora lo vamos a tener que pagar más probalmente por las malas que por las buenas" ("It's a matter of time. Man has done as man has pleased with the earth and now we will have to pay").

I stared quietly in astonishment as I listened to a man who by his own admission had no formal education as he spoke the dark environmental truth humanity faces at this very moment. We said our good byes and told him we hoped to run into him again sometime.

Carlos and I got back to the collection of water samples which will be used for basic scientific research. They will be screened for the presence of Helicobactor pylori in the molecular and microbiology labs of TAMIU by undergraduates under the supervision of Dr. Mario Garcia-Ríos, professor of Biology.

H. pylori is a poly-flagellated spiral gram negative anaerobic bacterium that is now known to be the main causative agent of duodenal ulcers, chronic gastritis, carcinoma of the stomach, and other gastrointestinal disorders previously thought to have been caused by stress and/or improper diet. More than five million cases were diagnosed last year, yet the source of H. pylori infection is still a hot debate in scientific and medical communities alike. Some argue that it's present in the drinking water; others argue that it spreads through consumption of uncooked vegetables that may have been handled by an infected field worker who decided to relieve his/her bowels while picking produce. In any event, seeing that many principal scientific investigators and medical doctors believe that H. pylori's reservoir in the environment is most likely linked to contact with human and/or non-human excrements of the gastrointenstinal tract, we concluded that the millions of gallons of raw sewage dumped into the Río Grande would be an excellent place to start looking for potential reservoirs of this pathogen.

Other reservoirs being considered for evaluation include uncooked vegetables and salsas from local restaurants and grocery stores. In addition, the common household cockroach will be screened as a potential vector for H. pylori.

What has made studying H. pylori difficult in the past is that it is difficult to culture in the lab. In other words, you can't simply take a tissue sample from a patient, place it on a conventional growth medium for bacterial culture, and expect to see growth, as in the case with E. coli and other gram negative enterics that grow rampantly once inoculated on the proper growth medium. Recently, however, scientists from the University of Wisconsin developed a plating medium that has exhibited excellent results in selectively culturing H. pylori. This newly developed plating medium, along with molecular-based DNA fingerprinting via PCR (Polymerase Chain Reaction), will be used to probe our local environment for potential reservoirs of H. pylori by students from TAMIU. This is the last scientific endeavor I will be part of at TAMIU before departing for medical school.

While the management and governance of two cities, two states, and two nations across the river from each other look away from the shared filth and the stench, along with the timid and ineffective International Boundary and Water Commission, millions of gallons of 100 percent toxic filth and pathogens cascade into the river while the binational wastewater treatment facility built in large part with American tax dollars operates at less than 50 percent capacity.

 

(Daniel Muñoa, a recent graduate of Texas A&M International University, will begin medical studies at the University of Texas Southwestern Medical Center - Dallas in August 2004.)